The profitability of diverse crop rotations and other cultural methods that reduce wild oat (Avena fatua)

Citation

Smith, E.G., Neil Harker, K., O’Donovan, J.T., Kelly Turkington, T., Blackshaw, R.E., Lupwayi, N.Z., Johnson, E.N., Pageau, D., Shirtliffe, S.J., Gulden, R.H., Hall, L.M., Willenborg, C.J. (2018). The profitability of diverse crop rotations and other cultural methods that reduce wild oat (Avena fatua). Canadian Journal of Plant Science, [online] 98(5), 1094-1101. http://dx.doi.org/10.1139/cjps-2018-0019

Plain language summary

Canadian farmers are seeing increasing issues with herbicide resistant weeds including wild oat, which is one of the more important weed species that impact farmers. As a consequence there is a need to evaluate the potential of alternative cropping systems based on integrated weed management principles. A 5-yr field study at eight sites across Canada was used to evaluate the profitability of alternative cropping systems that have the potential to control wild oat using cultural practices in conjunction with herbicides. Cultural practices included twice the recommended seeding rates, fall-seeded winter crops, barley silage, fallow, and alfalfa. The profitability of different cropping systems varied by experiment location. For many locations, combinations of barley silage and fall-seeded winter crops without wild oat herbicide application were as profitable as a system of growing canola and wheat where wild oat herbicide was applied every year. Unprofitable systems generally included those with fallow, alfalfa, and fall-seeded winter crops in regions with rates of high winter kill during overwintering of winter crop types. The research demonstrated that wild oat control can be achieved with diverse cropping systems that are as profitable as conventional annual cropping that relies on herbicide control of wild oat. This research helps to improve farmer's bottom line as well as limits the need for herbicide application to only those situations where it is needed.

Abstract

With the increasing resistance of wild oat (Avena fatua L.) to herbicides, there is a need to evaluate the potential of alternative cropping systems based on integrated weed management principles. A 5-yr field study at eight sites across Canada was used to evaluate the profitability of alternative cropping systems that have the potential to control wild oat using cultural practices in conjunction with herbicides. Cultural practices included twice the recommended seeding rates, fall-seeded winter crops, barley (Hordeum vulgare L.) silage, fallow, and alfalfa (Medicago sativa L.). Seven of the 14 cropping systems in this study did not include wild oat herbicide for three consecutive years, controlling wild oat entirely by cultural practices. Cropping system profitability varied by location. For many locations, combinations of barley silage and fall-seeded winter crops without wild oat herbicide application were as profitable as a system of canola (Brassica napus L.) and wheat (Triticum aestivum L.) with wild oat herbicide applied every year. Unprofitable systems generally included those with fallow, alfalfa, and fall-seeded winter crops in regions with rates of high winter kill. Wild oat control can be achieved with diverse cropping systems that are as profitable as conventional annual cropping that relies on herbicide control of wild oat.