Growth, yield and nutritional quality of sweet pepper plants as affected by potassium and phosphate fertilizers varying in source and solubility

Abstract

The effects of phosphorus fertilization and foliar potassium on plant growth and fruit quality of sweet pepper plants were evaluated at a private farm located in Khatatba, Giza, Egypt, during two successive seasons (2014 and 2015) to investigated the impact of different sources of phosphate monoammonium phosphate (MAP), monopotassium phosphate (MKP), urea phosphate (UP) and calcium superphosphate (SP)) and foliar application of potassium as K2O (0, 100 and 200 ppm) on growth, nutrient content, photosynthetic pigments, ascorbic acid, total acidity, protein and fruit yield of sweet pepper plants (Capsicum annuum L.) cv. Gedeon,. The results showed that growth of pepper plants were affected according to the source of phosphate, application of MKP recorded the highest values of plant height, number of leaves and branches, plant fresh and dry weights as well as plant yield, meanwhile MAP gave remarkable improvement of plant growth and fruits characters as compared to control (adding SP). Application of UP recorded the least effectiveness on plant growth and yield parameters compared with SP as phosphorus source. An increase in photosynthetic pigments and minerals nutrition (N, P, K and Ca %) was recorded parallel to the increase of phosphorus availability (with MAP and MKP application). Foliar spray of K showed an enhancement of fruits number and weight, as well as total acidity and vitamin C concentrations. Therefore, an adequate management of fertilization with P and additive amounts of foliar K could improve yield and fruit quality of pepper plants as a result of stimulation of growth, and amelioration of some biochemical analysis