Effect of Spring Seeding and Short-day Treatment on Harvest Time and Yields of Soybean Cultivar ‘Tanbaguro’ as Green Soybean in the North of Okayama Prefecture

Abstract

Seeding time and short-day treatment in an early period of flowering of ‘Tanbaguro’, a late bearing soybean cultivar, were evaluated for summer harvesting. When the plant was seeded between March 1 and 15, 1998, it could be harvested in early July. The total yield was higher as the seeding time was earlier. However, when it was seeded on or after March 25, it could not be harvested in July. In 2001, the harvest time was mid-August even when the plant was seeded in early March, probably because the temperature before the flowering period was lower in 2001 than in 1998. However, when short-day treatment was performed for 5 days in the early flowering period, the pods enlarged steadily, and the plant could be harvested in early July. As the short-day treatment period was prolonged, harvesting could be started earlier, but the yield decreased.