Cultivar and management of aerobic rice under agro-ecosystem in the northeastern Thailand

Abstract

On-station yield trials were conducted in 2 locations, Udonthani province represent as irrigated riceland and Khon Kaen province as rainfed riceland to evaluate effects of spacing (S) nitrogen level (N) and cultivar (V) on growth and yield of aerobic rice and irrigated rice. Split-split plot design with 4 replications was used in this study. Plant spacing of 25 cm. and 50 cm. as main plot, 3 nitrogen application rates 30, 60 and 90 kilogram/ha as subplot, and 4 rice cultivars namely, Sakol Nakorn (SKN), Sanpathong 1 (SPT1), Rice Department10 (RD10) and Sew Mae Jan (SMJ) as sub-subplot. The spacing did not show any significant difference under aerobic rice but significant difference under irrigated condition. Spacing of 25 cm. gave the highest grain yield. Nitrogen level and cultivar are significant difference among the treatment. Application of nitrogen at the rate 30 kg/ha gave the highest in grain yield. For cultivar, SKN produce the maximum in grain yield (0.83 ton/ha) under aerobic condition. Under irrigated condition, the lowland rice cultivars (SPT1 and RD10) gave the yield about 4-5 ton/ha.The upland rice cultivar (SMJ) had lower yield potential. For the farmer field yield trial were conducted in three sites at Nong Khai, Mahasarakam and Nakorn Ratchasima province to evaluated 6 aerobic rice cultivars by using wide spacing (50 cm.) and narrow spacing (25 cm.) with 2 levels of nitrogen application rate, by using split-split plot design in RCB with 3 replications. Summary of F-test show the significant difference for spacing, nitrogen level, cultivar and cultivar across nitrogen application rate especially for the drought-prone area like Nakorn Ratchasima, but non significant difference among Mahasarakam and Nong Khai where the amount of rain fall and its distribution over sufficient.