Effect of Harvest Method on Seed Yield of Coreopsis lanceolata L. and Gaillardia pulchella Foug.

Abstract

Seed of north Florida ecotypes of lanceleaf coreopsis ( Coreopsis lanceolata L.) and blanketflower ( Gaillardia pulchella Foug.) were sown in February 1998 and harvested manually or mechanically (portable seed stripper) at two different times during the growing season. Mechanical harvesting of both species was more efficient based on the length of harvesting time relative to the yield of clean seed but hand harvesting yielded substantially more clean seed. Date of harvest (mid-July or early October) had several significant effects on blanketflower yield and quality. The July harvest resulted in 67% higher clean seed yield, 45% higher clean seed yield rate (a measure of harvesting efficiency), 9% greater seed mass, and 95% greater germination rate than the October harvest. Date of harvesting for lanceleaf coreopsis (late June and late August) had minimal effects on clean seed yield or quality.