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SALINITY OF THE SOIL AND THE RISK OF DESERTIFICATION IN THE SEMIARID REGION

The salinity of the soils is one of the problems that most contribute to the degradation of the soils of the regions susceptible to desertification. This problem is present in many parts of the world, including Brazil. In this context, the objective of this article is to analyze the process of salinity of the soils in different land uses in municipalities of the Mesoregion of São Francisco (semi-arid of the State of Pernambuco). For this, samples of soils collected on diverse uses and occupations of the lands were submitted to chemical tests besides the identification of the class of soil to which each sample belongs. The results indicate that the areas on irrigated agriculture present the main sources of salinity, mainly in the places where the irrigation is performed through underground water. Unidentified problem on the samples collected in the Caatinga and partially found on the areas of exposed soils and those submitted to temporary agriculture (dryland). In the study region, inadequate agricultural management is one of the main responsible for salinity of the soils, and the impacts contribute to the increase of the risks to local desertification.

INTRODUTION
Desertification is a dynamic process developed from land degradation in arid, semi-arid, and dry sub-humid areas of the world, resulting from the environmental characteristics of these areas, as well as from the anthropic practices of resource exploitation in the mentioned areas. (UNNCCD, 2014).
It is estimated that much of the land located in dry climates present problems or marked risks to desertification (D 'ODORICO et al., 2013). You can name cities such as Mexico (BECERRIL-PIÑA et al., 2015); India (VARGHESE & SINGH, 2016) and in other parts of the world. In Brazil, the scenario is no different. In the Brazilian region where the climate can be considered semi-arid, the risks of desertification are eminent, and in some places the degree of land degradation is so severe that they have become a desertification core. (BRASIL, 2007;PEREZ-MARIN et al., 2012).
Something in common unites more than half of the risk areas, or in an advanced state of desertification, it is the dynamics of land use and occupation. According to D ' ODORICO et al. (2013), the use of agricultural land and dry forests without proper planning and management favors the degradation of soils and the reduction of biodiversity in these environments. Among the engines of desertification is soil salinization, which is the result of the accumulation of soluble salts in the arable land layers (LUO et al., 2017). As a consequence, there is plant poisoning and increased osmotic pressure on the vegetation inserted in salinized areas. (PEDROTTI, 2015;GKIOUGKIS et al., 2015), resulting in vegetation cover and agricultural production losses.
The salinization process is due to environmental characteristics and anthropic actions . Natural characteristics include the transport of salt sediments from salinized areas to unsalted sites; actions of ascent by capillarity of the soils to surface; high rates of evapotranspiration, among other factors BRADY & WEIL, 2012;PEDROTTI, 2015;WALTER et al., 2018).
The human actions that contribute to salt accumulation are varied, highlighting: the use of water containing high quantities of salts ; irrigation practice without drainage system; application of fertilizers and pesticides with a high salt concentration in their composition KANZARI, et al., 2012;PEDROTTI, 2015;SALVATI & FERRARA, 2015).
The impacts of soil salinization directly affect the dynamics of the spatial organization of populations, promoting the reduction of agricultural production, population displacement, highlighting the food security and economy of affected communities. Several studies point to the problems previously mentioned, especially Haron and Dragovich (2010) in Australia, Xu et al. (2014) in China, and in the Northeast of Brazil with Souza, Queiroz, and Gheyi (2000) and Vasconcelos et al., (2013).
Assessing the degree of salinization, the risks and the main contributing factors to the excess salt in the soils of desertification-susceptible areas becomes crucial, since it is a fundamental factor for the planning and promotion of public actions and policies for the proper management of each environment. In this context, the present study aims to analyze the degree of soil salinization in different land uses in municipalities of the Mesoregion of São Francisco, semi-arid state of Pernambuco, and its possible contribution to the process of local desertification.
The study area was selected based on the survey developed by Castro and Santos (2015), which showed that the municipalities studied have 39% of their territories with medium susceptibility to salinization. Other factors affected the selection and development of this study. These include the importance of the part of the local lands for the development of irrigated agriculture, frequent use of underground water for irrigation in non-irrigated agriculture areas, and rudimentary knowledge about the process and impacts of salinization of local soils

Study Area
The study was performed in the municipalities of Petrolina, Lagoa Grande, Dormentes, Afrânio, Mercator, Fortaleza, v.19 , e19002, 2020. ISSN:1984-2201 2/13 and Santa Maria da Boa Vista, western Pernambuco state (Figure 1), and belonging to the São Francisco Pernambucano Mesoregion. Both municipalities are under semi-arid climate, with an annual average rainfall of 700 mm concentrated at the end and beginning of each year; caatinga vegetation; soils with medium to few degrees of development; terrain marked by the "Sertaneja" Depression and inselbergs (BELTRÃO et al., 2006). The economic structure in these municipalities varies, even though the basis is the agricultural production with an emphasis on the irrigated fruit sector in the municipalities of Petrolina, Lagoa Grande, and Santa Maria da Boa Vista, and the goat and sheep livestock in the other municipalities. (IBGE, 2017).

Methodological procedures
For the development of the present study, sixteen samples of soils were collected, together with pieces of information regarding land use and occupation (Table 1). For data collection, we used: field books, Global Positioning System (GPS) receiver apparatus, plastic packages, cameras, and tape measures.
The criteria for choosing the locations for soil sampling considered the use and occupation of the land in the following categories: caatingas, rainfed/exposed soil and irrigated agriculture. Each sampling was performed in a 30 cm profile (root area of the plants) with the removal of approximately 1 kg of soil.
The samples were sent to the Soil Laboratory of the Federal Institute of Sertão Pernambucano (IFSertão), a rural zone campus, where the analysis of pH (Hydrogenionic potential), EC (Electrical Conductivity) and ESP (Exchangeable Sodium Percentage) was performed. Analyses were performed according to the EMBRAPA Soil Analysis Methods Manual (2011). In the laboratory, the first step was the exposure of the collected materials for moisture loss, followed by the screening process with 2 mm mesh. For pH definition, a table pH meter was used. The pH "is a measure that allows describing the acidic or basic character that predominates in an aqueous medium, considering its value determined on a scale from 0 to 14" (LEPSCH, 2011, p.210-211). The pH below 7 classifies the soil as acidic, the pH 7 is neutral while the pH above 7 indicates an alkaline soil.
For the EC analysis, a vacuum pump was used to remove the liquid part of the samples that were moistened 6 hours before the analysis. The sample taken was analyzed through the table Conductivity meter and the results presented in dS.m-1.
Where: is the exchangeable sodium content in cmolckg -1 , and the CEC is the capacity of cation exchange in cmolckg -1 obtained by summing Ca, Mg, Na, K, and H+Al.
The exchangeable sodium grade was assessed according to the EMBRAPA (2015) classification, in which the soil with ESP: less than six is considered low; 6 to 15 is medium, and values above 15 are rated high. ESP, the initially proposed methodology by Bohn et al. (1985) was used and presented in Table 2. The salinity effect on vegetation was assessed according to Richards (1954) was used, as described in Table  3, using CE. Table 3 -Soil salinity classes according to effects on vegetation cover. Fonte: Richards (1954).

Irrigated agriculture
Figures 2A, 2B, and 2C show the pH, EC, and ESP of the 6 soil samples, respectively, collected in areas under irrigated agriculture. The data highlight that the pH ranged from 5.35 to 6.88, among the samples. These values can be classified below neutrality with slight degrees of acidity ( Figure 2A). AM1 presented pH 6.88, which was the closest to neutrality. In this context, none of the samples in irrigated agriculture presented alkaline pH.
The acidic pH values in irrigated agriculture environments result from the frequent presence of water that contributes to the leaching of non-acid cations responsible for increasing the pH values. Generally, when the amount of acid cations increases, the pH of the soil solution tends to decrease (BRADY & WEIL, 2012). Provin and Pitt (2017) described similar results. The authors claimed that the high amount of water used in the irrigated systems plays a crucial role in reducing pH through the leaching process.

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Francelita Coelho Castro -Antonio Marcos dos Santos EC values ranged from 0.30 to 11.72 dS.m-1 ( Figure 2B). The samples AM4 and AM5 displayed values of 0.30 and 0.61 dS.m-1, respectively, being the lowest conductivity results found for irrigated agriculture. Values that classify these as non-saline, according to the Richards (1954) classification. However, when analyzing the management implemented in the sampling area, concerns arise about the future chemical status of some of the soils in irrigated agriculture areas. These concerns arise because, in these samples, farmers use furrow irrigation ( Figure 3B) over a Planosol.
Planosols present, in the A horizon, sandy or medium sandy texture; however, in the B horizon, there is a high activity clay, thus providing drainage difficulty (EMBRAPA, 2006). Lepsch (2011) observes that in many places in northeastern Brazil the Planosols are Natric. That is, they have characteristics of high sodium saturation.
Based on the two studies mentioned above, drainage deficiency and high sodium saturation are risk factors for the salinization of these soils if they are poorly managed, as it has been occurring in the case study area.
The AM1 samples, taken from a Quartzarenic Neosol, AM2 over a Luvisol, and AM3 over an Argisol present an EC of 3.55; 2.07 and 2.20 dS.m-1, respectively ( Figure 2B). Although Quartizaren Neosols are well-drained, the EC value found in their sample is the result of years of irrigation and lack of drainage engineering built in the area under Carica papaya (papaya) plantation in Petrolina ( Figure  3A). The soils of the AM2 and AM3 samples have a textural B horizon that hinders rapid infiltration, a feature that favors the permanence of water over the arable horizon and, consequently, accumulating salts. Taking into account the number of salts found in the soils of the AM1, AM2, and AM3 samples, the Richards (1954) classification classifies these samples as slightly saline based on the values found for EC, which ranged between 2 and 4 dS.m-1.
The highest value found for EC was in the sample AM6, municipality of Dormentes, totaling 11.72 dS.m-1, classifying this sample as highly saline, according to Richards (1954). One of the factors justifying the high EC is the use of water extracted from local aquifers to irrigate corn (Zea mays) and buffelgrass crops (Cenchrus ciliaris) ( Figure 3C). Much of the underground water in the municipality of Dormentes have high salt concentrations according to Ramos (2014). Consequently, the use of these waters in irrigated agricultural activities increased the concentration of salts to the Fluvic Latosol significantly, where the samples AM6 was sampled, and, consequently, contributing to increasing the risks of desertification in these areas.
Another feature that favors the high EC value in sample AM6 is its location, which is just after foothills and in the flood area of an intermittent stream. As for the proximity of the foothills, according to , this favors salinization by receiving salts from the higher surrounding areas, by the gravitational effect. About the flooded areas, the soils located there tend to present salinization problems due to the almost constant presence of water during the rainy season, which results in the accession and Mercator Figure 2C). The samples with the lowest ESP were AM1, AM3, and AM4, with values of 2.35%, 1.67%, and 2.56%, respectively. In samples, AM2 and AM5 the ESP, with values between 6 to 15% was considered average, according to EMBRAPA (2015). In sample AM6, underground water irrigated agriculture area in the Dormentes municipality, ESP was 25.34%, above 15%, which according to EMBRAPA (2015) is considered high. The value in sample AM6 is due to soil characteristics as well as local land-use practices, as previously mentioned. Above 15% ESP, according to Pistocch et al. (2017) indicates severe soil deterioration due to excess sodium.
For a better understanding of the concentration and distribution of the salts in the soils was used the Bohn et al. (1985) classification described in Table 2. This classification combines pH, EC, and ESP. Among the six samples, AM6 presented the worst result. The result is because this sample presented ESP higher than 15%, EC higher than two dS.m-1, and pH lower than 8.5. Combinations that classify the soil in this sample as saline-sodium. Problems reported previously because of high-salt concentrations in underground water used on a Fluvic Neosol.
Saline-sodium soil is characterized by the presence of soluble salts and sodium (EMBRAPA, 2006). The amounts of sodium and soluble salts found in the analized samples are sufficient to cause osmotic stress and other damage to vegetation development (FERREIRA, SILVA & RUIZ, 2010).
The samples AM1, AM2 and AM3 displayed a slightly better situation. According to the classification of Bohn et al. (1985), they are considered saline. The classification is defined because the pH was below 8.5, EC above 2 dS.m-1, but the ESP did not exceed 15%.
Saline soil presents an accumulation of soluble salts, which usually are flocculated and which permeability is similar to that observed in non-saline soils (FERREIRA, SILVA & RUIZ, 2010;. Despite the favorable permeability, care should be taken in the studied samples due to the presence of salts on their surfaces and the high susceptibility of these soils to salinization, since the soil of AM2 is Luvisol and in the sample AM5 Planosol. For the other samples, AM4 and AM5, the combinations of the three analytical parameters classify them as normal according to the classification of Bohn et al. (1985). The classification of these soils as normal was performed according to the individual EC and pH assessments presented above. These samples derived from soils susceptible to salinization (Table 1), but the use of irrigation techniques without the use of furrows, the distance from the São Francisco river in comparison to the other samples, and the recent banana cultivation performed in these same locations probably influenced the results of normality of these samples. Figures 4A,4B and 4C show the pH, EC, and ESP of soil samples, respectively, collected in areas under rainfed agriculture (cultivation in the rainy season) and exposed soil ( Figure 5).

Rainfed agriculture/Exposed soil
The results displayed small pH variations, between 4.79 to 7.04 ( Figure 4A). Considering the land use of the collection points, our analyses displayed that almost all the samples were taken from exposed soil sites. Only AM12 was collected from rainfed agriculture, resulting in a pH of 6.64 considered slightly acidic. The AM8 samples displayed the lowest pH value -4.79, being considered as acid and unproductive soil for several crops. The pH of the sample AM9 was 7.09, characterizing this soil as very close to the neutralized one.
For the EC values, the points on rainfed agriculture/exposed soil displayed a discrepancy of 0.21 to 35.94 dS.m-1 ( Figure 4B). AM12 ( Figure 4B) presented the lowest EC value for rainfed agriculture/exposed soil, which was 0.21 dS.m-1. According to these results, the sample could be classified as non-saline soil. What would you expect from a flat area over Fluvic Neosol, which according to Silva, Silva, and Barros (2008) has relative salinity potentiality? An area with salinization problems would be expected if not for management. In this area, located in the municipality of Petrolina, family farming practices use water only during the rainy season. This factor, compared to areas on Fluvic Neosols under active furrow irrigation, do not present salinization problems. Mercator, Fortaleza, v.19 , e19002, 2020. ISSN:1984-2201

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Francelita Coelho Castro -Antonio Marcos dos Santos However, the samples AM8, AM9 and AM10 displayed high EC values: 21.23; 35.94 and 7.97 dS.m-1, respectively. AM8 and AM9 sampling points presented similar land use and soil types (Luvisols) and are currently in an area abandoned for productive disability resulting from decades-long rice cultivation using the flood irrigation method ( Figure 5B).
Sample AM10 (EC: 7.97 dS.m-1), on exposed soil without traces of agricultural activities, presented slightly lower EC values compared to the samples previously discussed. This sample belongs to a Fluvic Neosol that, according to Silva, Silva, and Barros (2008), has a susceptibility to salinization and is classified according to the methodology of Richards (1954) (Table 3) as moderately saline. Figure 5 -Areas under rainfed agriculture/exposed soil where samples were collected. (A) exposed soil in salinized area in N7 irrigation project municipality of Petrolina; (B) salinized area in the 11 irrigation project municipality of Petrolina; (C) area intended for rainfed agriculture and exposed soil in the municipality of Afrânio. Source: elaborated by the authors, 2017.
For this class of use, also, the ESP values of the samples ranging from 0.77% to 63.90% ( Figure  4C) were analyzed. Sample AM12 ( Figure 4C) recorded the lowest result of ESP (0.77%), EC (0.21 dS.m-1) and pH (6.64). Results that, according to the parameters of Bohn et al., (1985), classifies this sample as normal for the presence of salts, thus being indicated for agricultural use within the proper management practices. However, the alert should always be lit, since the local soil is a Fluvic Neosol, Mercator, Fortaleza, v.19 , e19002, 2020. ISSN:1984-2201

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SALINITY OF THE SOIL AND THE RISK OF DESERTIFICATION IN THE SEMIARID REGION which has great potential for salinization.
Samples AM8, AM9 and AM10 presented the highest ESP values for exposed soil/dryland use category: AM8 (47.43%); AM9 (63.90%); AM10 (45.68%). Given the values considered by EMBRAPA (2015) as high, due to being above 15%, the data of our research display that the places where these samples were taken presented a severe salinization process. Results also found in the field due to the presence of plants adapted to the presence of salts in soils such as Shoreline Purslane (Sesuvium portulacastrum) (figure 5A and 5B), as well as the presence of surface salts ( Figure 5B).
When jointly analyzing pH, EC and ESP for the exposed soil/dryland samples the highlight remains the samples AM8, AM9, and AM10, both classified by the methodology of Bohn et al. (1985) as saline-sodium resulting from the past management and soil characteristics. The others were classified as normal. Figures 6A, 6B, and 6C show the pH, EC, and ESP of soil samples, respectively, collected in areas on caatingas ranging from shrub to small-sized caprine and cattle cultures, to arboreal and conserved rupestrian. (Figures 7A, 7B e 7C). The pH values for the areas on the caatingas did not show large differences between the samples, ranging from 5.44 to 6.26 ( Figure 6A). These values can be explained by the homogeneity of the caatingas that differ only in tree or shrub with small rocky areas, being areas without significant changes resulting from anthropic actions that favor the concentration of salts in soils. For the values of EC, a variation of 0.16 to 2.00 dS.m-1 was recorded ( Figure 6B). The value of 0.16 dS.m-1 was the lowest found for the caatingas, as compared to the areas of rainfed/exposed soil and irrigated agriculture. In the caatingas, all recorded values of EC were less than 2 dS.m-1, which place the soils as non-saline according to the Richards classification (1954). Given this analysis, it can be observed that the anthropogenic interference in the soils is fundamental to make them saline because in the other classes of land use were recorded values of EC, which indicate the presence of salts in soils higher than those found in the caatingas areas.

Caatingas
Also, the ESP values for the caatingas samples were verified, which ranged from 1.26% to 2.49% ( Figure 6C). According to EMBRAPA (2015), the amount of exchangeable sodium between the caatingas is classified as low, that is, values below 6%. The highest ESP caatinga area is located on Litholithic soil without human activities.
By jointly analyzing the pH, EC, and ESP for the caatingas, taking into account the Bohn et al. (1985) classification in all samples, the soils were classified as normal, i.e. without salinization problems. This result computed the structure of the land use, and the conservation of caatingas areas that have not been submitted to irrigation activities, even with soils that according to Barros, Barros and Silva (2008) present moderate risks to salinization such as Argisols and the Cambisols.
Among the land use classes, the caatingas present the smallest problems with salinization and, consequently, reduced contributions to the local desertification process. This is clear, considering only one of the indicators of this environmental problem.

CONCLUSIONS
In the study area, salinized soils, as expected, are mostly concentrated in areas intended for irrigated agriculture. The impact is more significant in environments where underground water is used for irrigation: underground waters have higher concentrations of dissolved salts, in addition to the features of the soil in which the agricultural activities are performed. Consequently, the contribution to the desertification process in these areas is more significant and follows a trend from various regions of the earth where agricultural management is a major contributor to the salinization and desertification correlation.
Regarding the areas of exposed soil, the samples that presented salinization problems were those derived from areas that had been abandoned from the agricultural activity due to salinization problems. The caatinga areas did not present salinization problems, although in some samples the soils are susceptible to salinization. These results prove that inadequate agricultural management in the study area is a major contributor to the salinization of local soils.


s2fieldsofstudy:
Agricultural And Food Sciences
Environmental Science

provenance: AgriculturalAndFoodSciences,2019-2020-Agricultural And Food Sciences-2020.jsonl.gz.gz

text:
Effect of hail net on the water potential of an apple orchard

Apples are grown in the largest areas in the Northern Great Plain in Hungary with an average apple production of 550–600 thousand tonnes, which is the 5 largest in Europe (Gonda and Csihon, 2018). Areas where all the conditions are favorable and intensive plantations with a high plant number provide 40–45 t ha yield. Due to the continental climate, frost damage is frequent in autumn, spring and winter, and the occurrence of drought is significant in summer. Domestic plantations are able to produce an average yield of up to 30–40 t ha during these effects, (Gonda and Apáti, 2011). Apples have an average annual heat demand of 10–11 °C according to their agro-ecological needs and prefer acidic soils to pH 5.8–7.0 (Kállay, 2014). Apples are a water-demanding fruit species, requiring about 750–800 mm of precipitation/year. It is highest water demand is from the beginning of June to the end of August. The quality of the fruit and the safety of the crop can be endangered by intensive plantations even if the critical water supply lasts only a few days during this period (Petesné, 2008). The use of hail net an intensive plantation supplement can be very useful and economical (Szabó, 2016), since hail can cause a serious problem in apple cultivation, where even a small amount of ice can degrade the apple so that it can only be sold for juice production (Kadosa, 2010). Use of the hail net have some positive effects on a given stock, one of the most important of which is temperature, where it plays a role in reducing extreme fluctuations. Another advantage is the possibility of water-saving production since the wind speed decreases, so the amount of water evaporated by the trees will be reduced by 30–40% (Lakatos et al., 2011). The plant water potential is the chemical potential of a system or part of the system water, expressed in terms of pressure, relative to the chemical potential of pure water. The value of water potential is highest in soil and lowest in air, and gives a temporary value from soil to air in the plant under normal conditions (Ördög and Molnár, 2011). The value of water potential, due to environmental reasons, is a key variable in the functioning of plant life. The two basic factors that determine the value of water potential are the concentration of solutions and the value of hydrostatic pressure. The gradient of water pressure in xylem as well as negative pressure can be detected. Scholander (1965) constructed a thick-walled pressure chamber container in which the leaf or fold was sealed and pressurized into an opening, and the leaves were placed in a chamber to measure the pressure present in the leaf or fold. In a closed container, the pressure was increased until the plant sap appeared on the cut surface (Boyer, 1967; Teszlák, 2008; Bratek et al., 2013). The pressure that water exerts on the cut surface indicates how much stress the leaf is experiencing in the water supply. High pressure means high water and high tension which vary within species and breeds. The water potential value in plants and its measurement has recently received considerable attention as water potential indicates the need for water within the plant. High water potential values affect the physiological processes of the plant, including slowing down or total stopping of photosynthesis, which reduces plant growth and ultimately causes plant death. This value can serve as a guide for improving growth and yield. Its unit is expressed in megapascal (Mpa) (McDowell et al., 2008; Klein, 2014; Steppe, 2018). Since the effect of hail net on the water potential of apple canopy thus on the water balance of apple orchards is not well studied, we aimed to analyse the effect of the hail net on the water supply and balance of apple orchards based on measuring water potential of apple canopy and microclimate data.

INTRODUCTION
Apples are grown in the largest areas in the Northern Great Plain in Hungary with an average apple production of 550-600 thousand tonnes, which is the 5 th largest in Europe (Gonda and Csihon, 2018). Areas where all the conditions are favorable and intensive plantations with a high plant number provide 40-45 t ha -1 yield. Due to the continental climate, frost damage is frequent in autumn, spring and winter, and the occurrence of drought is significant in summer. Domestic plantations are able to produce an average yield of up to 30-40 t ha -1 during these effects, (Gonda and Apáti, 2011). Apples have an average annual heat demand of 10-11 °C according to their agro-ecological needs and prefer acidic soils to pH 5. 8-7.0 (Kállay, 2014). Apples are a water-demanding fruit species, requiring about 750-800 mm of precipitation/year. It is highest water demand is from the beginning of June to the end of August. The quality of the fruit and the safety of the crop can be endangered by intensive plantations even if the critical water supply lasts only a few days during this period (Petesné, 2008). The use of hail net an intensive plantation supplement can be very useful and economical (Szabó, 2016), since hail can cause a serious problem in apple cultivation, where even a small amount of ice can degrade the apple so that it can only be sold for juice production (Kadosa, 2010). Use of the hail net have some positive effects on a given stock, one of the most important of which is temperature, where it plays a role in reducing extreme fluctuations. Another advantage is the possibility of water-saving production since the wind speed decreases, so the amount of water evaporated by the trees will be reduced by 30-40% (Lakatos et al., 2011). The plant water potential is the chemical potential of a system or part of the system water, expressed in terms of pressure, relative to the chemical potential of pure water. The value of water potential is highest in soil and lowest in air, and gives a temporary value from soil to air in the plant under normal conditions (Ördög and Molnár, 2011). The value of water potential, due to environmental reasons, is a key variable in the functioning of plant life. The two basic factors that determine the value of water potential are the concentration of solutions and the value of hydrostatic pressure. The gradient of water pressure in xylem as well as negative pressure can be detected. Scholander (1965) constructed a thick-walled pressure chamber container in which the leaf or fold was sealed and pressurized into an opening, and the leaves were placed in a chamber to measure the pressure present in the leaf or fold. In a closed container, the pressure was increased until the plant sap appeared on the cut surface (Boyer, 1967;Teszlák, 2008;Bratek et al., 2013). The pressure that water exerts on the cut surface indicates how much stress the leaf is experiencing in the water supply. High pressure means high water and high tension which vary within species and breeds. The water potential value in plants and its measurement has recently received considerable attention as water potential indicates the need for water within the plant. High water potential values affect the physiological processes of the plant, including slowing down or total stopping of photosynthesis, which reduces plant growth and ultimately causes plant death. This value can serve as a guide for improving growth and yield. Its unit is expressed in megapascal (Mpa) (McDowell et al., 2008;Klein, 2014;Steppe, 2018). Since the effect of hail net on the water potential of apple canopy thus on the water balance of apple orchards is not well studied, we aimed to analyse the effect of the hail net on the water supply and balance of apple orchards based on measuring water potential of apple canopy and microclimate data.

MATERIALS AND METHODS
The research was carried out in an intensive apple orchard with a drip irrigation system at the Horticultural Experimental Plant of Pallag, University of Debrecen. The orchard is located on sandy soils with extreme water content and stress caused by water scarcity is high risk on this area (Nagy, 2014). Our tested varieties were Early Gold and Golden Reinders. There are 100 trees in each row, the first 50 are protected by an hail net and the second 50 are not protected by an hail net. Sampling was performed twice weekly, between 9 and 10 am, 15 July 2019 to 29 August 2019 for 6 weeks, when we measured the temperature, humidity, and water potential values ( Table 1). We were taken the leaf samples from shaded portions of marked trees of homogeneous stands at identical heights. A suitable device for measuring water potential is the Pump-Up Chamber (PMS Instrument Company), in which the pressure chamber presses the leaf or the drive. Water potential values were measured at the time of sampling of 10 specimens of each species protected with hail net and 10 samples of individuals without hail net. Soil samples were not collected to detect the soil moisture content, because of the homogeneity of both soil physical and chemical characteristics of the investigated 0.5 ha orchard (Nagy et al., 2011). Furthermore, the utilized water for irrigation were also homogenous.
At the beginning of the measurement leaf or shoot specimens are bladed from the test plant 10 minutes after being placed in the sampling bag. After removing the Pump-Up Chamber's chamber pins and the chamber cover, the stem is inserted into the hole in the center of the lid, and the compression opening is rotated clockwise to tighten the seal around the pattern. We should be continuously monitored during pumping the samples. Each pumping takes approx increase the pressure by ½ bar when the plant sap appears on the sample, stop pumping and read off the pressure. A pressure relief valve is used to completely relieve the pressure and the following sample can be measured after removal of the taps and vent cover (Fulton et al., 2014) (Figure 1). .

Source: PMS instruments Company
The obtained water potential results were performed using R software in the R studio user environment using the agricolae package (Mendiburu, 2019) to determine significant differences between the results. Statistical analyzes included mean, standard deviation, minimum and maximum values using the Shapiro-Wilk test and the Duncan-test.

Effect of hail net on the microclimate
Microclimate data were collected during the studies, the measured parameters were the temperature and humidity, on which the hail net can have a positive effect, in correspondence with Lakatos et al. (2011) study. Early Gold shows the positive effect of hail nets on these parameters. Humidity is nearly the same or higher in the area below the hail net. Taking into account the temperature, the positive effect of the net can be seen, since the hail net reduces the high temperatures. Based on our values it can be observed that the temperature difference is 1-2 ° C in each of our measurements. Early Gold 6 measures the time of the morning with the consistently high temperatures already in the morning. Low humidity was obtained during prolonged high temperature and low precipitation (Figure 2).

Figure 2: Early Gold temperature and humidity values
Based on the results the positive effect of the hail net on the Golden Reinders was detected (Figure 3). The humidity increasing effect of the hail net is positive for almost all measurements and lowers the temperature compared to the non-mesh area. The low humidity was measured due to the absence of rainfall and high temperatures, with peak temperatures reaching 29 °C in the morning as Early Gold.

Effect of hail net on the water potential of Early Gold
The water content of plants is subject to negative pressure, it is scientifically stated that the water potential of plants (Stem water potential -SWP) is given as negative values (Fulton et al., 2014). The mean value of hail net individuals was -8 bar, while the average value of without hail net individuals was -11 bar, the difference was not significant (p=0.837). In the case of Early Gold the individuals protected by the hail net had higher water potential values at each measurement point, which indicates the better water balance of the individuals, thus the effect of the hail net on the plant water balance (Figure 4). There is no statistical difference between populations marked with the same letter as index character (p>0.05)

Effect of hail net on the water potential of Golden Reinders
Taking into account the water potential values of the Golden Reinders individuals, mean values of -8 bar was measured for the individuals protected by the hail net, which in all cases were higher than the without hail net, except for one sample. Unprotected individuals produce an average value of about -11 bar, there was a significant difference between the water potential values of the protected and non-protected stocks (p=0.030). The effect of the hail net foliage on the water potential of both varieties is positive at each measurement time, justifying the moderation of the effect of the use of hail net due to changes in stress due to water scarcity and high temperatures. It can also be stated that the water potential of the plants decreased continuously during the vegetation period which can be explained by the prolonged high temperature and the precipitation-free period besides the phenological changes ( Figure 5).

CONCLUSIONS
On the basis of the water potential values of both species it can be observed that higher values were obtained for the individuals protected by the hail net. Higher values gave better water potential, so the positive effects of ice protection nets prevailed in the study, since in both species 10 times better results were obtained from the samples protected by ice nets. Positive effects of the use of hail net were observed for water potential measurement values, temperature and humidity values for both species. Furthermore, there is lack of available Hungarian references for measuring the water potential of apple orchards, so these are the preliminary results of the Hungarian investigation.


extfieldsofstudy: Medicine Biology

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Assessment of growth characteristics, the survival rate and body composition of Asian sea bass Lates calcarifer (Bloch, 1790) under different feeding rates in closed aquaculture system

One of the essential factors to be addressed in the development of aquaculture is the feeding regime. This study was investigated to assess the effects of feeding rate on growth performance, feed utilization, chemical body composition survival rate, cannibalism and morphological indices of Asian Seabass, Lates calcarifer. Intended for the trial, one hundred forty sea bass individuals with an average weight 5.47 ± 0.11 g were randomly distributed in 4 concrete tanks (914 cm × 183 cm 122 cm) each; length × width × depth) and volume 18,399 L, for total 68 days. The fishes were fed with a pelleted diet containing 46% crude protein for different feeding groups designated as (T1, T2, T3 and T4). The feed was supplied with a rate of (T1) 3%, (T2) 4%, (T3) 6%, and (T4) 9% of fish biomass per day and feeding frequency were maintained three times per day to all the groups. At the end of the trial water physicochemical parameters was in acceptable range for Asian sea bass growth. The average daily weight gain (g), weight gain (g) and specific growth rate (%) was significantly higher (p < 0.05) in T3 and T4 as compared to T1 and T2 group. The poorest feed conversion ratio was recorded in T1 group with 3% biomass per day. The cannibalism rate was significantly (p < 0.05) higher in T1 (3%) compared to T3 and T4 treatment. The morphological indices, condition factors (CF), viscerosomatic index and hepatosomatic index (HSI) was significantly higher in T4 group as compared to other treatments. The protein, moisture and ash contents of the whole biomass of the Asian sea bass were not significantly influenced by feeding rate. The fat levels in the fish bodies increased significantly (p < 0.05) with increasing feeding ratio. The phenomenal regression indicates that 6.5% feeding rate per day is optimum for best growth performance, survival and minimum cannibalism rate for Asian sea bass in captivity. The outcome of the finding will help in promotion for not only the coastal aquaculture in Pakistan abut also elsewhere.

Introduction
Asian sea bass, Lates calcarifer is considered a most probable applicant species appropriate for aquaculture. Also, Asian sea bass is a comparatively hardy fish which embraces a broad variety of salinity from freshwater to complete saline water with 0-56‰ salinity and has wide physiological tolerances. It has been cultured in marine ecosystems, ocean nursery, brackish estuaries and fresh waters either as monoculture or in polyculture (Sorphea et al., 2019;Ganzon-Naret, 2013). L. calcarifer is widely https://doi.org/10.1016/j.sjbs.2020.11.056 1319-562X/Ó 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). distributed in the Western Pacific region, Arabian Sea, Taiwan, China, and Thailand (Venkatachalam et al., 2018;Narat, 2013;Anil, et al., 2010). This fish is extremely carnivorous an opportunistic predator with cannibalistic character and protandrous hermaphrodites (Boonyaratpalin, 1997).
Currently, aquaculture actually plays a crucial role in the culture of marine species for food and nutritional reliability. It is the fastest increase in the food production industry to reduce wild stock overexploitation and keep the ecosystem from declining (Daet, 2019: Sangeeta et al., 2018. In sustainable aquaculture practice, the management of fish nutrition is necessary to minimize costs and maximize growth performance for example, an optimal feed rate, the quantity of nutrition ingested by fish per day, is needed to handle fish nutrition for the best possible growth performance and fish health (Ahmad et al., 2018). The feed and feeding is considered the main factor in production cost of aquaculture, it represent from 50 to 60% of the total production cost in aquaculture investments (El-Sayed, 1999). So, the feeding control and determination of the optimum feeding rate is essential to success the culture of marine and fresh water fish. Knowledge about feeding levels is important to achieve the best growth and feed efficiency and preventing water quality deterioration as a result of the overfeeding then the optimum feeding level contributes in tremendous savings of the feed cost (Davies et al., 2006). There are many factors influence the optimal feeding level such as fish size, species, age, feed quality rearing condition (Goddard, 1995). Numerous studies have been evaluated the effect of feeding rate on growth performance of fish species such as yellow fin sea bream Acanthopagrus arabicus (Ahmad et al., 2018), Rabbitfish Siganus rivulatus (Mohammed et al., 2017), snapper Lutjanus johnii , grouper Epinephelus polyphekadion (Al Zahrani et al., 2013), black sea turbot Psetta maxima (Aydin et al., 2011) and rainbow trout Oncorhynchus mykiss (Bureau et al., 2006). Therefore the present study was planned to determine the optimum feeding rate of L. calcarifer on the growth output body composition, feed consumption, survival rate and cannibalism in a controlled environment, taking into account the limited information available on the optimum feeding rate for Asian Sea bass cultured under closed system in Pakistan.

Design of feeding trial
The trial was conducted at the Sindh hatchery seed production unit Hawkes Bay (24°86 0 2.08 00 N, 66°84 0 7.48 00 E) during October 2019 to January 2020. The Asian sea bass seeds were imported from Thailand commercial seed hatchery. A total of one hunred and forty fish individuals with initial body weight 5.47 ± 0.11 g selected and randomly distributed in four concrete tanks; the dimensions of each tank were (914 cm Â 183 cm 122 cm) each; length Â width Â depth) and volume 18,399 L. All the groups' fish were acclimatized for 2 weeks before the start of the trial. Four feeding rates were tested in this trial [T1, 3%, T2, 4%, T3, 6% and T4, 9%, of body weight per day (BW/d -1 )]. The total experimental duration was 68 days and the feed was supplied three times a day. Water was exchanged at a rate of 30 % the water volume per two days for maintaining the best water quality. After twohours of feeding, the uneaten feed was removed from the water (dry and weight).

Experimental feed preparation
The experimental feed was formulated to contain 46% protein and 20.9 KJ/g gross energy All ingredients were ground to small particles and mixed by hand. The ingredients (g/100) and a proximate analysis of feed were shown in Table 1.

Samples collection and Biochemical analysis
The biochemical analysis of feed and fish carcass samples were conducted according to (AOAC, 2000). At the end of study four fishes were taken from each tank and then dissected to weigh the liver and viscera then determination of hepato and viscerosomatic index (HSI, VSI).
The methods of (AOAC, 2000) have been used to evaluate crude lipid (CL), moisture and crude protein (CP). Moisture was measured at 105°Celsius for 24 h using an oven (Labostar-LG122 Tabia Espec, Osaka, Japan). Chloroform/methanol (2:1v/v) extraction procedure was predicted for crude lipid (Folch, et al. 1957). Crude protein was analyzed using an automatically processed Kjeldahl (Buchi430/) using a Kjeltec method (N Â 6.25) using, automatic Kjeldahl system (Buchi 430/323) model1265, Moline IL, USA) and Ash content was determined by ashing at 550°C in muffle furnace for three hours. and Gross energy (GE) was estimated for formulated diets the factors 23.62, 39.5 and 17.56 KJ/g for CP, EE and carbohydrates respectively were used (NRC, 1993).

Water quality management
Water temperature (°C), salinity (‰), dissolved oxygen (ppm) and pH were recorded every day and they were measured by (Celsius glass thermometer), and Handheld Refractometer, mobile digital DO-meter (Model: HI9146) and digital pH mete) , while ammonia (mg/l), alkalinity (mg/l), nitrate (mg/l), and nitrite (mg/ l) were determined every two weeks with chemical methods according to (APHA, 1995).

Statistical analysis
The experimental results were analyzed by One way analysis of variance (ANOVA) the differences among the treatments were determined by Duncan Waller at significant level (P 0.05) technique was used to test the determine biological and chemical indices of fish, between treatment means for the diverse feeding rate. The data were statistically examined by software SPSS version 20.

Growth performance
The results obtained from the feeding trial are set out in the Table 3 and indicated that, growth performance of Asian sea bass fingerlings significantly varied with difference of feeding rates.

Feed utilization parameters
There was a significant difference among the treatment at level 0.05 in FCR and PER.
Asian sea bass fed at 6% of biomass recorded the best FCR (0.96) and the highest PER (1.70, g). FCR and PER were insignificant between T2 and T4 but T2 was better in FCR (1.23) than T4 that had FCR (1.36). The fish fed at 3% of their biomass were the worst in FCR (2.04) and PER (1.36).

Morphological indices
The means of CF, HSI and VSI significantly increased with an increasing the feeding rate. Whereas, the highest CF value was 2.95 g/cm 3 and it achieved with T4 while CF of the other treatments did not significantly differ. No significant changes were found among T2, T3 and T4 in HSI and these treatments were significantly higher than T1. There was a significant positive correlation between values of VSI and increasing of feeding rats, the highest VSI recorded with T4 (5.20%), T3 (4.98%), T2 (4.30%) and the least VSI value was 4.11% with T1.

Cannibalism and survival
It is noted that (T1) fish fed 3% body weight had the highest cannibalism in comparison with the other treatments, where there was an adverse correlation between cannibalism and a high feeding rate. Survival rate was improved with increased the feeding rate up to 6% of biomass than it decreased with increasing feeding rate to 9% of body weight. Table 3 showed significant differences in survival rate among the treatments, T3 and T2 had the best survival rate followed up T4 that had 97.14% and T1 that recorded 94.28%.

Proximate composition of fish carcass
The carcass proximate composition was calculated on basis wet weight and presented in Table 4 carcass content of moisture and protein did not significantly affected by feeding rates. Conversely, carcass content of lipid and Ash were significantly differed among the treatments. There was a positive correlation between the car- cass content of lipid and increasing of feeding rate, where lipid carcass of T4 was 12.9% followed by T3 (9.88%) and no significant between T2 and T3. In relation to Ash content, there was insignificant among T4, T3 and T2 in Ash content but Ash content of T1 was 5.58% and significantly higher than the other treatments.

Discussion
Water quality plays a crucial role as they have direct influence on the general health status of the cultured fishes (Al Zahrani, et al., 2013). The disproportionate feed increases the feeding wastage in closed aquaculture system causing degradation the water quality through its decomposition, production of ammonia and depletion of oxygen. (Puvanendran et al., 2003). Consequently, Poor water quality conditions reduced feed consumption, increased FCR value and reducing the survival rate (Santos et al., 2010;Björnsson and Ólafsdóttir, 2006). physicochemical parameters:-like temperature, salinity, DO, pH, ammonia, alkalinity, and nitrate did insignificantly variance by the testing of feeding rates and this parameters remained within the range acceptable for Asian sea bass culture as showed in (Table 2). Whereas, it is known that Asian sea bass has an extremely wide thermal tolerance range (15-40°C) also, Asian sea bass had the best growth when were reared at 22-35C°temperature. (Anil, et al., 2010;Tucker et al., 2002). Moreover, the optimum ammonia level for Asian sea bass is from 0.001 to 0.05. The increasing of ammonia level from 0.200 to 0.500 (mg/L) fish lead to increase the mortality rate (Venkatachalam et al., 2018). In general, the results of water quality in this study is compatible to grew Asian sea bass according to (Sangeeta et al., 2018).
The fish aquaculture industry is continuously growing in worldwide and fish feed is considered as one of the greatest challenge in aquaculture that is very impressive on production costs (Ahmad et al., 2018;Silva et al., 2007). Because the feed is 50% of the cost of intensive fish farming (Tacon and Metian, 2008), therefore, feeding rate is an important variable in fish development, it has a big role to reduce the feeding wastage and preservation of water quality hence reducing the water exchange and regulation the eaten feed. The following has discussed the effects of the feeding rates variation on water quality, growth parameters, feed efficiency, morphological indices, survival and cannibalism rates and also the composition of fish carcass.
The results of the present study manifest that, the best growth performance was recorded in fingerlings of sea bass (Lates calcarifer) fed at 6.0%BWd -1 with feedings of three times daily after a 68 day trial. A 6.0% BW d-1 feeding rate showed significantly higher SGR, WG and the best FCR and PER. But increasing the feeding level till 9% BW d -1 resulted in reducing the growth performances.
A classical of precise growth rate (SGR) plotted against the rising of feeding levels by second order line regression of sea bass growth (y = -0.0292x 2 + 0.3798x -2.9339; R 2 = 0.9266) showed a reduced growth rate at high and low feeding ration. According to polynomial regression the optimum feeding rate is 6.5% BW/ day estimated in the present study for the best growth performance (SGR) in L.calcarifer (Fig. 1). These results were in agreement with Singh et al., (2003) who reported that, the enhancement of feeding level result in increasing the growth rate of fish up to a maximum rate then the growth curve decrease. Ng et al. (2000) and Adebayo et al. (2000) they observed that, with increasing the feeding rate the growth rate enhancement at a higher rate than decreased at lower rate. In the same trend Wang et al. (1998) said that; feed consumption and growth curve increase with increasing the feeding level up to a given limit. Similar results were recorded with Deyab and Hussein (2015) who found the best feeding rate of Nile tilapia was 5%BW/day also Trushenski et al. (2012) noted that a maximum growth of juvenile Atlantic spadefish achieved between 5 and 7% BW/day with feeding frequency tree times daily. Cannibalism (%) 5.72 ± 0.00 b 0 ± 0.00 a 0 ± 0.00 a 0 ± 0.00 a 15 SR (%) 94.28 ± 0.00 c 100 ± 0.00 a 100 ± 0.00 a 97.14 ± 0.00 b The mean ± SD of treatments (n = 35) in the same row with a number of different super-scripts differs significantly between them (P > 0.05). .30 ± 1.6 c 9.32 ± 1.60 c 9.88 ± 1.8 b 12.9 ± 1.77 a Ash 5.58 ± 0.01 b 5.12 ± 0.8 a 5.10 ± 0.6 a 5.13 ± 0.8 a Values (mean ± SD, n = 3 and each tank consists of 35 fish per group in the same row with different superscripts are significantly different (P > 0.05). The optimal feeding rate differ due to many factors for example fish species, whereas juvenile yellow fin sea bream (Acanthopagrus arabicus) (7% BW/d; Ahmad et al., 2018), Clarias gariepinus (8% BW/ d, Marimuthu et al., 2011), tambaqui, Colossoma macropomum (10% BW/d; Silva et al., 2007), European seabass Dicentrarchus labrax(7% BW/d; Ng et al., 2000) and Clarias fuscus (6% BW/d; Anderson and Fast,1991). Age of fish species is one of the factor that effect on the optimum feeding rate, it can be noted that the small fish need a higher feeding rate than the larger fish in the same species. Definitely, Kalogeropoulos et al. (1992) found that, 4% BW/day was the best feeding rate of gilthead sea bream with an average initial weight 3 g while 6% BW/day was the best feeding rate of the same species with an average initial weight 1 g. Also, the feed quality is considered one of the impressive factors on the optimal feeding level, whereas the varying of ingredients in standard diet had a great effect on the feeding rate, it can be cleared that, fish meal replacing with plant protein from fish diets causes changing the feeding rate, also fish oil replacing with plant oil from fish diet influenced on the optimum feeding rate of Siganus rivulatus fry, whereas fry fed dietary fish oil had a maximum SGR at 9% BW/ day as feeding rate while those fed dietary linseed oil had a maximum SGR at 7% BW/day as it has been found by (Mohammed et al., 2017). the feeding frequencies per day that has an important role in regulating the operating's digestion and absorption and it has a direct impact on the optimum feeding rate, Asian sea bass gained higher SGR and growth efficiency when fed three times daily than fed two or once time a day at the same feeding rate (Biswas et al., 2010). The rearing conditions has significantly effect on the optimum feeding rate, in the same trend, recorded finding revealed that the optimum feeding rate of Juvenile Korean Rockfish was changed with the different of water temperature (Mizanur et al., 2014) moreover the photoperiod or the culture in outdoor allows to bloom the phytoplankton in the rearing ponds consequently the optimum feeding rate is lower than the culture indoor.
In regard to feed utilization parameters, the best FCR and PER was achieved with fish fed at 6% daily, consequently it can be said that the feed utilization parameters and the growth indicates agreed to T3 has the optimum feeding rate. Absolutely, an increasing the feeding rate at level higher than the optimum level result in a reduced of FCR, it could be observed that T3 had the best FCR followed by T2 and not T4, in addition to, feed efficiency linearly reduced with an improper feeding level or overfeeding that cause an overload of fish digestion system accordingly, FCR negatively affect. this was confirmed by Mohammed et al. (2017) cleared that, 5% BW/day as the feeding rate had the best FCR followed by 7% BW/ day while the feeding rate 9% BW/day had the worst FCR.
Several works agrees with our finding and exhibited that the feeding rate significantly effect on growth characters of fish such as (Mohammed et al., 2017;El-Saied et al., 2015;Du et al., 2006). The improvement of Asian sea bass as result of increasing of feeding rate up to the optimum rate attribute to the boosting of feeding level encourage to increase the availability of resources of amino acids, fatty acids, vitamins and minerals, hence there is surplus resources of absorbed compound that will be stored as glycogen or lipid in liver or muscles. Furthermore, an increase of feeding level allow to increasing the opportunity to eat causing less aggressive and less of the lost energy as a result of crowding and competition through the feeding operation, this opinion was supported by Ashley-dejo et al. (2014) who explained that, dominant individuals are less aggressive under the optimum amount of feed whereas feed is distributed to locations occupied by subordinates.
Morphological indices as CF, HSI, and VSI are used to determinate the natural and physiological status, this indicates can provide evidence on development, health, reserves of energy and the potential of fish to survive ecological stress. In a bad, uncomfortable and critical environmental condition, fish typically liver loss more energy and is a smaller size. The statistical analysis of morphological indicates confirmed that this indicates were significantly increased with increasing the feeding rate. This observation was in agreements with (Iqbal et al., 2015;Mizanur et al., 2014;Zakęś et al., 2006) on the contrary (Mohammed et al., 2017) found that, HSI did not differ among the treatments by the changed of feeding level, in the same trend (Du et al., 2006) ascertain that HSI did not effect with increasing feeding rate.
In view of survival rate and cannibalism, the increasing feeding level up to 9% of BW/day adversely affected the survival rate but 6% BW/day and 4% BW/day had the best survival rate this may be due to the negative effects of overfeed that cause overload on the digestion system consequently a deterioration of fish health, hence increasing the mortality. On the other hand, low feeding rate contributes to reduce the growth and survival rate as a result of increasing the hunger, consequently increasing of the aggression and predation rate as it was appeared in T1. The results of survival rate in this study did not agree with Mohammed et al. (2017) and Deyab and Hussein (2015) they noted that survival rate of siganus rivulatus was insignificantly differed with the different of feeding rates.
In the present study cannibalism decreases with an increase in the feeding rate from group T2, T3 and T4 was no recorded cannibalism. Although, the survival rate was not different significantly but the highest survival was recorded in T2 and T3 group, similar findings was noted by (Sangeeta et al., 2018). In the present research, the carcass composition (Table 4) was influenced by differences in the feeding rate. The moisture content was observed to be unchanged by the dietary level variability. Observance in terms of the impact of the feeding level of the entire body development, protein was not greatly influenced by the rate of feeding increased. However, lipid levels were significantly increased by increasing ration levels. Similar results were recorded by (Mohammed et al., 2017;Lee et al., 2016;Deyab and Hussein, 2015) they illustrated that, the whole fish body content of protein did not affected with increasing of feeding levels and body content of lipid significantly increased with increasing feeding levels.
Moreover (Du et al., 2006) noted that, spadefish fed a higher level of feed had a high level of lipid ion their bodies and protein and Ash content were not affected. Conversely, Begum and Vijayaraghavan (2001) suggested that, fish content of protein increased to a high feeding level while fish content of lipid inversely related to the feeding level.

Conclusion
Under the prevailing environmental condition of Pakistan the results might suggest that, the optimum feeding rate for sea bass (Lates calcarifer) fingerlings with an average initial weight 5.47 g in a closed aquaculture system is 6% of biomass per day. But according to the polynomial regression the optimum feeding level for L. calcarifer is estimated as 6.5% per day for better growth performance. This rate for this species achieved a significant increase in growth rate, feed conversion ratio survival and prevention of cannibalism. Feeding regime has the most important to regular the feed offered, preserve the water quality and reduce the production cost of Asian sea bass farming.


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Effect of different plant extracts and nanoparticles on Thrips tabaci (Lind.) (Thysanoptera: Thripidae) under field conditions and their allelopathic potential on the onion, Allium cepa L. using bioassays and RAPD analysis

The present study was conducted to investigate the toxicity of Aerosil 200® (fumed silica nanoparticles) and leaf extracts of four plants, Cinnamomum camphora, Matricaria chamomilla, Mentha arvensis, and Trigonella foenumgraecum against Thrips tabaci (Lind.) (Thysanoptera: Thripidae) in onion fields, as well their allelopathic effects on onions; moreover, the chlorophyll, phenol, and protein contents were determined in onions. This study was performed in completely randomized plots. After a growth period of 1 month, bioassay investigations and molecular polymorphism in T. tabaci by RAPD-PCR were performed, and total chlorophyll, phenol, and protein concentrations were investigated in onion plants posttreatment as well. The initial reduction% of the T. tabaci population in onion fields after application of a high concentration of nanoparticles (Aerosil 200® (4 ml/l)) and 8000 ppm concentrations of the four plant extracts were 83.66, 81.08, 86.92, 74.49, and 91.38%, respectively, whereas their persistence effects were 73.18, 67.78, 71.46, 66.94, and 78.29%, respectively. Furthermore, the total chlorophyll contents in onions treated with the nanoparticles and four plant extracts were 1.35, 1.17, 1.09, 1.07, and 1.18 mg/g, respectively; additionally, the concentrations of phenols were 4.65, 3.15, 3.15, 2.85, and 3.70 mg/g in onions treated with C. camphora, M. chamomilla, M. arvensis, T. foenum-graecum, and Aerosil 200®, respectively. The C. camphora extract was the most potent, as it increased the protein content in the onion plants, while the Aerosil 200® decreased the protein content in onions. In addition, DNA-RAPD showed that the polymorphism percentages were 73, 71, and 67% when treated with high concentrations of C. camphora and M. arvensis extracts and Aerosol 200®, respectively. T. foenum-graecum and M. chamomilla extracts induced the least polymorphism (17 and 16%, respectively). Overall, this study indicated that these plant extracts as well as the nanoparticles in Aerosil 200® could be used to reduce onion infestations of T. tabaci in the field environment.

Background
The onion (Allium cepa L.) is an important vegetable crop cultivated worldwide. Egypt is considered the largest dehydrated onion source in Africa and the Middle East. Iris yellow spot virus (IYSV) transmission via Thrips tabaci (Lind.) (Thysanoptera: Thripidae) has been reported in many countries, including Egypt (Abdelkhalek et al. 2019). Furthermore, onion plants are considered one of the main origins of dietary polyphenols worldwide (Knekt et al. 1996), and their consumption leads to the protection of DNA against oxidation. Polyphenols in dietary plants showed very important antioxidant activities (Singh et al. 2009). Additionally, they protect organisms from/against cellular damage (Martínez et al. 2007).
Devastating losses of annual onion crops occur due to disease transmission and can range from nonsignificant amounts of loss up to more than 50% of the total crop, depending upon many factors. Iris yellow spot virus is the most important disease transmitted by T. tabaci (Abdelkhalek et al. 2019). Disease symptoms of Iris yellow spot virus are similar to those of T. tabaci infestation and appear as eye-like, chlorotic, or diamondshaped lesions (Pappu et al. 2008). T. tabaci is among the major insect pests of onion crops and cause large amounts of damage to the crop by consuming the plant sap and/or by transmitting other diseases, including IYSV (Gent et al. 2006). Control strategies of T. tabaci include chemical insecticide treatments (Jensen 2005).
Heavy application and indiscriminate uses of chemical pesticides in insect pest management has led to the advancement of resistance in all classes of insecticides (Kranthi et al. 2002). On the other hand, using natural plant oils are encouraged in order to decrease the application of chemical pesticides and their residues (Murray et al. 2011).
Allelopathy (largely of secondary metabolites) refers to the harmful or beneficial effects of a plant on another plant through biochemical release from the plant parts, and the release of such chemicals may attract or repel insects. Additionally, allelopathy can affect many plant bionomics, including growth, plant succession, and plant productivity (Singh et al. 2001). Allelochemicals are the secondary metabolites of allelopathic organisms (Hanan M. 2016). Recently, plant extracts have been used for pest control as alternatives to chemical pesticides (Qari and Abdel-Fattah 2017). Several molecular techniques have been used to determine the ability of these plant extracts to reduce insect infestation. Random amplification polymorphism DNA PCR (RAPD-PCR) could be a good technique for the rapid identification of genetic changes on the molecular level (Qari 2010). RAPD-PCR has also been used to determine variations in the T. tabaci genome (Ramakrishnan et al. 2019). Moreover, plants offer a different and alternative source of insect biocontrol agents, as they contain a wide range of bioactive materials, and many of such compounds are selective or have no harmful effects on nontargeted organisms as well as the environment, unlike synthetic insecticides. Additionally, some of these bioactive materials have been shown to have repellent, antifeedant, and toxic effects and induce enzymatic changes in insects (Adakole and Adeyemi 2012).
This study was carried out to evaluate the effect of plant extracts and Aerosil 200® nanoparticles in reducing onion infestations of T. tabaci in the field using bioassays and molecular tools.

Plant extracts and tested material preparation
The effects of the leaf extracts of four plants, namely, Cinnamomum camphora, Matricaria chamomilla, Mentha arvensis, and Trigonella foenum-graecum, on the infestation of T. tabaci in an onion field, as well as their allelopathic effects on the onion plants, were studied. According to Qari (2008), powdered leaves of each plant were soaked in liquid nitrogen and 1000 ml distilled water for 72 h at room temperature for aqueous extraction and then kept in a dark at 4°C. The solutions were filtered and evaporated via rotary evaporation until the extracts were jelly-like in appearance and reach a final concentration of 1 g/l (1000 ppm). Two different concentrations were calculated and prepared (4000 and 8000 ppm) to be used in the bioassay.
On the other hand, nanoparticles (ca. 6.6-13.3 nm: Aerosil 200® as a silica oxide nanopowder, 99.8% SiO 2 ) was obtained from a commercial company in Egypt for scientific services (Tiba Company). The shape and size of the nanoparticles were verified by electron microscopy and prepared at two concentrations, 4 ml and 2 ml/l in order to be use in the bioassays.

Experimental design
Studies which evaluate the effects of different plant extracts, as well as Aerosil 200® nanoparticles, on T. tabaci in onion cultivation fields and their allelopathic effects on the onions were carried out at Kaha Agricultural Research Station Farm, Egypt, in March 2018. The onion cultivar Giza 20 was obtained from the Agricultural Research Center, Giza, Egypt. A backpack sprayer was used as for foliar spray. Onions were grown in completely randomized plots in the field; each treatment was repeated four times, and each replicate area was 4 m × 4 m. After 2 months of onion cultivation, the bioassay investigations were performed; concentrations of 4000 ppm (8 ml/2 l/64 m for each treatment) and 8000 ppm (16 ml/2 l/64 m for each treatment) were applied for the plant extracts, while the implemented concentrations of Aerosil 200® were 2 ml/l (4 ml/2 l/64 m) and 4 ml/l (8 ml/2 l/64 m). All tested materials were prepared and applied as foliar sprays on onions in the morning. Pretreatment counting in each plot was carried out, then the application performed and the reduction% of T. tabaci adults were counted after 1, 3, 7, and 10 days and corrected according to Henderson and Tilton (1955).

Onion parameter analyses
All biochemical studies were carried out on new onion leaves after applications of both concentrations of the botanical extracts (4000 ppm and 8000 ppm) and Aerosil 200® (2 and 4 ml/l).

Total chlorophyll
The assessment of total chlorophyll content was estimated in 85% acetone leaf extracts according to Metzner et al. (1965). First, the leaves were centrifuged at 14000 rpm, for 20 min then the absorbance was read spectrophotometrically at 663, 652, 646, and 470 nm. Finally, the concentrations of chlorophyll were calculated according to the following equation (Metzner et al. 1965): total chlorophyll (μg/ml) = A652 × 27.8.

Determination of phenols
One gram of onion leaves was ground in liquid nitrogen, extracted with 80% methanol (v/v) and heated at 85°C for 2 h. After cooling, phenol determination in the extracted leaves was estimated according to Denre (2014).

Protein content
According to Qari (2016), the protein content of each treated and untreated onion sample was estimated.

Sampling of T. tabaci and DNA extraction
Adult insects of T. tabaci were collected from different treated onions by shaking the treated plants onto a white sheet to gather the insects. The samples of T. tabaci were crushed and stored in TE buffer at − 20°C until DNA extraction. DNA was extracted according to the procedure described Oliveira et al. (2010). The insects were ground in liquid nitrogen, dissolved in 4% CTAB extraction buffer, mixed with 4 μL β-mercaptoethanol, and then heated for 30 min at 65°C. After centrifugation at 14000 rpm for 5 min, the supernatant was treated with cold isopropanol (v/v) for 20-30 min then centrifuged again at 14000 rpm for 5 min. DNA samples were precipitated, and the resulting precipitate was washed twice with 70% alcohol and resuspended in 0.1 ml TE buffer. The quality of the isolated DNA was quantified with a fluorometer and 0.8% agarose gel stained with 0.2 μg/ml ethidium bromide (EB) visualized under UV light.

RAPD-PCR analysis
The RAPD-PCR procedure was carried out on a final volume of 25 μl reaction mixture containing 20 ng genomic DNA, 1.5 μl PCR buffer (50 mM KCl, 12 mM MgCl 2 , 100 mM Tris-Cl, pH 9.0), 7.92 μl sterile deionized water, 1.8 μl dNTPs (0.1 mM each), 1.8 μl decamer primers (Operon Tech) as shown in Table 1 (4 mM), and 1.5 U Taq DNA polymerase. PCR was conducted in a Perkin-Elmer TC480 thermocycler as follows: one cycle at 94°C for 2 min; 45 cycles at 94°C for 10 s, 36°C for 30 s, 72°C for 1 min; and a final extension at 72°C for 2 min. The PCR products were separated by electrophoresis in 1% agarose gel, stained with EB, and visualized under UV and documented using Gel Documentation System software (Bio Rad, USA). Each primer yielding productive bands was repeated twice. Band sizes were specified by a DNA ladder.

Statistical analysis
Analysis of variance ANOVA was implemented with SPSS software. The percentage of DNA stability was estimated according to the following equation: 100 − (100 a ÷ n), according to Luceri et al. (2000), where n is the number of total bands in the control and a is the RAPD-PCR polymorphic bands detected in each treatment sample. The average for each treatment was used for evaluation. The reduction% was calculated according to Henderson and Tilton (1955) with the following equation: No:in control before treatment x no:in treatment after treatment No:in control after treatment x no:in treatment before treatment

Results and discussion
Average number of T. tabaci after treatment The results presented in Table 2 showed that the average number of T. tabaci adults ranged from 46.9 ± 4.4 to 28.55 ± 5.9 in the untreated control, while it ranged from 2.95 ± 0.9 to 9.55 ± 1.7, 8.45 ± 3.1 to 12.9 ± 4.2, 4.75 ± 1.9 to 11.95 ± 4.4, and 6.45 ± 3.7 to 12.65 ± 3.9 when 8000 ppm C. camphora, M. chamomilla, M. arvensis, and T. Reduction percentages of T. tabaci after application of botanical extracts and Aerosil 200® The data in Table 2 show that the reduction% of T. tabaci individuals 10 days after application was 61. 96-46.32, 46.88-28.15, 55.12-35.22, 49.37-25.36 Comparison based on initial and persistence reduction, potency level, and control index of Aerosil 200® and four phytochemical extracts on T. tabaci in onion fields The data shown in Table 3  Regarding the relative potency level of the initial reduction, the fold changes are shown in Table 4, it was found that the potency levels of C. camphora, M. arvensis, Aerosil 200®, and T. foenum-graecum were respectively 1.22, 1.16, 1.12, and 1.08 times greater than that of the M. chamomilla extract, while the potency levels based on the persistence of the different treatments descended as follows:   Sun (1950), the susceptibility index can describe and differentiate between treatments with a given arbitrary index value of 100 units for the most effective treatment. In this study, the most effective treatment was that with the C. camphora extract, so it considered the standard toxicant and given arbitrary index value of 100 units, and the reduction effect of tested compounds descended in the following order: C. camphora, M. arvensis, Aerosil 200®, T. foenum-graecum, and M. chamomilla. These results are in accordance with those of Shehawy et al. (2013), who concluded that plant extracts showed high reduction efficacy against T. tabaci.
Effect of plant extracts on the chlorophyll, phenol, and total protein contents in onion plants

Chlorophyll concentration
As shown in Table 4, there was a significant difference observed in the total chlorophyll concentration of onion leaves after 10 days of application for all treatments. The total chlorophyll concentration in the control was 1.08, while it was 1.20, 1.09, 1.09, 0.93, 1.01, and 1.11 mg/g dry weight, when the lowest concentrations of C. camphora, M. chamomilla, M. arvensis, T. foenum-graecum, and Aerosil 200® were applied, respectively, and that after application of the highest concentrations was 1.35, 1.17, 1.09, 1.07, and 1.18 mg/g dry weight. Overall, it can be concluded that there was a direct relation between the application of C. camphora and M. chamomilla with the total chlorophyll concentration in the onions, i.e., the greatest applied extract concentration was the greatest total chlorophyll concentration compared to that of the control. However, no significant differences in the chlorophyll content were observed when the lowest concentrations of M. chamomilla, M. arvensis, and Aerosil 200® were used compared to that of the control. Leaf senescence including chlorophyll loss (leaf yellowing) decreases the amount of photosynthesis occurring (Munne-Bosch 2007). Variations in the chlorophyll concentration of the plant may be due to the presence of some interactions of allelochemicals present in the plant extracts used in this study (Talukder et al. 2015).

Phenol concentration
The data in Table 4 show that the phenol concentration was 2. 15, 6.75, 4.78, 4.21, and 4.10 mg/g dry weight, in onions after application of the lowest concentration of C. camphora, M. chamomilla, M. arvensis, T. foenumgraecum, and Aerosil 200®, respectively. And that after application of the highest concentrations was 4.65, 3.15, 3.15, 2.85, and 3.70 mg/g dry weight, respectively, after 10 days. It could be concluded that treatment with the highest concentrations of C. camphora and Aerosil 200® correlated with a positive allelopathic effect (leading to increased phenol accumulation) compared to that of the control. However, application of M. arvensis and Aerosil 200® exhibited a negative allelopathic effect and led to a low concentration of phenols in the onions. Phenols in plants are involved in diverse processes, such as UV protection, plant pigmentation, plant nitrogen fixation, and disease resistance in the plant. Additionally, phenols, including flavonoids, are considered antioxidants and are medically important Abreu and Munne'-Bosch S. (2009). A complex allelopathic effect may inhibit growth of other plant species. Allelopathy is plant competition; it involves biochemical interactions, and it can involve Non-significant at P < 0.5 (there is no significant difference between data which given the same letter in the same column) Qari et al. Egyptian Journal of Biological Pest Control (2020) 30:13 both "inhibitory" and "stimulatory" responses from the same compound (Leicach et al. 2009).

Total protein
The data illustrated in Table 4 show that the concentration of total proteins, measured after application of high concentrations of C. camphora, M. chamomilla, M. arvensis, T. foenum-graecum, and Aerosil 200® on the onions was 77.4, 64.4, 60.35, 63.25, and 35.25 mg/g dry weight, respectively, whereas the total protein contents was 67.5, 58.65, 54.45, 57.75, and 47.47 mg/g dry weight, after application at low concentrations. The application of C. camphora at 8000 ppm increased the protein concentration the most after 10 days of application, followed by M. chamomilla, M. arvensis, T. foenum-graecum, and M. arvensis. Application of the nanoparticles in Aerosil 200® decreased the concentration of total protein, indicating that Aerosil 200® had a negative allelopathic effect on the onions. However, the four plant leaf extracts exhibited beneficial allelopathic effects on the onion plant protein content. Overall, it could be concluded that there was a strong inverse relation between insect infestation and the chemical constituents of the onion plants after the treatments. Allelopathy can affect many occurrences of plant bionomics, including growth, plant succession, and plant productivity (Singh et al. 2001).
Generally, the average number of polymorphic bands of the eight tested primers showed that the best harvested bands produced in RAPD-PCR were those of the primer OPH/11, which gave 6.4 bands, followed by those of OPA/11 and OPAL/20, which gave 5.2 and 4.8 bands, respectively. The lowest average number of polymorphic bands was produced by the primers OPAB/09, OPA/08, and OPA 19, which were 3, 3.2, and 3.4 bands, respectively (Table 5). Such a wide variation in the number of bands produced by these arbitrary primers may be attributed to the differences in the binding sites throughout the genome of T. tabaci.
Moreover, the polymorphism percentages in the present study indicated genetic changes in T. tabaci due to exposure to the different plant extracts as well as to the nanoparticles (Aerosil 200®). The results presented in Table 5 show that the polymorphism percentages were 73, 71, and 67% when the insects were treated with the highest concentration of the C. camphora and M. arvensis extracts and Aerosil 200®, respectively, whereas the T. foenum-graecum and M. chamomilla extracts induced the least polymorphism, yielding percentages of 17 and 16%, respectively, when compared to that of the control. The RAPD marker system distinguished the different impacts of different plant extractions and Aerosil 200® as expected since they were affected on vitality of T. tabaci. This result was corroborated by the reduction percentage of onion infestation. This might be the host-induced genetic variation as observed in Thrips (Brunner et al. 2004).
Many studies have shown that there is a strong correlation between the genetic variation in the Thrips genome and changes in the DNA bands produced with RAPD (Jenser et al. 2001). The present study showed the ability of several plant extracts (C. camphora, M. arvensis( and nanoparticles to cause genetic changes in Thrips. This result is consistent with that of many studies that suggested the ability of the Thrips genus to induce genetic modifications for pesticide resistance (Tsukahara et al. 2003), which may explain the global distribution of Thrips.

Conclusion
Overall, it can be concluded that using the aqueous leaf extracts, as well as the fumed silica nanoparticles had significant reduction effects on T. tabaci populations in an onion field. On the other hand, all of the plant extracts had positive allelopathic effects on onions by improving the chlorophyll, phenol, and protein contents in onion plants, but Aerosol 200® application was shown to decrease the total protein content.


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Standardization and comparitive study of chevon cutlets incorporated with shredded potato and radish

The present study was intended to standardize the recipe and procedure of chevon cutlets and to compare the effect of potato and radish addition in the product. Meat cutlets are ready to eat, crispy snack item and widely used in the breakfast. Chevon cutlets were prepared with cooked meat instead of minced meat with shredded potato and radish in 1:1 ratio (one part meat and one part potato/radish). Results revealed that chevon cutlets prepared with radish recorded significantly (P ≤ 0.05) lower PH, lower cooking loss, higher % of bread pickup, higher moisture, crude fiber and lower crude fat. Chevon cutlets prepared with incorporation of radish paste recorded significantly (P ≤ 0.05) higher juiciness and tenderness when compared to potato. Moreover, mouth coating is also well appreciated in radish incorporated cutlets. Hence, there is scope for inclusion of radish in cutlets by replacing the potato. Thus, good quality chevon cutlets could be prepared by incorporating radish paste instead of shredded potato.

Introduction
Meat cutlets are prepared to eat advantageous meat items that are exceptionally well known all through the world and generally utilized in the morning meal. Cutlets are flat croquette of meat, shredded potato, condiments, spices and often coated with rusk crumbs. The nutritive worth and tangible nature of the cutlets can be additionally upgraded by use of goat meat. Being less in cholesterol and fats and having minimum total calories, high potassium and low sodium the chevon cutlets will prove a better option for the non-vegetarian consumers. The ready to eat / ready to prepare (RTE/ RTP) food provided a reasonable choice to customers in the present occupied way of life. The goat meat is very popular and widely favored by the consumers in India. Chevon is a red meat that is often viewed as potential competitor to beef and mutton. It is almost universally acceptable and free from culture, tradition, social and economic conditions [1] . Incorporation of vegetables in meat products would serve as substitute for non-meat ingredients that will bring substantial cost reduction and also improve the nutritive value. The potato (Solanum tuberosum) is widely used in the development of food products and preparation of different variety of crispy food products including meat products [2] . Radish is a root plant related to mustard family and is one of the richest sources of iron and calcium among all common vegetables. It contains flavonoids such as kaempferol glycosides, peroxidases and antioxidants. The studies reported that radish extract showed antimicrobial and antimutagenic effects [3] . Thus, the present study was envisaged to standardize the recipe and to compare the effect of potato and radish addition in chevon cutlets.

Materials and Methods
Chevon cutlets were prepared with cooked meat instead of minced meat with shredded potato and radish in 1:1 ratio (1-part meat and 1-part potato/radish) and subjected them to quality analysis i.e. Physio-chemical characteristics like cooking loss, % bread pick up, pH, proximate composition and sensory evaluation. The cooking loss was recorded by noting the weight of cutlets before and after frying.
Weight of raw enrobed cutlets The rusk pickup percent was determined as per formula; noting the weights of cutlets before and after rusk pick up. [4] Weight of cutlet after dusting -weight of cutlet before dusting Rusk powder pick up Weight of cutlet before dusting The pH of fried chevon meat cutlets was determined as per procedure [5] . The proximate analysis was conducted as per the procedures [6] . Sensory evaluation of the product was carried out on a 9-point hedonic scale. Sensory evaluation panel consisting of nine members including faculty of CVSc, Proddatur, SVVU evaluated the cutlets. Coded samples for sensory evaluation were prepared and served warm to the panelists. Water was provided for oral rinsing between the samples. Each experiment was replicated three times and the data generated was analyzed using Two sample T-test [7] to determine significant differences (P≤0.05) between treatments.
Methodology: Preparation of Chevon cutlets with Potato /Radish was depicted in Figure.1.

Results and Discussion
The results obtained in the present study were depicted in the Table. 2. Cooking loss: Chevon cutlets prepared with Radish (T 2 ) recorded significantly (P ≤ 0.05) lower cooking loss when compared to Potato (T 1 ) which could be attributed to the higher moisture retention during cooking by radish fiber. The lower cooking loss in radish added cutlets in the present study well corroborated [8,9] .
Bread Pick Up %: Chevon cutlets prepared with Radish (T 2 ) recorded significantly (P ≤ 0.05) higher % bread pick up when compared to Potato (T 1 ) which might be due to increase in moisture content in the product which facilitates the large pick up of the rusk materials [10,11] . PH: Chevon cutlets prepared with radish recorded significantly (P ≤ 0.05) lower pH when compared to potato which might be due to lower pH and slight acidic nature of radish paste and comparatively higher pH of potato paste. The results obtained in the study were in accordance with the reports of carrot incorporated chicken sausages [12] and in turkey sausages [13] .

Proximate composition
Moisture: Chevon cutlets prepared with radish recorded significantly (P ≤ 0.05) higher % moisture than potato added cutlets. This might be due to relatively higher moisture content within the radish, higher water retention capability of those fibers, the soluble component of which mainly is pectin that will represent up to 30% of the fibers concentrate [11] . These results were in agreement with the chicken nuggets [14] , vegetable incorporated meat products [12] and in turkey sausages [13] .
Crude protein: Chevon cutlets prepared with potato recorded significantly (P ≤ 0.05) higher % crude protein than radish added cutlets which might be due to high % protein in potato than radish.
Crude fat: Chevon cutlets prepared with radish recorded significantly (P ≤ 0.05) lower % crude fat than potato added cutlets. Fat and moisture are two components which are firmly related in meat items and if fat substance is low, the moisture content is probably going to be high [15] . Similar results were also reported in chicken nuggets [14] , vegetable incorporated meat products [12] and in turkey sausages [13] .
Crude fiber: Chevon cutlets prepared with radish recorded significantly (P ≤ 0.05) higher % crude fiber than potato added cutlets which might be due to high fiber level in radish. This was found in agreement with the results of chicken nuggets [14] , chicken sausages [12] and in turkey sausages [13] .
Total ash: No significant difference was observed in total ash content of the both treatments.
Sensory Evaluation: Chevon cutlets prepared with radish (T 2 ) recorded significantly (P ≤ 0.05) higher juiciness, tenderness, mouth coating and overall acceptability when compared to T 1 (Potato) which might be due to high moisture retention and high rusk pick up in radish however potato added cutlets recorded significantly (P ≤ 0.05) high scores for appearance and flavor when compared to radish added cutlets which might be due to good appeal and dominant pleasant flavor of potato than radish. [11] [9] and also in turkey sausages [13] .

Conclusion
The results of this study revealed that chevon cutlets prepared with radish recorded significantly (P ≤ 0.05) lower PH, lower cooking loss, higher % of bread pickup, higher moisture, crude fiber, lower crude fat, higher juiciness, tenderness, mouth coating and overall acceptability when compared to potato. Hence, good quality chevon cutlets could be prepared by incorporating radish paste instead of regularly used shredded potato.