Determination of different cover crop efficiency for weed control in citrus orchard

In order to determine efficiency of different cover crops in terms of weed control in citrus orchard, an experiment was conducted during 2009 based randomized complete block design with 7 treatment and 3 replications at Komdarreh region, Amol, Mazandaran province. Legumes cover crops including common bean, white bean, pinto bean, red bean, cowpea, mung bean, lentil and common pea were the treatments. Results showed that all mentioned cover crops were significantly different in terms of all studied parameters expect for canopy diameter. In terms of dry weight, white bean had the highest amount and the lowest rate was belonged to lentil and red bean. Maximum dry matter of weeds (116.77 gr m-2) recorded in common pea while mung bean had the lowest amount (19.83 gr m-2). Cover crop/weed index (CCWI) of two cover crop plants i.e. white bean and mung bean by 6.41 and 5.60 had the most effectiveness for controlling of weeds and classified in outstanding weed control class. Cowpea with CCWI value of 3.05 classified in adequate weed control class, however, common pea, lentil and red bean classified in poor class. Generally in terms of biomass production and weed control, common bean, mung bean and cowpea are probably most suitable cover crops and easy to grow and to manage.