Abstract:
Investigation was carried out at Samsru during the 1984 wet season to observe the effect of nitrogen and phosphorus on the growth and yield of sweet potato. The treatments comprised three levels each of nitrogen and phosphorus (0, 6O and 120kg N/ha; 0, 30 and 60kg P2O5/ha) and two varieties (TIS 9265 and TIS 2498). The investination revealed that application of nitrogen affected the growth, yield components and yield of sweet potato, while phosphorus application had no effect on the growth, yield components and yield, Application of 60kg N/ha significantly increased the total and marketable yields by 58.2 and 75.2 per cent, respectively over the control. However increasing the level to 120kg N/ha significantly reduced these yields by 23.8 and 33.8 per cent, respectively when compared with the 60kg N/ha level. The number of tubers was significantly reduced by the application of 120kg N/ha, while the application of 60 and 120kg N/ha significantly increased the tuber weight. But the difference between the two levels was not significant. It was also revealed that the two varieties respond similarly to nitrogen fertilization, although variety TIS 2498 was superior over TIS 9265 in terms of total and marketable yields, the number of tubers, marketable tubers as well as vegetative character of dry matter production.
EFFECTS OF NITROGEN AND PHOSPHORUS ON THE GROWTH AND YIELD OF SWEET POTATO (Ipomoea batatas (L) Lam)
