Mohamed M. A. H. ( 2015). Effect of potassium fertilization on the growth, yield and quality of some sweet potato cultivars Minufiya J. Agric. Res. Vol.40 No. 2: 519 - 528
Abstract: Two field experiments were carried out during the two successive summer seasons of 2013 and 2014 in the Horticultural Research Station Al-Qanater El-Khairia, El-Kaluobia Governorate, Egypt to investigate the effect of four rates of potassium fertilization i.e., 0, 50, 75 and 100 % of the recommended does for sweet potato on the growth, yield and its components and qualities of some new sweet potato cultivars (Minufiya 2, 4 and 6) and check cultivar (Mabrouka). Significant differences were observed among potassium fertilization rates and cultivars and also for interactions (fertilizer x cultivars) on most of the studied characteristics. The cultivar Minufiya 6 had the highest values of total marketable yield of tuber roots as well as weights of tuber root and dry matter, while, Minufiya 2 cultivar had the highest value of tuber roots number per plant. The results also showed that growth characters of all used cultivars were significantly increased as raising the rate of potassium fertilization. Respect to quality characters sweet potato, there were no significant differences between the two rates of K 75 and 100 % for some traits such as percentage of dry weight root and total carbohydrates while, significantly increases were observed with increasing K rates in other traits such as sugars, carotene, vitamin C and protein. N content increases with increasing the rate of K from 75 to 100 % for all the used cultivars except Minufiya 2 cv. where was nosignificant difference between 75 and 100 % rates of K, values of P and K content where also similar at 75 and 100 % rates of K, while the uptake for NPK by tuber roots was significantly increased with increasing K rates for all cultivars under study. Accordingly, application of K fertilization 75% from the recommended dose of sweet potato is the recommended treatment at a rate of K 100% (96Kg K2O) for raising the productivity as well as improving tuber root quality and some mineral contents of new sweet potato cultivars compared with a check cultivar Mabrouka.
Keywords: (Sweet potato, potassium fertilizer rates, cultivar, uptake,)
