Sequential Application of Pre and Post Emergence Herbicides for Weed Control in Rainfed Maize

A field experiment was conducted during Kharif 2013 atthe Main Agricultural Research Station, University of Agricultural Sciences, Dharwad to studythe effect of sequential application of pre and post-emergence herbicides in maize under rainfed situation. The experiment consists of ten treatments which were laid out in Randomized Complete Block Design with three replications. The data on weed control rating revealed good to excellent control of weeds in post-emergence spray of Glyphosate and Paraquat at 7, 14 and 21 days after spray. Crop toxicity was noticed in postemergence spray of Oxyfluorfen at 7 days after spray, but crop recovered later. The lowest dry weight of the weeds (2.5 g m⁻²), total number of weeds, weed index and higher weed control efficiency (91.68) was recorded in Atrazine @ 1 kg a.i. ha⁻¹ +2IC +1HW and Farmers practice 2IC +2 HW which were on par with Glyphosate @ 2.5 kg a.i.ha⁻¹ and Paraquat @ 1 kg a.i. ha⁻¹. The highest grain yield (64.2 qha⁻¹) of maize was obtained with Atrazine @ 1kg a.i.ha⁻¹ + 2IC+ 1HW was due to higher yield components like cob length (18.33 cm), cob girth (17.0cm), test weight (34.4g) and grain weight plant⁻¹ (102.0g) but it was on par with Farmers’ practice 2IC + 2HW (61.7 qha⁻¹). With respect to economics, the application of Paraquat @ 1 kg a.i. ha⁻¹ and Glyphosate @ 2.5 kg a.i. ha⁻¹ was recorded higher net returns (¹. 42279 and ¹. 42150 ha⁻¹) and B: C ratio (2.47 and 2.43, respectively) compared to other treatments.