Bio-Efficacy of Early Post Emergent Herbicides and their Tank Mixtures on Weed Contol in Maize (Zea mays L.)
Loading...
Date
2016-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Science, Dharwad
Abstract
A field experiment to study the bio-efficacy of early post emergent herbicides and their tank mixtures on weed control in maize was conducted on black soil at Main Agricultural Research Station, UAS, Dharwad during kharif, 2015. The experiment consisted of 12 treatments laid out in randomized complete block design. The treatments consisted of atrazine, 2,4-D, tembotrione, topramezone and their tank mixtures applied at 16 DAS as early post-emergent herbicides, they were compared with recommended weed management practice (atrazine 1.25 kg ha-1 (PRE) + 1HW + 1IC), weed free and weedy check.
The results indicated that among the tank mixtures, significantly lower weed density (7.67 0.5 m-2), weed dry weight (4.89 g 0.5 m-2), weed index (7.07 %), NPK uptake by weeds (2.0, 0.36, 1.08 kg ha-1,respectively) and higher weed control index (70.28 %) was observed with application of topramezone + 2,4-D next to recommended weed management practice. The next best treatment was tembotrione + 2,4-D. All the herbicide mixtures resulted in effective and broad spectrum weed control compared to sole application of herbicides. Higher dehydrogenase activity (8.70 μg TPFg-1 soilday-1) was observed in topramezone + 2,4-D.
Growth and yield parameters of maize viz., taller plants (188.90 cm) with higher leaf area (78.74 dm-2), chlorophyll content (48.89), total dry matter production (250.34 g plant-1), hundred grain weight (29.20 g), grain weight per plant (119.49 g), grain yield (5,582 kg ha-1), stover yield (7.32 t ha-1) was recorded in topramezone + 2,4-D next to recommended weed management practice. Gross returns (` 83,730 ha-1), net returns (` 53,769 ha-1) and B:C ratio (2.79) were also significantly higher with topramezone + 2,4-D. However, weedy check was inferior to all other treatments