Effect of herbicides and interculture on nutrient uptake by puddle seeded rice and associated weeds.

A field investigation, conducted at Palampur during the kharif seasons of 1994 and 1995, revealed that application of pretilachlor 0.80 kg/ha at seven days after sowing (DAS) controlled weeds effectively and increased grain and straw yields significantly over weedy check and other herbicide treatments (butachlor 1.50 kg/ha, butachlor 0.75 kg/ha and pretilachlor 0.40 kg/ha). Weeds, when allowed to grow uninterrupted with the crop, depleted 65.41, 9.6 and 66.21 kg/ha nitrogen (N), phosphorus (P) and potassium (K), respectively. Use of herbicides increased nutrient uptake by rice and decreased nutrient uptake by weeds. Uptake of nutrients was higher by rice and lower by weeds with pretilachlor 0.80 kg/ha. Halod (interculture in standing rice crop) increased nutrient uptake by rice and decreased nutrient uptake by weeds significantly over no haold.