Heading Synchrony and Yield Components of Barley Grown in Subarctic Environments
- Stephen M. Dofing and
- Charles W. Knight
Synchronous heading is an important characteristic of barley (Hordeum vulgare L.) grown in subarctic conditions, in which short growing seasons, cool temperatures, and the potential of early snowfall necessitate timely harvest. Kernels on late-developing spikes often fail to mature under these conditions, resulting in harvest delay and reduced grain quality. This study was conducted to determine the influence of seeding rate on heading synchrony and yield components of barley grown in subarctic environments. Three spring barley cultivars were evaluated at seeding rates of 22, 65, 108 kg ha−1 at Palmer and Fairbanks, AK, in 1990 and 1991. Heading synchrony was assessed by determining the range and standard deviation for the interval from sowing to spike appearance. for all cultivars at both locations, growing degree days (GDD) to spike appearance had a narrower range and a reduced standard deviation with higher seeding rates. Averaged across cultivars and environments, seeding rates of 22, 65, and 108 kg ha−1 resulted in standard deviations of GDD to spike appearance of 80, 68, and 64, respectively. Earliest maturity was obtained with the 108 kg ha−1 seeding rate, and grain yield was nearly identical to the 65 kg ha−1 rate. Increasing seeding rate from 65 to 108 kg ha−1 caused a greater compensatory decrease in kernels per spike than kernel weight. In similar environments, use of relatively high rates of seeding is recommended to reduce time to maturity, minimize number of late developing tillers, and optimize grain yield.
Copyright © . .