OPTIMIZING YAM PLANTING DATE AND POTASSIUM FERTILIZER LEVELS UNDER EGYPTIAN CONDITIONS.

Yam is one of the agricultural crops known and has great economic importance in many African and Asian countries, the most important of which is the production of starch and flour. Therefore, it is an alternative to wheat in the manufacture of bread, and successful cultivation of yam crop in warm areas, which means the possibility of growing large-scale in Egypt to contribute significantly to bridging the food gap in wheat. To study the effects of application of gibberellic acid (GA3) and benzyladinine (BA) on yam tubers dormancy and subsequent sprouting, pot experiment was done. To determinate the most appropriate dates for planting in Egypt and the best level of potassium for the highest productivity field experiment was conducted at the Experimental farm of Vegetable Crops and Medicinal and Aromatic plants Research Institute. Agriculture Research Center. Dokki, Giza, during the period of 2016/2017 and 2017/2018. The experimental design a split plot design with three replicates was used. The main plot was three different planting dates (1^st May, 1^st June and 1^st July. The sub plot was three levels of potassium fertilizer (96, 144, 192 K<subscript />form of potassium sulphate (48% K2O) and control treatment (without adding potassium fertilizer). The highest sprouting % (100%) was obtained with 1.0 mg/l BA. The combination between K2O at 144 kg/fed with 1^st June swing date gave the highest vine length, leaf area, Total chlorophyll, total yield/fed and total yield/ha of both seasons. [ABSTRACT FROM AUTHOR]