In order to evaluation the effect of planting date, method and date of weed control on weed population and cumin yield an experimental was conducted in the experimental research field, Faculty of Agriculture, Shirvan University, during 2010. Treatments included planting date (30 December, 20 January and 30 February), weeding date (first true leaf, start of branching and beginning of flowering stages) and weed control methods (hand weeding, fire treatment and control). The results showed that there were significant differences between different sowing date, as the highest yield was in 30 December and the lowest was in 30 February. It showed that there were significant differences between hand weeding, control and fire treatments. The highest and lowest yield of cumin seed was obtained in hand weeding and control methods respectively. There were no significant differences in start of branching stage, beginning of flowering stages and first true leaf stage in different times of weed control but the highest cumin seed obtained in start of branching. There were significant differences in number of weeds between different sowing dates. The highest number of weeds was obtained in 11 December. Also, the lowest number of weeds was obtained in 20 January. There were significant differences in height of weeds between different sowing dates. The highest and lowest height of weeds was obtained in 11 December and 29 February respectively. Total numbers of weed species were 13 from 10 different plant families. Number of dicotyledons species (12) were more than monocotyledons (1) [1, 2].

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