Can weed composition and diversity support chickpea yield? A case study on dryland fields from western Iran

Abstract

Abstract To evaluate the impacts of weed communities on chickpea yield (Cicer arietinum L.), an on-farm survey was conducted with a sampling from 85 dryland chickpea fields in a rural district, western Iran. The results showed that chickpea yield tended to decrease with increasing weed density and canopy cover as indicated by a polynomial response. Increasing weed density from 0 to 50 plant m-2 reduced the chickpea yield by 36.73% at the four to seven-leaf stage of chickpea. In addition, increases canopy cover from 0 to 55% caused chickpea yield loses by 41.70 g m-2 at the early podding stage of chickpea. Weed diversity and evenness had a positive effect on chickpea yield. Wild safflower (Carthamus oxyacantha M. Bieb.) and chicory (Cichorium intybus L.) were the most predominant weeds with a significant negative correlation with chickpea yield, weed evenness and diversity. Some weeds, such as licorice (Glycyrrhiza glabra L.) had a negative correlation with chicory and wild safflower and a positive correlation with weed diversity and evenness. In addition, there was a positive relationship between density and canopy cover of licorice and chickpea yield, weed diversity and evenness.