Comparative Efficacy of Tembotrione (420 SC) and their Combination for Diverse Weed Flora in Wide Spaced Sugarcane (Saccharum officinarum L.) Provides Sustainable Weed Management

Widely spaced sugarcane, which is becoming progressively more popular in tropical India to enable mechanization is seriously threatened by weed invasion. Compatibility of tembotrione 420 SC as a tank mix in sugarcane with surfactant (isoxadifen-ethyl), atrazine, metribuzin, and ethoxysulfuron, as well as the residual effects on subsequent crops, were investigated in two consecutive years during the special season June–September in 2015-16 and 2016-17. Application of PoE tembotrione at 120.75 g a.i/ha + surfactant at 1000 ml/ha + metribuzine at 1050 g a.i/ha significantly reduced the weed density and biomass of grasses, broad leaved weeds and this was statistically comparable with tembotrione at 120.75 g a.i/ha + surfactant at 1000 ml/ha + atrazine at 500 g a.i/ha. Herbicidal combination of PoE tembotrione at 120.75 g a.i/ha + surfactant at 1000 ml/ha + metribuzine at 1050 g a.i/ha was recorded lesser dominant grassy and broad leaved weeds viz., Sitaria verticillata (L.), Dactyloctenium aegyptium Beauv., Dinebra retroflexa (Vahl) Panzer, Trianthema portulacastrum (L.), Portulaca oleracea (L.), Digera arvensis (Forsk), Datura fastuosa (L.) and Cleome gynandra (L.) with higher WCE (83.16% & 87.43% at 30 DAA) and cane yield (134.1 t/ha & 136.2 t/ha) in 2015-16 and 2016-17, respectively which was comparable with tembotrione at 120.75 g a.i/ha + surfactant at 1000 ml/ha + atrazine at 500 g a.i/ha of 129.8 t/ha in 2015-16 and 132.1 t/ha in 2016-17, respectively. Yield reduction in the untreated control plots of 46.46% in 2015-16 and 45.57% in 2016-17, respectively. Finally, the combination of tembotrione at 120.75 g a.i/ha + surfactant at 1000 ml/ha + metribuzine at 1050 g a.i/ha at 15 and 30 DAA can maintain a reasonable level of total weed density and dry weight while increasing sugarcane productivity without posing a phytotoxicity risk to either the primary crop or the sunflower that follows.