This article appeared in the Spring 2014 issue of Pulse Crop News.

Competitive ability for field peas using genotypic mixtures sets stage for additional research.

Genotypic mixtures of pulse crops may provide opportunities for growers as the strength in the mixture may be able to reduce disease, increase yields or even suppress weeds. A successful mixture is one where components show compatibility and interact positively with each other. While the use of this theory in agriculture is not common, one scientist is looking into how it might work for improvements to field pea production.

Understanding current production challenges such as the emergence of herbicide resistant weeds and poor competitive ability of pulses when facing weed pressure, Dr. Chris Willenborg, University of Saskatchewan researcher (formerly with the University of Alberta), was successful in accessing Alberta Pulse Grower Commission funding and Canadian Agricultural Adaptation Program funding through Agriculture and Food Council of Alberta to support work on improving field pea production and competitive ability using genotypic mixtures.

Mixtures for the study were chosen based on genetic relatedness. Genetic relatedness can express itself in people by eye and hair colour and other attributes but it really means that you’ve come from the same gene pool and you have shared ancestry like a mother and daughter or father and son. For the study, four semi-leafless field pea cultivars were chosen based upon relatedness – two sister lines, one common parent and one distantly related genotype.

Dr. Willenborg looked at how mixtures improve growth, production and competitiveness of field pea in the presence and absence of weeds and also explored if genetic relatedness is a consideration on the choice of genotypic mixtures with and without weed pressure. Weed pressure for the study was introduced using barley as the ‘pseudo weed’ in the plot research. Barley was chosen because is a common volunteer in field pea crops in Alberta. Plots were chosen in two Alberta research locations at Lethbridge and St. Albert.

Over the time of the study, the research team saw differences between monocultures and mixtures. If growers are using poor competitive pea genotypes weeds can take over and the results are that pea yields are reduced. Dr. Willenborg observed that competitive ability improved by combining the poor competitor types with more vigorous ones. In addition, he hypothesizes that adding more related lines to the mixture may make for better competition against weeds.

How does this translate for farmers? It is a challenge because producers are continually looking for varieties with greater vigor and competitive ability. In addition, if markets move to demanding more definitive attributes for field pea, for example in value added ingredient uses, it may become a requirement for monocultures for consistency of product. This certainly says more work is needed in this area to counterbalance production solutions for weed competition issues with potential market demands.

Dr. Willenborg and his colleagues believe there is potential for improved competitiveness but further research is needed. To that end, Dr. Willenborg was successful in securing a second round of funding to support his continued work on this project. More results will be shared with growers as the project continues.