ارزیابی شاخص‌های اکولوژیکی تنوع علف‌های هرز شوید تحت تأثیر تاریخ کاشت و مرحله کنترل علف هرز

In order to study the effects of planting date and weed control at different stages of dill on diversity indices for weeds, an experiment was conducted at Shirvan Agricultural Research Station during growing season of 2011-2012. Four planting dates such as early January, early February, early March, early April and three weed control stages including emergence of true leaf, branching and umbel formation of dill. Diversity of weeds was evaluated by Manhinick, Margalef, Sympson and Shannon indices. The results showed that the planting date was affected weed diversity and weeds were differently responded to the planting date. So, the highest diversities for Manhinick, Margalef, Sympson and Shannon indices were calculated with early February (2.12), early March (3.5), early March (0.94) and early April (1.07), respectively. Based on the results, as planting date and weed control stage affected the diversity indices of weed in dill field, could be used these two agronomic approaches for sustainable production the medicinal plant.