Dry matter accumulation, nutrient uptake and water use efficiency of sunflower as affected by application of irrigation and nutrients

摘要

Results of an rxperimenl conducted on spring sunflower showed that there was significant increase in dry' mailer accumulation with the increasing levels of irrigation. Three irrigations were found to significantly increase the uptake of N, P, K. andS over two irrigations in both the years. The total consumptive use (CU) of water increased with the increasing levels of irrigation up to four (632 mm). However, maximum WUE of 0.30 kg seed of sunflower produced per cubic metre water used for ET was recorded under three irrigations. Application of N. K and S was observed to significantly enhance the dry matter accumulation. Application of 80 kg N/ha significantly increased the uptake of N,K and S whereas application of P at 40 kg P_2O_5/ha incrased only the uptake of P. Application of 40 kg K_2O/ha significantly enhanced the uptake of N. P, K and S. Addition of S improved the N, K and S uptake but discouraged the uptake of P in two years. Nitrogen and potassium enhanced the total CU by 48 and 72 mm,respectively but higher WUE was recorded due to N and K application.