A field experiment was conducted at the research farm of the University of Tehran to evaluate the effect of cover crops and herbicide (nicosulfuron) dosage on corn (Zea mays L.) productivity. Cover crops suppressed weed biomass and density during the fallow period; however, there was no significant effect on weed biomass or weed density in the subsequent corn crop. A mixture of cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth.) was the most weed-suppressive cover in the fallow period. Nicosulfuron applied at different amounts suppressed weed biomass and density in corn when compared with weedy plots. Application of 40 g ai ha−1 of nicosulfuron was as effective on weed control as the recommended application. Cover crops did not affect corn growth; however, corn yield improved with herbicide application.

中文翻译：

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覆盖作物和烟嘧磺隆用量对玉米作物杂草控制和生产力的作用

在德黑兰大学的研究农场进行了一项田间试验，以评估覆盖作物和除草剂（烟嘧磺隆）剂量对玉米的影响（玉米L.) 生产力。覆盖作物在休耕期抑制杂草生物量和密度；然而，对随后的玉米作物的杂草生物量或杂草密度没有显着影响。谷物黑麦的混合物（黑麦L.) 和毛紫云英 (紫花苜蓿Roth.) 是休耕期最能抑制杂草的覆盖物。与杂草田相比，施用不同量的烟嘧磺隆抑制了玉米中的杂草生物量和密度。应用 40 g ai ha-1烟嘧磺隆对杂草的控制与推荐的应用一样有效。覆盖作物不影响玉米生长；然而，玉米产量随着除草剂的应用而提高。