Effects of rye (Secale cereale L.) and berseem clover (Trifolium alexandrinum L.) cover crops management on yield and yield components of common bean (Phaseolus vulgaris L.) at the presence and absence of weeds

A field experiment was conducted as a factorial based on randomized complete block design with three replications in 2012-2013 growing season at the research farm of the Faculty of Agriculture, Ferdowsi University of Mashhad. Factors included type of cover crops (berseem clover, rye and intercropping of berseem clover+ rye (50:50)), two levels of seeding rate (recommended density: 25 and 190 Kg/ha for berseem clover and rye, respectively and additive density: 1.5 of recommended density) and management method (herbicide+ mulch, mowing+ mulch and mowing). Summer annual weeds like common lambsquarters )Chenopodium album(, barnyard grass )Echinochloa crus-galli( and prostrate pigweed (Amaranthus blitoides( was dominant in this experiment. Among all of the treatments, the highest grain and biological yields were obtained from chemical control (2275.40 and 6089.2 Kg/ha) and hand weeding treatments (2179.60 and 5737.5 Kg/ha), respectively. Except for control treatments, the result of mean comparison showed significant differences in grain and biological yields among other treatments', so that, the highest grain and biological yields were observed in additive density (1332.58 and 3296.7 Kg/ha), intercropping of rye+ berseem clover (1437.83 and 3743 Kg/ha) and herbicide+ Mulch (1965.51 and 4726.7 Kg/ha). Herbicide+ mulch, intercropping of rye+ berseem clover and additive density can be considered as a good choice for reducing weed population and dry weight and increasing yield in common bean (Phaseolus vulgaris L.).