Tolerance of Different Wild Oats Biotypes to Different Oat Killers and Their Impact on Wheat

摘要

The ecological starting point for crop health requires knowledge of what is in the soil (microbes, insects, weed seeds, etc.), methods to prevent herbicides resistance build up in the crop, and knowledge to maximize the plants ability to defend itself. The focus of most current crop production practices is weed control with little effort applied by herbicides. Cropping practices that degrade soil and limit genetic diversity contribute to increasing weed populations. A field experiment was initiated at Malkandher Research Farm, NWFP (North West Frontier Province) Agricultural University, Peshawar during Rabi 2005-2006 to figure out the tolerance of different wild oats (noxious weed) 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 along with a weedy check (Sencor, Isoproturon, Affinity and Weedy check treatment) were kept in sub-plots. The Ghaznavi-98 variety of wheat in a sub-plot size of 5 x 1m~2 was planted on November 13, 2005. The data were recorded on tillers plant~(-1), wheat spikes m~(-2), number of grains spike~(-1), 1,000 grain weight (g), biological yield (t ha~(-1)), grain yield (t ha~(-1)) and the pro.tein 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. 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 the most troublesome weeds in the weed community. ThePakistani 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.