Triketone Derivates of Hydroxyl Phenyl Pyruvate Dioxygenase (HPPD) as Potential Herbicides against Diverse Weed Flora in Maize: Efficacy, Phyto-toxicity, Soil Residual Toxicity Impact on Succeeding Sunflower

Abstract

Aim: Field experiments were conducted for two years during 2016-17 to 2017-18 to evaluate the compatibility of tembotrione 420 SC (Laudis) on maize and its residual effect on succeeding crop. Methodology: Randomized complete block design with three replications were used. TNAU maize hybrid CO6 variety was sown with spacing of 60cm x 30cm. Seven weed control treatments were combined with various herbicide dosages followed by tembotrione (420 SC), 2,4-dimethyl amine salt (58% SL), atrazine (50% WP) and surfactant (isoxadifen-ethyl) were sprayed. Results: POE tembotrione at 120 g a.i.ha-1 + surfactant at 1000 ml + atrazine at 500 g a.i.ha-1 applied at 2-4 leaf stage provided satisfactory control of all types of weeds (grassy weeds, broad-leaved weeds and sedges) in maize without causing any crop phyto-toxicity on maize, which led to a higher grain yield and improved profitability. It was significantly controlled the dominant grassy and broad-leaved weeds which are Setaria verticillata (L.), Dactyloctenium aegyptium (L.), Panicum repens (L.), Cyperus rotundus (L.), Trianthema portulacastrum (L.) and Cleome gynandra (L.) as compared to the remaining herbicidal treatment. Laudis with different herbicide combinations had no phyto-toxicity on maize and it had no residual toxicity effect in sunflower subsequent crop. Interpretation: Compatibility of tembotrione (420 SC)  at 120 g a.i.ha-1 + surfactant at 1000 ml + atrazine (50% WP)  at 500 g a.i.ha-1 at 20 and 40 DAHS can maintain the total weed density and dry weight at a reasonable level and increase the productivity of rabi maize.