Weed management in turmeric (Curcuma longa) through integrated approaches

A field study was conducted at Ludhiana during 2006–07 and 2007–08 and at Nawanshah during 2007–08 to find out effective and economical approaches for weed management in turmeric (Curcuma longa L.). Pre-emergence pendimethalin 1.0 kg, metribuzin 0.70 kg and atrazine 0.75 kg/ha, each integrated with one hoeing at 60 days, paddy straw mulch 6 t and 9 t/ha; paddy straw mulch 6 t (recommended), 9 t/ha alone and 6 t/ha + two hoeing at 60 and 90 days; three hoeing at 30, 60 and 90 days and unweeded control were evaluated. Losses in rhizome yield due to weeds vary from 63.9 to 76.5%. Straw mulch 9 t/ha significantly reduced weed dry matter and recorded 29.2% higher rhizome yield than 6 t/ha. Averaged over two locations, pendimethalin + straw mulch 9 t/ha revealed the highest weed control efficiency (84.2%), fresh rhizome yield (29.6 t/ha), herbicide efficiency index (11.2), net returns (10³×10³ Rs/ha) and benefit: cost ratio (2.30) and was at par with metribuzin and atrazine, both integrated with straw mulch 9 t/ha. The fresh rhizome yield with straw mulch 9 t/ha + herbicide combination was 48.2, 14.9, 15.3 and 225.5% higher than straw mulch 6 t, 9 t/ha alone, 6 t/ha + herbicide and unweeded control, respectively. Different weed control measures led to 104.8–289.1, 72.7–220.4 and 90.5–278.1% increase in N, P and K uptake by crop, respectively, over unweeded control. Uncontrolled weeds removed 60.6, 59.9 and 73.6% of total nutrients utilized by both crop and weeds. Integrated use of paddy straw mulch 9 t/ha with either of pendimethalin 1.0 kg, metribuzin 0.70 kg and atrazine 0.75 kg/ha was adjudged very effective for weed control and attaining the highest productivity and profitability in turmeric.