Growth, yield, weed control efficiency and economics of sweet corn as influenced by integrated weed management practices under varying tillage practices

A field experiment entitled “Integrated weed management in sweet corn under different tillage practices” was conducted during rabi season of 2021-22 at Agronomy Main Research Farm, Department of Agronomy, College of Agriculture, OUAT, Bhubaneswar. The experiment was laid out in a strip plot design with three replications. Three tillage treatments were assigned to the main plot viz., T1-conventional tillage (CT), T2-zero tillage by dibbling (ZT) and T3- zero tillage+mulching with paddy straw @5 t/ha (ZT+M) and four weed management practices viz., W1- Pendimethalin and atrazine @0.5 kg/ha (Pre-emergence), W2-Pendimethalin and atrazine @0.5 kg/ha (Pre-emergence) fb one manual weeding 30 DAS, W3-Manual weeding at 3 0 DAS and W4-Weedy check. The soil of the experimental site was sandy loam in texture with pH 5.6, bulk density (B.D) 1.5 Mg m3, organic carbon 6.3 g/kg, available nitrogen 218.32 kg/ha, phosphorus 21.31 kg/ha and potassium 127.29 kg/ha. The sweet corn variety “Sugar 75” was grown as the test crop. Among the tillage practices, zero tillage +mulching was the best treatment. Among the weed management methods Pendimethalin and atrazine @0.5 kg /ha (Pre-emergence) fb one manual weeding 30 DAS was found to be the best. It recorded lowest weed density (46.81 no./m2). The interaction plot zero tillage+ mulching supplemented with Pendimethalin and atrazine @0.5 kg/ha (Pre-emergence) fb one manual weeding 30 DAS had the least weed density at 60 DAS (39.08 no/m2), least weed dry weight (19.3 g/m2 at 60 DAS), highest weed control efficiency (66.1% at harvest. It also resulted in better plant characters such as plant height (179.0 cm), LAI of 4.98 at 60 DAS, fresh cob yield of 18.20 t/ha and green fodder yield of 31 t/ha. Zero tillage practice along with rice straw mulching @5 t/ha and pre emergence application of herbicide Pendimethalin and atrazine @ 0.5 kg/ha fb one manual weeding 30 DAS resulted in highest net return of Rs 176000/ha and maximum B:C ratio (3.01), hence proved as the best treatment among all.