Research notes: Variation in the photoperiodic response to flowering in soybean
Soybean cultivars representing each of the 10 U.S. Maturity Groups (MGS) (00 to VIII) were screened for the photoperiodic response to flowering from March, 1974 to June, 1974; another set was screened from October, 1974 to January, 1975 using natural daylength in the field as the short-day treatment. In another distant field artificial light was used to extend the natural daylength to 16 hr which represented the long-day treatment. In the March screening, l,898 cultivars were screened while in October, 1,547 cultivars were screened.