Effect of different dates of cover crops planting on weed control, accumulation and remobilization of photosynthesis material in corn)Zea mays L.)

A field experiment was conducted in 2011 to determine the effect of different cover crop planting data on weed control, accumulation and remobilization of photosynthetic material in corn. The cover crops included which either planted simultaneous with corn or soybean, fenugreek and cowpea 21 days after corn planting. The results showed that the second date of cowpea planting and first date of soybean reduced dry weight of weed (97% and 93%), respectively. The highest grain yield of corn was related to weed control (11853.3 kg.h-1) and second date of cowpea planting (11447.4 kg.h-1), and the lowest one was showed in sole corn with weed interference (5246.1 kg.h-1). In addition, sole corn treatment with weed control (65.8 gr.plant-1) has the highest and first date of cowpea planting and sole corn without weed control have the lowest dry matter remobilization (17.29 and 6.28 gr.plant-1 respectively). The highest remobilization efficiency was 19.57% and 19.07% and remobilization contribution was 31.17% and 31.28% in sole corn with weed control and second date of cowpea planting, respectively.