Development of Giant Foxtail under Several Temperatures and Photoperiods

Abstract

Giant foxtail (Setaria faberii Herrm.) was grown from seed in controlled climate rooms at temperatures of 50, 60, 70, and 80 F and photoperiods of 8, 12, 16, and 20 hours. An inherently poor primary root system resulted in slow and uniform growth during the first few weeks under all environmental conditions. Giant foxtail produced the most dry matter at the highest temperatures and longest photoperiods. No photoperiod inhibited flowering but photoperiod produced differences in development of inflorescences. Within any temperature, the longer the photoperiod the greater the size of panicle and number of seeds produced. Seed viability was high at 80 and 70 F, low at 60 F and zero at 50 F within all photoperiods.