effect of row spacing and seed rate on yield and yield component of common bean (phaseolus vulgaris l.) cultivars in guilan province

in order to evaluate the effects of row spacing and seed rate on yield and yield component of common bean (phaseolus vulgaris l.) cultivars, a split plot factorial experiment based on randomized complete block design with 3 replications was conducted at second crop research station of rice research institute of iran (rasht) during 2008 and 2009. experimental factors were row spacing in three levels (20, 30 and 40 cm) as main plot and seed rate in three levels (70, 90 and 110 kg.ha-1) and common bean cultivars including khaldar bean short maturation and red kiashahri cultivars as sub plots. the results of the combined analysis of variance showed significant differences between the years, row spacing, cultivars and seed rate in pod and grain yields. the results of mean comparisons showed that maximum pod and grain yields were obtained from the second year (with average of 2689.7 and 1478.8 kg.ha-1), row spacing of 20 cm (with average of 2617.6 and 1396.3 kg.ha-1), khaldar bean short maturation cultivar (with average of 2475.6 and 1398.8 kg.ha-1) and seed rate of 110 kg.ha-1 (with average of 2551.1 and 1414.1 kg.ha-1). results of factor analysis placed the studied traits in three separate groups and plant density per square meter, number of seed per square meter and seed weight per square meter among with the pod and grain yields were in the same group. the use of narrow row spacing (20 cm), more amount of seed (110 kg.ha-1) and khaldar bean short maturation cultivar may increase the pod and grain yields of phaseolus vulgaris cultivars and is recommended for planting common bean in the guilan area.