The effect of main crop harvesting time on Rice-ratoon and Berseem clover (Trifolium alexanderinum L.) yield as intercropping system

To determine the effect of main crop harvesting time on rice ratoon and berseem clover yield as intercropping system, the experiment was conducted out as split plot in randomized complete block design with three replications in Northern Iran at 2010. Main crop harvesting time of rice has been chosen as main plot at four levels; 19 and 26 August, and 2 and 9 September. The kind of cultivation has been also chosen as sub-plot at three levels; berseem clover cultivation, ratooning, and intercropping berseem clover with rice ratoon. The results showed that the total number of tillers and effective tillers per hill, the total number of spikelet per panicle and percentage of filled spikelet were significantly decreased by delaying harvesting time. The maximum grain yield and harvesting index were attained by earlier harvesting time at 19 and 26 August, respectively. Grain yield of rice ratoon by only ratooning is also more 3.4% than intercropping clover-ratoon. The minimum wet hay yield of berseem clover was obtained by harvesting time at 26 August. The maximum total land equivalent ratio (LER) was also obtained by harvesting time at 9 September. It can be concluded that intercropping berseem clover with rice ratoon and earlier harvesting time at 19 and 26 August is suitable to attain maximum yield of rice ratoon grain and berseem clover hay.