Timing of Basal Fertilizer Application on Rice-Weed Competition in Dry Seeded Rice

Abstract

Studies on timing of basal fertilizer application on rice-weed competition in dry seeded rice, at Nakhon Ratchasima
Rice Experiment Station, Chumpae Rice Experiment Station and Surin Rice Research Centre, in wet season, 2001- 2003. Two experiments were conducted with 2 rice cultivars both are Khao Dawk Mali 105 (KDML105) and Surin 1
(SR 1), respectively. The experiments were Split plot desing with 4 replications. Two main plots namely post emergence
with 2 , 4-D/propanil at the rate of 240 g ai/rai at 15 days after emergence (DAE) and unweeded. Sub plots wer 4 times of basal fertilizer applications by sowing at 15, 30 and 45 DAE, with the rate 2.4-4.8-4.8 kg (K-P2O5-K2O) /rai plus the rate of 2.4 kg (N)/rai at panicle initiation (PI) with KDML 105, and the fertilizer with rate 4.8-4.8-4.8 kg (N-P2O5-K2O)/rai and 2.4 kg (N)/rai at PI of JSR 1. Resultswere found that the experiment I with Khao Dawk Mali 105, there was not significat different between rice dry matter and weed dry weight when the fertilizers were applied at there sowing dates. Fertilizer that was applied at 30 DAE atfer weed control produced the highest grain yield. Experiment 2, there was no significant different between unweed and weed control in thrm of weed dry