Efficacy of Herbicides under Direct Seeded Rice Establishments

Change in method of crop establishment from traditional transplanting of seedlings to direct seeding has occurred in many rice growing countries in response to increasing production cost, especially for labour and water. It also aids in quick rice establishment, early harvest and thus early sowing of wheat. Sowing of pre-germinated rice seeds under puddled condition either manually or drum seeding method reduces the demand of water for puddling and minimized the emergence of weed flora by placing the seed, stems and stolens of weeds into sub-surface. Direct seeded rice is subjected to greater weed competition because both weed and crop seeds emerge at the same time and compete with each other from the germination as a result less grain yield. Uncontrolled weeds reduce the yield by 96 % in dry seeded rice and 61% in wet seeded rice. Control of weeds is important to reduce the weed competition as well as to maximize the efficient utilization of resources. Herbicides are considered to be an economical alternative to manage weeds against age-old practice of hand weeding, which is costlier and also becomes impracticable.