ADJUVANTS TO IMPROVE PHENMEDIPHAM plus DESMEDIPHAM plus ETHOFUMESATE EFFICACY AGAINST WEEDS IN SUGAR -BEET (Beta vulgaris)

The efficacy of reduced (411.5 and 617.2 a.i. ha(-1)) and reconunended (823.0 g a.i. ha(-1)) rates of phenmedipham + desmedipham + ethofumesate on the control of Amaranthus retroflexus, Amaranthus blitoides, Chenopodium album, and Tribulus terrestris in sugar beet field was investigated when they were tankmixed with and without Adigor (0.5% v/v), Anunonium sulphate (2% v/v), Citogate (0.2% v/v), D-Octil (0.3% v/v), Hydro-Max (0.5% v/v), and Volck (0.5% v/v). When the herbicide was applied alone, there was no significant difference between the rates of 617.2 and 823.0 g a.i. ha(-1)for reduction of total weed density and biomass. Significantly, the adjuvants decreased total weed density and biomass. However, there was no significant difference among the performance of adjuvants. The sugar beet root and sucrose yields were increased significantly by increasing herbicide rate as a result of an improvement in weed control. Although herbicide efficacy was influenced in a similar manner by all the adjuvants, the best results were found as follows: root yield was increased up to 9.66% (71.31 Mg ha(-1)) by applying the recommended rate of phenmedipham + desmedipham + ethofumesate plus Adigor compared to weed-free check (64.68 Mg ha(-1)) whereas sucrose yield was increased up to 26.48% (13.21 t ha(-1)) by applying the recommended rate of phenmedipham + desmedipham + ethofumesate plus HydroMax compared to weed-free check (10.45 t ha(-1)). From an economic and ecological standpoint, these two adjuvants can be suggested to optimize the recommended rate of phenmedipham + desmedipham + ethoftunesate in weed management.