Tolerance of wild oats biotypes to different oat killers and their impact on some agronomic and physiological traits of wheat

Field experiment was initiated at Agricultural Research Farm; NWFP Agricultural University, Peshawar during Rabi 2004-05 to figure out the tolerance of different wild oats biotypes to herbicides. The experiment was laid out in randomized complete block design under a split-plot arrangement, with three replications. The experiment comprised of four wild oats biotypes assigned to the main plots, while 3 herbicides and a weedy check (Sencor, isoproturon and Affinity) were kept in sub-plots. The Ghaznavi-98 variety of wheat in a sub-plot size of 5x 1m2 was used. The data were recorded on tiller plant-1, wheat plant height at maturity (cm), wheat spike length (cm), grain yield (t ha-1) and the protein content (%) in grain. The statistical analyses of data exhibited non-significant differences for tolerance of biotypes to herbicides in all the morphological and agronomic traits, while herbicides and their interaction with biotypes were significant for all the traits examined except wheat plant height and protein content % in grain. As a consequence of phytotoxic effect on weeds, the herbicides increased grain yield and yield components. The herbicide Affinity out yielded rest of the herbicides. In general, the highest grain yield was harvested in Affinity treated plots across all the wild oats biotypes. The interaction of biotypes with the herbicides exhibited a differential competitive ability or tolerance to different herbicides. It is thus recommended that judicious thinking is desired to control different biotypes infesting farmers' fields, because wild oat (Avena fatua L.) is one of he most troublesome weeds in the weed community. The Pakistani prairies are a semiarid region prone to soil erosion, and appears to be an appropriate site to adopt conservation tillage practices. Due to the environmental concerns and the development of herbicide resistance, it would be desirable to integrate all aspects of crop management systems, rather than solely rely on herbicides, to manage wild oat problems.