Effects of maximum temperature and age on flowering and seed production in three bean varieties

Statistical studies on five bean varieties, California Red, Sutter Pink, Pinto, Red Kidney, and Small White, planted at 2-week intervals from late May to late July over a four-year period indicated that yields increased up to mid-June, remained high through mid-July, and then declined in late July for four of the five varieties. The exception was Small White which did not mature in the mid-July planting some years and never in late-July plantings. Significant differences were obtained in varietal yields.

Correlation studies of data from tagged flowers on three varieties over a three-year period were made.

Significant positive correlations were obtained between per cent set and beans per pod in all varieties.

Significant negative correlations were obtained between age of plants and per cent set, and age of plants and beans per pod in all varieties.

Significant negative correlations were obtained between per cent set and maximum temperatures the day before, the day of, and the day after bloom in Small White and Sutter Pink. In California Red these correlations were too low to be significant.

The negative correlations between maximum temperature and beans per pod were smaller than between maximum temperature and per cent set, and only in Sutter Pink were they significant. Beans per pod in California Red were not affected by temperature.

California Red gave the highest yields, highest per cent set and highest beans per pod. In all three measures Sutter Pink ranked second and Small White third.

Advancing age of plants was more effective in reducing per cent set than were increasing temperatures.