Specific Weed Tolerance of Wheat (Triticum aestivum L.) Varieties - A Key to Non-chemical Weed Control

Six wheat varieties representing different genotypes were tested under exposed and protected conditions in a three year herbicide provocation field trial at Nagygombos, Hungary. Three types of herbicide treatments (fluroxipir, bromoxynil and dicamba ai.) were applied in comparison with untreated and mechanical treated controls. Weed populations were sorted into two major groups according to the level of their occurrence. The result of experimental treatments were evaluated and weed tolerance of varieties was determined. The magnitude of weed populations has shown significant differences. All weed control treatments, including chemical and mechanical applications, had an influence on weed development. Herbicide treatments had about fifty per cent, while mechanical applications had a nearly hundred per cent effect concerning weed reduction. The latter can be considered as a level of total weed extinction. High weed canopies were observed in the case of untreated controls only. Wheat cultivars have shown a variety specific yield response. The results obtained suggest varietal differences concerning weed tolerance. The extent of yield losses between wheat cultivars ranged from 4 to 18 per cent of grain yield. In the trial Martonvásári 19 and Martonvásári 21 wheat varieties were proven to have the best weed tolerance abilities.