نوع مقاله : مقاله پژوهشی
1 دانش آموخته کارشناسی ارشد، گروه زراعت و اصلاح نباتات، واحد یادگار امام خمینی (ره) شهرری، دانشگاه آزاد اسلامی، تهران، ایران
2 دانشیار پژوهش، موسسه تحقیقات گیاه پزشکی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
3 دانشیار، گروه زراعت و اصلاح نباتات، واحد یادگار امام خمینی (ره) شهرری، دانشگاه آزاد اسلامی، تهران، ایران
4 استاد پژوهش، مؤسسه تحقیقات گیاه پزشکی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
عنوان مقاله [English]
In this research, the effects of different levels of nitrogen fertilizer, crop density and variety were investigated on weeds management of wheat with emphasis on winter wild oat (Avena ludoviciana) and flixweed (Descurainia sophia). The experiment was carried out as split plot factorial based on randomized complete block design with three replications at research field of Plant Protection Research Institute, Varamin, Iran, in 2011. Urea fertilizer was considered as main factor and combination of density-variety as sub factor. Results of this study showed that increasing density of Pishtaz and Toos varieties led to reduce in frequency and dry weight of winter wild oat, flixweed and total weed, so that the lowest frequency of winter wild oat (3.55 and 3.66 plant/m2 in Pishtaz and Toos, respectively) was observed at 700 plant/m2 wheat density and it was 3.33 and 3.66 for flixweed in Pishtaz and Toos, respectively. Hovewer, the frequency and dry weight of winter wild oat, flixweed and total weeds increased by increasing the urea fertilizer levels, so that the minimum frequency of total weeds (9.33 plant/m2) was observed to 250 kg/ha urea fertilizer and 700 plant/m2 density of Toos cultivar. Results showed that grain yield decreased in higher densities because of intra-species competition. Due to the reduce in grain yield of Toos variety, the suitable density for this variety was 500 plant/m2, while Pishtaz variety showed a positive reaction to both fertilizer levels and plant density and therefore, the density of 600 plant/m2 was appropriate to control winter wild oat, flixweed and total weeds in this variety. Although the urea fertilizer increased dry weight of winter wild oat, flixweed and total weeds, however 250 and 450 kg/ha urea fertilizer were satisfactory to achieve suitable grain yield in Tous and Pishtaz varieties, respectively. So for weeds control by increasing the wheat density, fertilizer application should also be increased, therefore to use these methods with a view to reducing herbicide, an appropriate balance between these factors must be established.