effects of cover crops residue on weed control, physiological indices, yield and yield components of potato (solanum tuberosum l.)

the aim of this study was to investigate the effects of winter crops residues on weed control, physiological indices, yield and yield components of potato. an experiment was carried out at the research farm of colleg of agricultural of bu-ali sina university in 2009. the experiment was a randomized complete block design with three replications. residues of rye, oilseed rape, triticale, barley, chemical weed control and control (no cover crop and no chemical control) were the experimental treatments. the results showed that winter cereals residues produced more biomass than winter oilseed rape residues. cover crop treatments showed significant different in weed control of potato at 3 times (15, 45 and 75 days after germination) in compare to control treatment. residues of oilseed rape and rye had the most inhibition affects on summer weeds. these treatments, decreased average biomass of weeds by 61 and 57 percent, respectively, in compare to control. oilseed rape and rye residues in compare to control, reduced weeds density in potato by 36 and 35 percent, respectively. residues of oilseed rape and rye improved physiological indices of potato. a significant correlations of weeds plant population, weeds dry matter, physiological indices and average tuber weight of potato with potato yield was detected. the treatments of oilseed rape and rye in compare to control, increased tuber yield of potato by 54 and 50 percent, respectively. these treatments, increased the average tuber weight by 74 and 38 percent, respectively, in compare to control,.