Study the Effect of Four Cover Crops on the Weed Management in Plum (Prunus domestic) Orchards in Urmia

To investigate the effects of winter cover crops and their management on the density and dry matter of weeds in plum orchards, an experiment was conducted during 2014-2015 in Urmia. The experiment was performed in the randomized complete block design with spilt plot arrangement. Four cover crops in main plots included: ryegrass (Secale cereale L.), barley (Hordeum vulgare L.), oilseed (Brassica napus L.) and clover (Trifolium resupintum L.) and management methods including cutting- off cover crops and using rotivator in sub –plots were experimental treatments. According to the results, the highest and lowest dry matter of cover crops belonged to ryegrass (275 gr.m-2) and clover (97 gr.m-2) and the highest and lowest leaf area index were observed in ryegrass (3.5) and clover (1.4) respectively. Comparison of cutting- off cover crop and rotivator revealed that rotivator’s effect on weed density (%67) and dry matter (%31) is more effective than cutting-off cover crops. Totally, results of this study revealed that ryegrass and barley planting as cover crops, along with using rotivator, is the best recommended method for weed control in Urmia plum orchards.