Cultivation for early winter seeding of spring wheat [triticum aestivum] in central Hokkaido [Japan]: Relations between seeding date and winter survival
1998
Sato, M. (Hokkaido. Central Agricultural Experiment Station, Naganuma (Japan)) | Sawaguchi, A.
Cultivation for early winter seeding of spring wheat is tested to extend growing periods and to make the wheat mature earlier in central Hokkaido, where soils \are covered by snow but don't freeze in winter. In varietal trials using winter and spring wheat varieties at Naganuma, when the plants emerged and grew 1-2 leaves before continuous snow covering, two winter wheat varieties could survive 61.0-100% if seeding plants until spring, and three spring wheat varieties showed a large annual variation (0.4-54.9%) for their winter survivals. On the other hand, when the emergence did not occur before continuous snow covering, all five varieties survived at a relatively high rate. In seeding date trials using spring wheat cv. "Haruyutaka" at 3 locations (Naganuma, Shibetsu, and Pippu), the mean values for accumulated soil temperature and accumulated air temperature from seeding to emergence in early winter seeding was 140 degrees C and 115 degrees C, respectively. On a basis of the past climate trend at some points in central Hokkaido, we considered that an earliest limit of a seeding date for early winter seeding of sprig wheat if plants were to survive safely in winter was about 20-25 days before the average date of continuous snow covering
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