EFFECT OF IRRIGATION WATER QUANTITY AND SOME ANTIOXIDANTS ON YIELD AND SOME PHYSIOLOGICAL TRAITS OF SNAP BEAN GROWN UNDER SANDY SOIL CONDITIONS

Abstract

A field experiment was carried out during the two successive summer seasons of 2017 and 2018 under sandy soil conditions at EL-Khattara Experimental Farm, Fac. Agric., Zagazig University, to study the effect of irrigation water quantity (1000, 1500 and 2000 m3/fed.) and foliar spray with some antioxidants (salicylic cid at 200 ppm, ascorbic acid at 300 ppm beside control treatments ( sprayed with tap water ) on growth, plant water relationship, yield and pod quality of snap bean cv, Bronco. The most important findings could be summarized as follows: The interactions between irrigation of snap bean plants at 2000 m3/fed. and spraying with SA at 200 ppm recorded the highest values of dry weight of branches, leaves and total dry weight/ plant, increasing chlorophyll a, b and total chlorophyll (a+b) in leaf tissues, average pod weight , yield / plant and total pods yield/fed., and TSS in green pods. However, the interaction between irrigation water quantity at 2000 m3/fed. and spraying with ascorbic acid at 300 ppm recorded the highest values of total and free water (%) in leaf tissues and total carbohydrates and Vit. C in green pods in both seasons, whereas interaction treatment between 1000 m3 water/fed., without antioxidants resulted in the highest values represented bound water and proline amino acid in leaf tissues and total fiber contents in green pods. On the other hand, the interactions between irrigation water quantity at 1000 m3 water/ fed., and spraying with SA at 200 ppm recorded the highest values of water use efficiency (2.692 and 2.731 kg green pods/m3 water) in the 1st and 2nd seasons, respectively.