Evaluation of herbicides for weed control in irrigated wheat in Saudi Arabia

Abstract

In wheat fields, irrigated with treated sewage water, the performance of six herbicides: bromoxynil/MCPA; bentazon/ dichlorprop; diclofop-methyl; tralkoxydim; pendimethalin and bromophenoxim; and some their combinations were assessed at two different locations around the city of Riyadh. The common weeds include: Lolium spp.; Phalaris spp.; Avena spp.; Malva spp.; Chenopodium spp. and others. The best weed control treatments were: bentazon/dichlorprop followed by bromoxynil/MCPA for the broad-leaved, and diclofop-methyl followed by tralkoxydim for the grassy weeds. The combinations of bromoxynil/MCPA with either pendimethalin or tralkoxydim were far more effective against the broad-leaved weeds, and significantly improved the wheat growth and yield, compared with the single treatments. However, bromoxynil/MCPA combination with diclofop-methyl was less effective against the grassy and broad-leaved weeds than each of them. Bromophenoxim showed an effective control of the whole weeds, with appreciable improvement in the wheat growth and yield.

Effect of Pendimethalin, Trifluralin and Terbutryn on Lolium multiflorum growing with barley during pre-emergence stage

“…Trifluralin undergoes an extremely complex fate in the environment and is transiently transformed into many different products as it degrades, ultimately being incorporated into soil-bound residues or converted to carbon dioxide (mineralized). Among the more unusual behaviors of trifluralin is inactivation in wet soils (Tag-ElDin et al, 1989). This has been linked to transformation of the herbicide by reduced soil minerals, which in turn had been previously reduced by soil microorganisms as electron acceptors in the absence of oxygen.…”