After two crop years of research with the Biofuels Cropping Systems Research project, valuable data is being utilized to inform growers, industry and other researchers about the potential of oilseed crop production in Washington. Future research plans have been adjusted with revised research objectives and experiments to accommodate our shifting understanding and knowledge of biofuel cropping. While great progress has been made in defining benefits and constraints of biofuel cropping in WA state, there are many questions and issues that remain unresolved. A summary of 2010-2011 future plans can be found in the final section (p. 101). Highlights of project progress to date include:
1. Cold tolerance tests in the lab and late-seeded field trials of commercial winter canola varieties show little to no tolerance to early frosts when the plants are seedlings. However, earlier planting dates in June and July with and without interseeded legumes have resulted in consistent stand establishment. A 34-entry canola variety field trial will identify cold hardy lines, as during Fall 2009 we had the most extreme cold stress without snow cover at Pullman in 50 years, and only the third time in 55 years at Davenport. Regrowth and yield measurements in 2010 will determine the success of utilizing winter canola as a biennial crop, both as a forage and seed source, in eastern and central Washington. Visual surveys at Davenport indicate that some winter varieties at Davenport survived the severe freezing stress.
2. Canola has proven to be a very effective scavenger of residual soil N in both dryland and irrigated areas, based on our demonstrated maximum yield with no N fertilizer in irrigated canola, and our achievement of 80-90% maximum yield with no N fertilizer in dryland field studies. These results may lead to revision of currently published fertilizer N recommendations for canola in the PNW and ultimately alter life cycle analyses of energy inputs and GHG emissions for PNW canola production. Canola is being grown by deep well irrigators because it is an early maturing crop that saves water. Safflower was also produced with low N rates and deficit irrigation in central Washington.
3. Canola acreage is increasing in north central Washington as growers become more educated about the basic agronomics of production; several growers have modified equipment based on research results. A partnership established between the Colville Confederated Tribes, non-tribe growers, and several agencies has resulted in production of canola-based biodiesel that is used in a school bus on the reservation. There is potential to produce enough biodiesel to use in all of the school buses and logging trucks on the reservation, and canola meal for 10,000 head of cattle.
4. Winter canola production will ultimately be determined by market price in relationship to winter wheat. Winter canola was competitively priced with wheat over the past year, resulting in more positive economic analyses and encouraging more growers to experiment with canola.
5. Oilseed crop and variety recommendations can be more site-specific based on oil analysis and yield results from the different agroclimatic zones of Washington. The biodiesel industry has discussed making variety recommendations for narrowing quality specifications of feedstocks, and our oil composition analysis will help inform the industry on biodiesel quality related oil characteristics.
6. Early (mid-August) planted winter canola produced high yields at Puyallup, with two times the yield as a mid-September planting. Low yields of camelina, mustard and flax at Mt. Vernon may be fertility related; cool, wet weather also has an impact on crop success.
7. Data thus far show that winter canola uses more soil water than winter wheat and that grain yield of the crop after winter canola is lower than after winter wheat. However, several more years of multi-location field data are needed to validate this finding, since this is contrary to many grower testimonials that cite a yield boost following canola.
8. Camelina shows potential as an oilseed crop in the typical winter wheat-summer fallow region. The rotation it will most likely fit in is a 3-year winter wheat – camelina – summer fallow system. This cropping system, as well as several camelina agronomic studies, is being evaluated at Lind.
9. Plantback restrictions due to prior application of Group 2 herbicides in wheat-legume rotations are a major limitation to growers wanting to produce oilseed crops. Four camelina mutant populations have been identified with partial resistance to imi herbicides, and one with SU resistance, with no significant change in yield potential. Research this year will determine if a higher resistance level can be obtained.
10. Three commonly used seed treatments were not effective at controlling Rhizoctonia damping off; the most effective control strategies will be to avoid greenbridge problems, develop and use cultivars with good levels of genetic resistance, and crop rotation. Blackleg and Sclerotinia white mold have not yet been observed in dryland canola.
11. Successful establishment and winter survival of upland versus lowland switchgrass varieties, as well as other warm season grasses, varies depending on planting date and soil temperature. A flexible window of planting times will be critical to expanding acreage of grasses for future cellulosic ethanol production in the Columbia Basin.
12. Commercial herbicide labels for plantback restrictions in wheat-pulse crop rotations may need to be adjusted to longer intervals based on residual herbicide studies. In the long run, this might discourage growers from future use of these long term residual herbicides.
13. Field days, workshops, seminars, and collaborations with industry and other groups continues to be the focus of information transfer from the research projects. Attendance at 2009 events increased dramatically from 2008, indicating the interest level in oilseed crop production has not waned.