The effect of weed interference on shoot and root growth and harvest index in chickpea

To evaluate the effect of different weeds interference periods on shoot and root growth and harvest index of chickpea, an experiment was conducted at two environments using randomized compelete block design with four replications. Experiment environments were Tabriz and Kermanshah at first and second year, respectively. In each experiment, twelve treatments consisted of six initial weed-free periods (in which, plots were kept free of weeds for 0, 12, 24, 36, 48 and 60 days after crop emergence (DAE), and then weeds were allowed to grow until harvest) and six initial weed-infested periods (in which, weeds were allowed to grow for 0, 12, 24, 36, 48 and 60 DAE, after which the plots were kept free of weeds until harvest). The results indicated that, with increase of weed-infested and reduction of weed-free duration, the length and weight of chickpea shoots and roots significantly reduced as compared to control (weed free for all of the growing season). The reductions were more for roots than shoots. Consequently, shoot length: root length and shoot weight: root weight ratios increased. Moreover, reduction was more for weight of shoots and roots as compared to their length. Harvest index was also significantly decreased with increasing of weed-infested duration and decreasing of weed-free period. This reduction was 42.8% for full season weedy treatment as compared to control.: