Green Seaweed Extract (Ulva Lactuca) as a Model for Bio Stimulating and Reducing of Chemical Fertilization on the Growth and Yield of Sweet Potato Plants.

Abstract

Seaweed is one of the most essential raw materials for the manufacture of bio-stimulant, which are processed and marketed for use in improving and maximizing agricultural production. Two field experiments were performed at the Agricultural Experimental Station Farm (Abies region), Faculty of Agriculture, Alexandria University during the 2016 and 2017 summer seasons. The study investigate the effect of NPK soil chemical fertilizers at the rates of 25, 50, 75% of recommended dose RD, in addition to 100% as a control treatment combined with application of seaweed extract Ulva lactuca (SWC) at the concentration of 0, 5, 10, and 15% as a foliar spray. The gradual increase in NPK chemical fertilizers had significant effects on growth, yield and chemical composition traits of sweet potato plants. The spraying of sweet potato plants with seaweed extract at a concentration of 15 % resulted in a positive response to all the traits tested. The application of NPK mineral fertilizer at the rate of 75% of the RD, combined with seaweed foliar spray at the concentration of 15%, was generally the most efficient treatment gave the best sweet potato growth, yield and tuber root chemical compositions Thus, this treatment can be decrease the NPK-chemical fertilizer by 25 % without sacrificing the output value of the sweet potato plants concerning the yield and quality of the tuber roots. KEYWORDS: