Effect of temperature, relative humidity and drip irrigation on productivity of common bean (Phaseolus vulgaris L.) in the Yaqui Valley, Sonora, Mexico

In southern Sonora, Mexico, the temperature has maintained a tendency to increase 0.2°C every spring season, which poses a risk for bean production, since high temperatures might occur during the critical periods of flowering and grain-filling that define the final grain yield. The objective was to determine the impact of temperature and relative humidity on bean grain yield and quality in two commercial fields (B-2110 and B-2228) sown in two dates (March 9 and 25, and 3 and 27, respectively) with cultivar Pinto Saltillo, in the Yaqui Valley, Sonora under drip irrigation. The fruiting period was evaluated in relation to temperature, relative humidity and drip irrigation sheets. Meteorological data were obtained from digital sensors installed within the crop, in addition to the meteorological stations closest to each field. The analysis of variance was highly significant for number of pods with grain, number of grains per pod, specific grain weight, and grain yield ha^-1. Bean grain yield varied from 1,204 to 3,271 kg ha^-1; the highest yield was obtained in field B-2110 on the first date, where a total water sheet of 50.4 cm was applied with a 12.1 day interval between 8 irrigations; while the lowest yield was obtained in B-2228 on the second date where a total water sheet of 59.60 cm was applied with a 5.6 day interval between 14 irrigations. The number of continuous hours and days with temperature greater than 33°C and relative humidity greater than 90% during the fruitful stage of the crop, were related to the greatest number of pods without grain and the lowest grain weight, with a significant reduction in the quality for consumption. The consumption quality of the grain was mainly affected in the late sowing dates, where losses of 32.6 to 48.7% were obtained in fields B-2110 and B-2228, respectively.