تعیین فلور علف‌های‌هرز مزارع گندم دیم در استان گلستان و مقایسه آن با مزارع گندم آبی

In the study of weeds in rainfed wheat fields in Golestan province, 52 species of weeds belonging to 18 plant families have been identified. The largest number of species were observed for Poaceae (11 species), Asteraceae (7 species), Chenopodiaceae and Fabaceae (5 species). In terms of relative abundance, Poaceae, Fabaceae, and Polygonaceae families were the most important plant families in rainfed wheat fields in Golestan province respectively. The relative portion of each family from the total relative abundance was 0.281, 0.28 and 0.16, respectively. According to the results of this survey, 79% of the weeds were annual and the rest were perennial. Among the identified weeds, 77% were dicotyledonous and 23% were monocotyledonous. Sweet yellow clover (Melilotus officinalis), common knotgrass (Polygoum aviculare), winter wild oat (Avena ludoviciana), annual rey grass (Lolium rigidum) and wild mustard (Sinapis arvensis) had the highest relative abundance in the province. M. officinalis was the most common weed, which was present in 64% of rainfed wheat fields with an average density of 21 plants per square meter while this weed was observed in 25% of irrigated fields with a density of 4.58 plants per square meter. P. aviculare was observed in 70% of fields with an average density of 9 plants per square meter, while 24% of irrigated wheat fields were infected with this weed, with a density of 2.6 plants per square meter. A. ludoviciana appeared in 49% of fields with an average density of 3.4 plants per square meter. The intensity of this weed infestation in irrigated fields was almost equal to that of rainfed fields. L. rigidum was present in 38% of fields with an average density of 4 plants per square meter, and S. arvensis appeared in 31% of fields with an average density of 1 plant per square meter. In irrigated fields, A. ludoviciana and little seed canary grass (Phalaris minor) were the most important narrow-leaved weeds, while in rainfed fields; A. ludoviciana and L. rigidum were among the most important weeds. P. convolvulus, S. arvensis and M. officinalis had the high importance in irrigated fields, respectively while M. officinalis, P. aviculare and S. arvensis were the most important weeds in rainfed fields respectively. So based on the results of this study, future research in rainfed fields should be aimed at controlling L. rigidum, M. officinalis and P. aviculare in Golestan province.