بهبود رشد کنجد در رقابت با علف‌های هرز در حضور قارچ مایکوریزا

The presence of weeds in sesame fields reduces the quantitative and qualitative yield. Effective strategies to increase crop tolerance against weeds are important. Inoculation of wheat root with Arbuscular mycorrhiza a fungi can be effective in reducing weed-damage effects on sesame fields. To investigate the effects of mycorrhizal fungus on competitive relations between sesame (Sesamum indicum L.) and weeds, two separated factorial experiments based on a completely randomized design were carried out at greenhouse conditions in shahriyar, during 2022-2023. The factors of the 1st experiment were sesame and six weed species and two levels of mycorrhiza inoculation (with and without fungus) and that of the 2nd experiment were pure stand of sesame, red root pig weed and Common lambsquarters and mixed cropping of sesame with red root pig weed and sesame with Common lambsquarters, and two levels of mycorrhiza inoculation (with and without fungus). In the 1stexperiment, mycorrhizal Colonization of shepherd's purse (Capsella bursa-pastoris), Black nightshade (Solanum nigrum), Common Purslane ( Portulaca oleracea), Barnyardgrass (Echinochloa crus-galli) and sesame were 10, 50.70, 80 and 95 percentage, respectively and that of red root pig weed (Amaranthus retroflexus ) and Common lambsquarters (Chenopodium album) were 5 and 4 percentage, respectively. In the 2nd experiment red root pig weed and Common lambsquarters competition in non-fungus inoculated treatment reduced sesame dry weight by 41 % and 62%, respectively. In the presence of fungus, sesame dry weight in competition red root pig weed and Common lambsquarters, increased by 45% and 49%, respectively. In pure stand of sesame in the presence of fungus, sesame yield was 3.65 g/plant, which increased by 55 % in comparison with non-application of fungus. The results of this research indicate that if the dominant weeds in the secam fields, are non-mycorrhizal, is negative, the application of mycorrhizal fungi can reduce the damage of those weeds.