EFFECT OF SPRAYING CHITOSAN ON PRODUCTIVITY AND FRUIT QUALITY OF MANFALOUTY POMEGRANATE TREES

Abstract

In order to investigate the effect of spraying Manfalouty pomegranate trees with chitosan at 0.0 (control), 50, 100, 200 and 400 ppm on yield (kg), fruit weight (g), number of fruit/tree as well as fruit physical and chemical properties of Manfalouty pomegranate (Punica granatium L), a field trial was conducted in two successive seasons (2018 and 2019) at a private farm located at El-Qusiya district (350 km southern Cairo city), Assiut Governorate. The obtained results confirmed that spraying Manfalouty pomegranate trees with chitosan at 50 ppm to 400 ppm significantly improved pomegranate fruits physical and chemical properties as well as yield (kg)/tree, fruit number/tree and fruit weight (g). This promotion was parallel with increasing chitosan concentration. However, non-significant differences were observed between the two highest concentrations used (200 and 400 ppm), during the two experimental seasons. INTRODUCTION The Pomegranate tree (Punica granatum L.) belongs to Myrtales order and Punicaceae family.. Pomegranate is an ancient beloved plant and fruit. The name ‘‘pomegranate’’ follows the Latin name of the fruit Malum granatum, which means ‘‘grainy apple.’’ The generic name Punica refers to Phoenicia (Carthage) as a result of mistaken assumption regarding its origin (Shulman et al., 1984; Morton, 1986; Holland et al., 2009, and Ampem, 2017). The pomegranate has gained high economic value in recent years due to the large volume of in vivo and in vitro studies attributing numerous health benefits to the fruit and its products (extensively reviewed in Holland et al., 2001; Fadavi et al., 2005; Holland et al., 2009; Fakhour 2012 and Franck et al., 2012). Over the past three decades, there has been a growing interest in developing natural alternatives to Ibrahim et al., 2020 100 synthetic polymers, namely, biopolymers. Chitosan is produced by deacetylation of chitin, which is the structural element in the exoskeleton of crustaceans, such as crabs and shrimp, and cell walls of fungi. Chitin is the second most prominent biopolymer after cellulose found in nature (Rinaudo, 2006 and Kim & Kim2011), due to their remarkable macromolecular structure, physical and chemical properties, and bioactivities, chitosan have received much attention in fundamental science, applied research, and industrial biotechnology (Dima et al., 2017; Philibert et al., 2017). This investigation aimed to study the effect of spraying chitosan (at 50. 100, 200, and 400 ppm) and frequencies of applications (once, twice and thrice) on yield and its components as well as fruit quality of Manfalouty pomegranate grown under Assiut Governorate conditions. MATERIALS AND METHODS The field work of this investigation was conducted during two successive seasons (2018 and 2019) at private orchard located at ElQusiya district, Assiut GovernorateEgypt, where the soil texture is heavy clay and water table depth is not less than two meters, surface irrigation system was used. Ten Years old, planted at 4 X 4 meters, uniforms in vigor, Manfalouty pomegranate trees were used in this investigation. Winter pruning was followed at the first week of January. 1Soil analysis: A composite sample of soil was collected and subjected to physical and chemical analysis according to the procedures outlined by Walsh & Beaton (1986) and Buurman et al., (1996). The data of soil analyses are shown in Table (1). Table (1): Physical and chemical analysis of experimental orchard soil.