Investigating the weeds interference with yield and yield components of dryland lentil (Lens culinaris L.) under field conditions

In order to investigate the effect of weeds on lentil, an experiment was conducted on a farm located in the Razi university, Kermanshah. The levels of weed infestation in different parts of the farm were classified into six classes from low to high. Sampling was performed using a 1m2 quadrat during the lentil growth season. The results showed that at the weed infestation level of greater than 50% (highest infestation level), the rate of reduction in the seed number, seed weight, pod number, pod weight, thousand seed weight were 79.5%, 81.7%, 80.1%, 85.4% and 13.5% respectively in comparison with the weed infestation level of less than 10% (minimum infestation level). The results of stepwise regression models showed that the presence of weeds during the first (30 days after emergence) and fourth sampling stage (60 days after emergence) had a significant effect on different traits of lentil. In the first sampling stage, Convolvulus arvensis and Galium aparine were detected as the most important weeds with a significant negative coefficient on the number of pods (-12.3 and -11.4, respectively), pod weight (-0.21 and -0.19, respectively), seed number (-12.25 and -12.20, respectively) and seed weight (-0.62 and -0.59, respectively). In the fourth stage of sampling, G. aparine and Lactuca serriola with a significant negative coefficient; number of pods (-11.65 and -2.23, respectively), the seed number (-12.74 and -2.23, respectively) and seed weight (-0.62 and -0.11) were the most important weeds of the field.