Frost tolerance

Frost tolerance to minus 7 degrees Celsius has been obtained in self-pollinating buckwheat. The plants are exposed to freezing temperatures that decrease 2 degrees per hour until the set temperature of minus 7 degrees. It remains at this temperature for one-half hour and then the temperature increases to 5 degrees Celsius over a ½ hour period. Therefore the plants are below freezing for more than 4 and ¼ hours. The tolerance is both in the seedling stage and at maturity, however, it decreases slightly at maturity. The development of frost tolerant lines will allow seeding to take place at a much earlier date, thus allowing for increased yield from later maturing lines.