Efecto de la dosis de siembra en los rendimientos de tres cultivares de frejol (Phaseolus vulgaris L.) para verde.

The purpose of this thesis was to evaluate the effect of different sowing rates of three bean (Phaseolus vulgaris L.) genotypes, on yield per area of green and dry stage, and on yield per plant and its components. Fifteen treatments from a factorial combination of three genotypes (Choshuenco, Apolo and Cristal Bayo) and five seeding rates (80, 120, 160, 200, 240 kg/ha) were used; each treatment replicated three times. The parameters evaluated were: number of plants per area (density of plants); number of harvests and yield at the green stage; yield at the dry stage and analysis of the components of yield. Also, the number of plants that arrived to the final stage and percentage of final establishment of plants on green and dry stage. The results were analized by Fisher's analysis of variance, applying Tukey's multiple comparison test as well as regression analysis. Simple correlations were also calculated among the yield and its components, and among the number of plants that arrived to final stage (green stage-dry stage), the percentage of final establishment (green stage-dry stage), first and second harvest and its total yield (green stage-dry stage). It can be concluded that: Genotype Apolo obtained the highest yield per area on green stage. The highest yield per plant was obtained by Cristal Bayo and Apolo. The rate of 200 kg/ha gave the highest yields per area on green stage for the three genotypes. In relation to yield at dry stage 80 kg/ha it was not different from other rates. Yield per plant presented a positive association with the number of pods per plant and number of seeds per pod, while it had no association with the seed average weight. There was neither association between the number of pods per plant with the number of seeds per pod, nor with the seed average weight. The number of seeds per pod was negatively associated with the seed average weight. When the rate of sowing was increased, more plants arrived to the green and dry stage; genotypes Choshuenco and Cristal Bayo presented the highest values for this parameter. Percentage of final establishment did not present differences for the different rates (neither green nor dry stages). Cristal Bayo obtained the highest value for this parameter. Yield for green stage depended on the number of plants that arrived to the final stage and on the sowing rate.