Thesis
Off season sowing and comparative overwintering traits of Spring, Winter, and facultative habit wheat cultivars
Washington State University
Master of Science (MS), Washington State University
2012
Handle:
https://hdl.handle.net/2376/103064
Abstract
Soft white (SW) wheat represents 75% of Pacific Northwest production. Hard red classed wheat maintains market premium over SW creating interest in producing hard red wheat. Off season sowing may increase productivity and flexibility for hard red production. Three hard red winter (HRW), four hard red spring (HRS) and two facultative soft white (SWF) habit cultivars were evaluated for overwintering traits and viability of off-season sowing. Field trials were conducted in 2010 and 2011 at four locations with three off-season sowing dates. Controlled environment studies characterized overwintering traits. Vernalization assessment measured final leaf number (FLN) at maturity after six vernalization time treatments. Photoperiod was assessed by FLN after short-day and long-day diurnal period exposure. Freezing tolerance was assessed at -4, -6, -8, -10, -12, -14, -16, and -18⁰C by scoring plant survival. Freezing mortality occurred for spring cultivars in all 2010 field trials but only at the coldest locations in 2011. Plants sowed mid-winter and early spring 2011 averaged 30% reduced emergence after seed was misplacement in cool, water logged soils. Yields of HRW and SWF averaged 4500 kg ha-1 and HRS averaged 3000 kg ha-1 in late fall sowing, while mid- winter and early spring sowing averaged near 2700 kgha-1 across cultivars. Early spring sown HRS yielded higher than average area yields. Early spring sown HRW were green at harvest due to inadequate vernalization. HRS produced 2% higher protein than HRW. HRW had high, SWF had moderate, and HRS had no vernalization requirements and sensitive cultivars had variable vernalization time to saturation. HRW and Goetze were sensitive and HRS and Alpowa were insensitive to photoperiod. HRW showed LD50 from freezing between -11° and - 13°C, SWF between -10 and -8°C, and HRS between -5.5 and -5°C. Vernalization sensitivity correlated to freeze tolerance values (r >0.75) and field winter survival (r >0.70). Photoperiod sensitivity correlated with increased yield (r>0.6) in cool climates and earlier sowing, but not field survival (r> 0.2). Earlier sowing of HRS can improve yield. Mid winter and early spring sowing had no cold mortality. Early maturing HRW and SWF can be sown later and mature for harvest.
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Details
- Title
- Off season sowing and comparative overwintering traits of Spring, Winter, and facultative habit wheat cultivars
- Creators
- Ross Kennington Wagstaff
- Contributors
- Stephen O. Guy (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Crop and Soil Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525135301842
- Language
- English
- Resource Type
- Thesis