Ontogeny and Yield Response of Common and Tepary Beans to Temperature

Abstract

AbstractTemperature affects crop development and yield. In this study the effect of temperature on emergence, vegetative development, and yield of common bean (Phaseolus vulgaris L.) and tepary bean (P. acutifolius A. Gray) was compared. In the growth chamber nine common bean accessions were evaluated for emergence response over planting depths of 25, 50 and 75 mm, and at constant temperatures of 15,20,25,30, and 35 °C. The three depths had no significant effect on emergence between 20 and 30 °C, but at 15 and 35°C the increased depth significantly delayed emergence. The most rapid germination and emergence occurred at 30 °C under these controlled conditions. In the field emergence of the same common bean accessions was compared to tepary bean; tepary bean emerged about 1.5 d earlier than common bean at soil temperatures of 18 to 28 °C. The effect of temperature on vegetative development was evaluated by a linear heat unit system that measured base temperature (Tbase) and heat units to flowering. Under field conditions common bean had an average base temperature (Tbase) lower than tepary bean, and required more heat units to flower. Genotypic differences for base temperatures and heat unit requirements existed among accessions within both species. Temperature strongly affected the yields of both species when grown at Riverside, CA, on an Arlington fine sandy loam (coarse‐loamy, mixed, thermic Haplic Durixeralf). Tepary bean produced higher yields than common bean under hot summer conditions, but lower yields under early spring conditions.