Effect of weed control practices on weed dry matter, production potential and nutrient uptake of sunflower (Helianthus annuus) in Vertisols

Abstract

Field experiments were conducted during rainy (kharif) season of 2006 and 2007 in Vertisols of semi-arid tropics, Hyderabad to evaluate the performance of sunflower (Helianthus annuus L.) for different weed control treatments. Preemergence application of pendimethalin (1.0 kg) in combination with interculturing at 21 days after sowing, followed by hand weeding was found as good as that of weed-free treatment in reducing weed growth and recorded higher seed yield and higher nutrient uptake of sunflower in Vertisols. On an average, weeds removed 39 kg N/ha, 8 kg P/ha and 53 kg K/ha in unweeded control. The activity of soil enzymes (urease, dehydrogenase and phosphatase) were enhanced/ maintained with application of pendimethalin at lower doses followed by intercultivation.