Effect of Nitrogen and Potassium Fertilization on Starch Content of Cassava Root

Abstract

During the 1982 - 83 growing season a study was made of the effects of rates of application of nitrogen (0,8, 16 and 32 kg/rai) and potassium (0, 20, 40, 80 kg/rai of K2O) on the starch content of cassava root. The study was undertaken on the Yasothon soil in Khon Kaen province in Northeast Thailand. At different growth stages the root starch content and leaf N, P and K contents were determined. Harvesting took place 12 months after planting. Starch content of the root decreased with increasing levels of nitrogen application. No significant effect of potassium on starch content was recorded. The results did not reveal any evidence of a ralationship between the N an dK content of the leaf and root starch content.