Blackshaw, R. E., Johnson, E. N., Gan, Y., May, W. E., McAndrew, D. W., Barthet, V., McDonald, T. and Wispinski, D. 2011. Alternative oilseed crops for biodiesel feedstock on the Canadian prairies. Can. J. Plant Sci. 91: 889–896. Increased demand for biodiesel feedstock has encouraged greater napus canola (Brassica napus L.) production, but there may be a need for greater production of other oilseed crops for this purpose. A multi-site field study was conducted to determine the oil yield potential of various crops relative to that of napus canola in the semi-arid, short-season environment of the Canadian prairies. Oilseed crops evaluated included rapa canola (Brassica rapa L.), juncea canola (Brassica juncea L.), Ethiopian mustard (Brassica carinata L.), oriental mustard (Brassica juncea L.), yellow mustard (Sinapis alba L.), camelina (Camelina sativa L.), flax (Linum usitatissimum L.), and soybean [Glycine max (L.) Max.]. Crop emergence and growth were generally good for all crops, but soybean did not fully mature at some locations. The number of site-years (out of a total of 9) that crops attained similar or greater yields compared to napus canola were camelina (6), oriental mustard (5), juncea canola (3), flax (3), soybean (3), rapa canola (2), yellow mustard (2), and Ethiopian mustard (1). The ranking of seed oil concentration was napus canola=rapa canola= juncea canola=flax>camelina=oriental mustard>Ethiopian mustard>yellow mustard>soybean. Considering yield and oil concentration, the alternative oilseed crops exhibiting the most potential for biodiesel feedstock were camelina, flax, rapa canola and oriental mustard. Oils of all crops were easily converted to biodiesel and quality analyses indicated that all crops would be suitable for biodiesel feedstock with the addition of antioxidants that are routinely utilized in biodiesel fuels.

Field crops influence the biotic properties of the soil, impacting the health and productivity of subsequent crops. Polymerase chain reaction and 454 GS FLX pyrosequencing of amplicons were used to clarify the legacy of chickpea and pea crops on the quality of the bacterial community colonizing the root endosphere of subsequent crops of wheat, in a replicated field study. Similar communities of root endosphere bacteria were formed in durum wheat grown after pea and chickpea crops when chickpea crops were terminated as early as pea (July). Termination of the chickpea crops in September led to the domination of Firmicutes in wheat root endosphere; Actinobacteria dominated the wheat root endosphere following early pulse crop termination. The architecture of wheat plants was correlated with the composition of its root endosphere community. High grain yield was associated with the production of fewer but larger wheat heads, the abundance of endospheric Actinobacteria and Acidobacteria, and the scarcity of endospheric Firmicutes. Pulse termination time affected wheat root endosphere colonization strongly in 2009 but weakly in 2010, an abnormally wet year. This study improved our understanding of the so-called "crop rotation effect" in pulse-wheat systems and showed how this system can be manipulated through agronomic decisions.

Pageni, B. B., Lupwayi, N. Z., Akter, Z., Larney, F. J., Kawchuk, L. M. and Gan, Y. 2014. Plant growth-promoting and phytopathogen-antagonistic properties of bacterial endophytes from potato (Solanum tuberosum L.) cropping systems. Can. J. Plant Sci. 94: 835–844. Endophytes are microorganisms that live within a plant without harming it. Bacterial endophytes were isolated from roots of potatoes (Solanum tuberosum L.) grown under different rotations (3 to 6 yr in length) and soil management (CONV, conventional; CONS, conservation) in irrigated cropping systems with dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.) spring wheat (Triticum aestivum L.) and timothy (Phleum pratense L.). The endophytes were characterized for nitrogen fixation potential, phytohormone production and phytopathogen-antagonistic properties. The nitrogen-fixing nitrogenase (nifH) gene was detected in potato grown in all rotations, presumably partly because the soil in all rotations contained Rhizobium leguminosarum bv. phaseoli from the dry bean phase. Sequence analysis revealed that it was homologous to the genes found in Burkholderia, Azospirillum, Ideonella, Pseudacidovorax and Bradyrhizobium species. Indole acetic acid (IAA) hormone production by endophytes isolated from potato grown under CONS management was 66% greater than that those isolated from potato grown under CONV management, and tended to be greater in longer than shorter rotations. When 12 endophytes were inoculated to dry bean, four increased shoot biomass by 27–34%, and six increased total (shoot+root) biomass by 25% on average. Endophytes from the longer CONS rotations (4–6 yr) resulted in significantly higher (by 9%) shoot biomass than the shortest CONS (3 yr) rotation. Six of 108 endophyte isolates exhibited antagonistic properties (reduced pathogen biomass by 12 to 58% in dual culture assays in liquid media) against potato pathogens Pectobacterium atrosepticum, Fusarium sambucinum and Clavibacter michiganensis subsp. epedonicus. All the six isolates were from CONS soil management. Therefore, the benefits of long rotations, with their associated CONS soil management, to crop productivity in these irrigated cropping systems probably include nutritional (biological nitrogen fixation and IAA hormone production) and disease-control benefits imparted by endophytic bacteria.

Liu, C., Gan, Y. and Poppy, L. 2014. Evaluation of on-farm crop management decisions on canola productivity. Can. J. Plant Sci. 94: 131–139. This study determined key factors affecting canola productivity in western Canada and evaluated the differences among soil-climatic zones in canola crops responding to the key agronomic factors. A total of 68 canola farm fields were randomly selected in western Canada, and multiple correspondence analysis, coupled with multivariate predictive model with partial least squares projection and regressions, was used to analyze the data set. Canola produced in Alberta averaged 2500 kg ha−1, and was 23% greater than canola produced in southern Saskatchewan, 10% greater than canola produced in northern Saskatchewan, and 59% greater than canola produced in Manitoba. Canola produced on chem-fallow averaged 2557 kg ha−1, and was 17% greater than canola grown on cereal stubble, or 43% greater than canola grown on pea/lentil, corn stubble. Canola grown on canola stubble produced 54% of the seed yield as canola grown on cereal stubble, or 46% of the seed yield as canola grown on chem-fallow. Shallow and earlier seeding with narrow row spacing increased canola seed yields consistently. Canola receiving K fertilizer increased seed yield by an average of 25% compared with those receiving no K fertilizer. Straight combine resulted in 500 kg ha−1 or 24% more seed yield than conventional swath-combine method. Those key factors may serve as the first-hand information in the development of sound guidelines for less experienced canola producers in western Canada.