Effect of Foliar Spraying for Some Amino Acids on The Water Requirements of snap beans (phaseolus vulgaris l.) Plants

Snap bean (Phaseolus vulgaris L.) is one of the most important economic market crops in the Egypt. Also, the water is one of the major resources that limit agricultural developments especially in the arid lands so the shortage of irrigation water is the most important factor constraining agricultural production in Egypt. So, the field experiments were carried out during successive autumn seasons of 2019 and 2020 in EL-Kassasien Horticulture Research Station Ismailia Governorate to investigate the effect of water requirements rates (720, 960 and 1200 m³/ fed) combined with different concentrations of amino acids (100 mg/l, 150 mg/l and 200 mg/l) on vegetative growth, chemical composition of plant foliage as well as green pods yield and its quality of snap bean (Phaseolus vulgaris L. cv. Poulista) grown under sandy soil condition using drip irrigation system. Results showed that all vegetative growth characteristics (plant hight, leaves area, number of leaves as well as branches and fresh as well as dry weights of snap bean plants), chemical compision characteristics (N%, P%, K% and total carbohydrates contents), pods quality (average pod length, diameter and weight of snap beans pods) and pods yield as well as WUE were significantly increased with increasing rate of applied irrigation water in both seasons. In addition increasing amount of applied irrigation water from 720 to 1200 m³/fed. exhibited the highest values of most studied parameters of snap beans plants in both seasons of study. Results show also clearly that studied paremeters were significantly increased gradully with increasing concentration of applied amino acids from 100 up to 200 mg/l. In this respect, the highest values of studied parmters were represented in plants which were sprayd by highest concentration of amino acids(200 mg/L.) and were irrigated by highest level of irrigation water (1200 m³/F) followed by the plants which were sprayed by middle concentration of amino acids (150 mg/L.) and were irrigated with the same level of irrigation water during both seasons. Meanwhile the lowest values were obtained the snape bean plants which were irrigated by 720 m³/F of irrigation water and were sprayed with 100 mg/L. of amino acids.