EFFECT OF FOLIAR SPRAY WITH DIFFERENT POTASSIUM SOURCES AND ZINC RATES ON GROWTH AND YIELD OF SWEET POTATO (Ipomoea batatas L.).

Abstract

Two field experiments were carried out during 2017 and 2018 seasons atExperimental Farm, Faculty of Technology and Development (Ghazala Region –Zagazig City), Sharkia Governorate (Egypt) to investigate the effect of different potassium sources and zinc fertilizer levels on growth and yield of sweet potato plant cv. Menoufia 6. The experimentwas set up arandomized complete blocks design which included 7 treatments of different sources of potassium and zinc (EDDTA)rates(i.e., potassium silicate 2 mll-1 and 4 mll-1, potassium humate, 2 mll-1 and 4 mll-1 and zinc (EDDTA), 2 mll-1 and 4 mll-1, besides the control treatment without any addition . The obtained results could be summarized as follows: application of foliar spray with zinc (EDDTA) with4 mll-1, being the most effective treatment on vegetative growth and chemical composition, while 4mll-1 potassium silicate as foliar application caused a significantly increased in tuber yield and quality of sweet potato, followed by the treatment of 4 mll-1 zinc in most cases, in both growing seasons. Conclusively, it could be concluded that, using the treatment of 4 mll-1 zinc (EDDTA) caused an increases in plant growth parameters and chemical composition of sweet potato plant cv. Menoufia 6, while 4 mll-1 potassium silicate significantly increased tuber yield and quality.