Foliar Application of Ascorbic Acid Combined with Nitrogenous Fertilizer Positively Enhanced the Response of Pea Plants

Abstract

This study was conducted on pea (Pisum sativum L.) cv. Master B in the Experimental Farm of Vegetable Research Station, Faculty of Agriculture, Mansoura University, Egypt during two winter seasons of 2015/2016 and 2016/2017 under silty clay loam conditions by using furrow irrigation system to investigate the effect of ascorbic acid (AsA), inorganic nitrogen (N) fertilization and their interactions on growth, productivity and quality of pea. Therefore, four concentrations of AsA, viz, 0, 100, 200 and 400 mg L -1 (ppm) applied as a foliar application combined with three N-fertilization levels, i.e., 60, 80 and 100 kg fed. -1 as a soil application were studied. The experiment was laid out as split plot in randomized complete block design (RCBD) with three replications. The obtained results revealed that fertilization of pea plants with 100 kg N/fed. combined with foliar application of AsA at 400 mg L -1 followed by 80 kg N/fed. with 400 mg L -1 of AsA gave significant increases for the traits of plant vegetative growth (plant height and fresh weight, branches and leaves number/plant, leaves fresh weight, leaves area/plant and partially leaves dry matter percentage), leaves chemical composition (N, P and K percentages and chlorophyll a, b and carotenoids contents), pods and seeds yield components (number and fresh weight of green pods/plant, green pods yield/fed., 100 seeds fresh weight and green seeds yield/fed.), seeds quality (Vit. C, TSS, total carbohydrates, crude protein, N, P, and K contents) and moderate values for both seeds nitrate (NO 3 ) and dry matter percentage of pea compared with control treatment (60 kg N/fed. only), without significant differences between two interaction treatments in both seasons. Concerning the effect of nitrogen fertilization levels, all above mentioned parameters significantly increased with increasing Nfertilization level from 60 kg /fed. to 100 kg /fed. and vice versa for leaves and seeds dry matter percentages and seeds nitrate (NO 3 ) content in both seasons. As for the impact of AsA, the rate of 400 ppm recorded significant increases for all forecited parameters with the lowest nitrate content of dry seeds compared with control treatment (untreated plants), with no significant differences among AsA concentrations in this respect in both seasons. Therefore, adding 100 kg N/fed. combined with AsA at 400 mg L -1 as a foliar application was the best treatment of which this study recommends to use followed by the treatment of 80 kg N/fed. + 400 mg L -1 of AsA to reduce the costs of production, environmental pollution and produce safe food for human health.