Wildrice (Zizania palustris) Varietal Differences in Response to Timing of Harvest.

Wildrice cultivars in Minnesota have been developed through recurrent selection within several heterogeneous populations. Different traits have been emphasized in different breeding populations, such as early maturity, high yield, and reduced seed shattering. How do these different populations compare for yield, shattering, etc. when harvested at different times? When is the best time to harvest such heterogeneous populations? In order to answer these questions, experiments were conducted on five populations at two locations: three high yielding and two early populations. These were harvested approximately 4-5 days apart. The design was split-plot with harvest timing as the main plot. Measurements included grain moisture, raw yield (adjusted for moisture), dry hulled yield, seed size, foliar disease ratings prior to harvest, lodging at harvest, and seed shattering. Yield adjustments using plant density as a covariate improved the statistical quality of the data. The changes in grain moisture related to the shape of the yield curve (both raw and hulled) provided insight into the optimum harvest time for each potential variety.