Off-Season Sowing of Spring, Winter, and Facultative Wheat Cultivars In the Pacific Northwest.

Offseason sowing of wheat in the Pacific Northwest can improve profitability, moisture utilization, and reduce hard red production risk. Three hard red winter (HRW), four hard red spring (HRS), and two facultative soft white (FSW) cultivars were planted at four locations and three sowing dates. Locations are characterized as cool high rainfall, cool low rainfall, warm medium rainfall, and warm irrigated climates. The three sowing dates were late fall (LFS), mid-winter (MWS), and early spring (ESS). Data was collected for winter mortality, disease rating, yield, test weight, and protein. Subsequent greenhouse studies characterized low temperature tolerance, vernalization and photoperiod requirements of these cultivars. HRS had total freezing mortality when LFS in the coldest location with <18% survival in other cool location and between 1 and 48% for warm locations, HRW and FSW had minimal mortality. There was no mortality for any cultivar when MWS or ESS. When LFS in all locations HRS yielded less than FSW and HRW, with HRW out yielding FSW in the three coolest locations. In warm locations when MWS yield was not different among classes. When MWS in cold locations HRW, FSW, and HRS yielded high to low in that order. In warm locations with ESS HRS out yielded other classes and HRW did not fully vernalize. There was no yield difference between classes when ESS at one cold location. Regardless of planting date, HRS produced 2-4% higher protein than HRW. A cool wet spring led to high rust incidence causing high variation in cultivar test weights, with a HRS and FSW 60-100 kg m-3 below average. Vernalization and freeze tests had strong correlation with field survival and production in LFS. Advantages of off season sowing are increased spring yield, weed competition, and reduced HRW cold mortality.