Effects of Various Weed Management Methods and Crop Density on Weed Control and Yield of Chickpea (Cicer arietinum L.)

To determine the optimum weed management method and plant population density on chickpea yield، a split plot experiment based on RCBD with four replications was carried out at the University of Tehran Research Farm (located in Karaj) during 2010-2011. The Main factor consisted of nine treatments including: 1. Trifluralin pre-plant، 2. Pendimethalin pre-plant، 3. Complete weeding، 4. Imazethapyr post-emergence، 5. Mechanical weeding، 6. Imazethapyr pre-emergence، 7. Pyridate along with mechanical weeding، 8. Pyridate post-emergence، 9. Control (no weeding) and sub factor included of three crop densities of 35، 45 and 55 plants/m2. The predominant weeds were Chenopodium album L.، Amaranthus retroflexus L. and Amaranthus blitoides L. Results revealed that weed management had a significant effect on weed population and dry mass reduction. At the end of the growth period after hand weeding treatment، Pyridate + mechanical control، pre-emergence Imazethapyr and pendimethalin were the most effective treatments based on weed dry mass reduction، but due to weed population decline at this time، after hand weeding treatment، pendimethalin was the most effective and produced the highest chickpea grain yield. Chickpea population densities of 55 and 45 plants/m2 produced the highest grain yield and simultaneously reduced the weed population and dry mass as compared with 35 plants per m2، significantly. Therefore، application of both pendimethalin and use of 45 chickpea plants per m2 were the effective weed control method and produce a higher grain yield at a similar condition to this experiment.