Effects of Sowing Date and Plant Density on Yield and its Components and Percentage of Seed Protein in Cultivars of Red Bean (phaseolus vulgaris L.)

 An experiment was conducted to study the effects of some agro-technical factors (plant density, sowing date and cultivar) on qualitative and quantitative yield in two cultivars of Red bean (Phaseolus vulgar cv. Saiad, Naze) under the climatic conditions of Zanjan. The experiment was executed as split-plot factorial based on randomized complete block design with three replication. Sowing date was devoted to the main plots with three levels (5 May, 22 May and 10 June) and cultivar with two levels (Saiad and Naz) and plant density with three levels (15, 22 and 45 plant per m2) were factorially devoted to the sup plots. Analysis of variance showed that components of seed yield (number of pods per plant, number of branches per plant, number of seed per pod, number of seed per plant ), biological yield, harvest index and percentage of seed protein were significantly affected by cultivar (P < 0.01). Cultivar did not have any significant effect on seed yield. The effect of sowing date was significant on seed yield, biological yield, harvest index and components of seed yield and weight of one hundred seeds (P < 0.01). The effect of plant density on percentage of seed protein and harvest index were non-significant, but other characteristics were significantly affected by density (P < 0.01). The highest number of pod per plant, number of branches, number of seed per pod, number of seed per plant, biological yield were related to cultivar Naz and the highest harvest index and percentage of seed protein were related to cultivar Saiad. Delayed planting increased seed and biological yield. The greatest percentage of seed protein was obtained from the third planting date. The density of 45 plant/m2 was significantly superior to the two other densities regarding seed and biological yield. There was not a significant difference between 15 plants/m2, 22 plant/m2 and 45 plant/m2 in percentage of seed protein. Cultivar Saiad at the density of 45 plant/m2 and sowing date of May 25th resulted in the highest seed yield. Cultivar Saiad at the density of 45 plant/m2 and sowing date of June 10th resulted in the highest percentage of seed protein.