THE EFFECT OF DRYING TEMPERATURE ON CORN SEED QUALITY

Abstract

Seed produced on 3 widely grown public corn inbreds was tested for tolerance to drying injury. Inbred parents A632, B73 and Mo17 were grown in 1979 and 1980. The single cross H99 .times. H95 was used as a pollinator both years. Random ear samples were collected, to obtain ears with moisture percentages ranging from .apprx. 50-20%, and dried to 12% moisture at 35.degree., 40.degree., 45.degree. and 50.degree. C. Inbred parents differ in tolerance to high drying temperatures. A632 was the most tolerant to high drying temperatures whereas B73 and Mo17 were relatively intolerant. Field performance of dried seed was similar to that observed in laboratory tests. Combined analyses yielded significant inbred-parent by harvest-moisture by drying-temperature interactions for germination and cold-test emergence percentages. These interactions do not allow for simple recommendations of safe harvest moistures and drying temperatures. Components from the combined analysis that had a P > F of 0.30 or less were then used to predict mean values for A632, B73 and Mo17 germination, cold-test emergence, seedling dry weight and the ratio of shoot to root dry weight. Values for the ratio variable indicated that root development is more susceptible to injury than is shoot development. These predicted values provide seed producers with information on the quality responses that they could expect when seed of A632, B73 or Mo17 is harvested at different moisture contents and dried at different drying temperatures.