GROWTH OF BEAN ACCESSIONS AT VARIOUS TEMPERATURES

Abstract

Growth and rates of photosynthesis of two accessions and two cultivars (Great Northern 1140 and Sutter Pink) of bean (Phaseolus vulgaris L.) were compared at 10, 15, and 23 °C in a controlled environment cabinet. The leaf area, dry matter, and rate of total apparent photosynthesis of one of the accessions was significantly higher after growth for 13 days at 10 °C than that of the commercial cultivars. This advantage was not maintained at 23 °C. In another experiment, growth of the same four cultivars was compared at light/dark temperatures of 10/10, 15/12, and 23/18 °C. The two accessions established a higher leaf area and accumulated more dry matter at the cooler temperatures than the commercial cultivars, but lost this advantage at the highest temperatures. In a field trial, the accessions had a similar rapid early growth but fell behind later in the season. Ideally, a bean cultivar for the Canadian prairie should incorporate the accession’s ability for rapid growth and leaf expansion at cool temperatures with a growth rate during mid-summer comparable to that of Great Northern 1140.