1993 Volume 62 Issue 3 Pages 372-377
Degrees of frost damage were observed for three varieties of winter wheat at the different seeding densities. Shoot nitrogen, phosphorus, potassium, sugars and starch contents were measured at the internode elongation stage. Grain yield was high in the low seeding density plots (150 seeds/m2) and low in the high seeding density plots (300 seeds/m2). Although the early tillers died from frost damage, the late tillers escaped frost damage in the low seeding density plots. These tillers showed high nitrogen and potassium contents of shoots, so that they bore spikes and contributed much to yield. In the high seeding density plots, shoot nitrogen and potassium contents were small and the later tillers were weakened. Consequently, these tillers did not bear spikes, even after early tillers died from frost damage, so that grain yield showed a marked decrease in the high seeding density plots.
