Efficacy of Clodinafop Against Isoproturon-Resistant Phalaris minor in Relation to Wheat Cultivars and Spacing

Wheat cultivar PBW-343 caused maximum suppression in dry matter of P. minor by 30.7 and 48.5% over WH-542 and PDW-233, respectively, due to greater competition of fered by more number of tillers and resulted in 6.9 and 37.5% higher grain yield over WH-542 and PDW-233, respectively. Narrower row spacing of 15 cm registered lower dry matter of P minor by 18.1% due to higher number of tillers and resulted in increase in mean yield to the tune of 15.7% than normal spacing of 22.5 cm. The study further revealed that PBW-343 at closer spacing exerted more smothering effect and caused 44.5 and 34.8% reduction in dry matter of P. minor when compared with cultivar WH-542 at normal and closer spacing. The studies also indicated that dry matter of P. minor in cultivar PBW-343 when treated with clodinafop 45 g ha⁻¹ was statistically same when it was compared with cultivar WH-542 and PDW-233 when these were treated with clodinafop at 60 g ha⁻¹. Wheat cultivars PBW-343 and WH-542 treated with clodinafop 45 g ha⁻¹ gave significantly more grain yield than durum wheat when it was treated with clodinafop 60 g ha⁻¹. It was interesting that use of cultivar PBW-343 in association with clodinafop 45 g ha⁻¹ and closer spacing of 15 cm gave significantly more grain yield when it was sown at nomlal spacing of 22.5 cm alongwith higher dose of clodinafop 60 g ha⁻¹. Further, the study revealed that bread wheat cultivars PBW-343 and WH-542 at closer spacing when treated with clodinafop either at 45 g ha⁻¹ or 60 g ha⁻¹ gave statistically same yield, however, in case of durum wheat PDW-233, the grain yield significantly decreased at closer spacing when treated with clodinafop at 45 g ha⁻¹ in comparison to 60 g ha⁻¹.