Effect of Weed Management in Rice Crop in Northern Zone Areas, Yield and Quality - A Review

Rice (Oryza sativa L.) is the most important staple food crop for more than half of the world’s population, including regions of high population density and rapid growth. In India, rice is the most extensively grown food crop, being cultivated on an area of about 43.42 million hectare with total production of 119.93 million tonnes and an average productivity of 2390 kg ha^-1. India is first in area under rice, while China is first in production. It provides about 21 per cent of the total calorie intake of the world population. Yield losses due to weeds vary with system of rice culture, variety, plant population, fertilizer applied, duration and time of application; weed species, amount of weed growth, season, ecology and climatic conditions. Weed management is an important key factor in obtaining higher crop yield. Reduction in yield to the tune of 34% in transplanted rice, 45% in direct seeded low land rice and 67% in upland rice are reported. Weeds compete for an adequate supply of the nutrients, moisture, light and the growing space. Successful weed management for rice more important to exploit its maximum production potential. Different weed management practices were studied in rice in present study were pretilachlor + bensulfuron methyl 70 g + 500 g a.i ha^-1 as pre emergence followed by mechanical weeding at 30 DAS/T, bispyribac sodium @ 50 g a.i ha^-1, farmer’s practice and weedy check. Among weed management practices, pre emergence application of bensulfuron methyl + pretilachlor mixture followed by mechanical weeding at 30 DAS/T resulted in higher B:C ratio compared to other methods of weed control.