AV俱乐部

Organic Agriculture Centre of Canada

Organic producers have been asking, for years, for organic varieties that meet their unique growing conditions. Are they any closer to getting what they want?

Organic producers currently use varieties bred for conventional systems. Many feel that these varieties, selected from research plots that receive synthetic fertilizers and are kept nearly weed free, may not be suited to organic production.

In the past, most breeders suggested that the improvements in disease resistance, shortened time to maturity, and greater yield more than make up for any difference in response to input levels.

A few cereal breeders on the prairies have taken the organic challenge seriously. It takes several years to bring a new variety to market. This makes breeders cautious about new directions. For the breeders, the first step in breeding for organic production in Canada was a 鈥減roof of concept鈥�, research establishing that it made sense to do so.

At University of Alberta, Todd Reid and Dean Spaner crossed two very different wheat varieties to produce 79 different breeding lines. They grew these out under both organic and conventional management, comparing their performance. The lines they selected as the best 10% under organic management were different from those selected as the best 10% under conventional management. This suggests that conventional varieties may not be the best option for organic producers and organic producers would benefit from selection under organic management.

A second 鈥減roof of concept鈥� experiment was conducted at the University of Manitoba, by Anne Kirk, Stephen Fox and Martin Entz. They grew populations of wheat for four generations under both organic and conventional management. They then grew the best lines selected from each population and environment under both management systems.

They found that all populations performed similarly under conventional management, whether they were selected under organic or conventional management. The populations selected under organic management grew better in the organic system than the populations selected under conventional management. These organic selections had larger kernels and higher protein levels whether grown organically or conventionally. This suggests that an organic breeding program would be of value.

Having proven the concept, researchers are working to develop wheat and oat varieties for organic production. Researchers at the Universities of Saskatchewan, Alberta and Manitoba, have grown historical and modern cereal varieties under organic management on research farms and on organic farms. They identified characteristics of varieties that did well under organic management. In general, varieties with early vigour (those that emerged and covered the ground quickly) were better competitors with weeds. Tall, leafy varieties often did well.聽

Selection criteria in the organic breeding programs include agronomic characters such as height, straw strength, yield, early maturity, and disease resistance; and quality characteristics such as test weight, milling, gluten strength and baking quality.

In 2010, the University of Manitoba and Agriculture and Agri-Food Canada Winnipeg researchers introduced a new model of plant breeding to the prairies: participatory wheat breeding. Participatory means that farmers participate as an integral part of the plant breeding process. This ensures that the research is relevant to farmers鈥� needs by broadening the number of environments where selection is done.

Researchers are asking participants to seed a small area to one or more populations of wheat (about 30 m²). Farmers are asked to go through each plot and remove the plants that they don鈥檛 like 鈥� small, weak, lodged, diseased or otherwise unsuitable. Each year, farmers save the seed and plant it out in the following year. After several generations, this 鈥渘egative selection鈥� will result in populations adapted to their local conditions and management. Researchers hope that the populations will have more genetic diversity, and be more able to respond well to stress and variable environments, as well as more specifically suit the farmers鈥� preferences.

So are Canadian prairie organic farmers getting closer to having cereal varieties bred for their unique management system? It is a slow process, with research started in 2004 only now resulting in lines being proposed for registration. According to Stephen Fox, wheat breeder at Agriculture and Agri-Food Canada, Winnipeg, candidates are being entered into registration tests.聽 According to Jennifer Mitchell-Fetch, oat breeder at the same facility, oat varieties may be ready for registration as early as 2013.

This article was written by Brenda Frick on behalf of the OACC with funding provided by Canada鈥檚 Organic Science Cluster (a part of the Canadian Agri-Science Clusters Initiative of Agriculture and Agri-Food Canada's Growing Forward Policy Framework).聽 The Organic Science Cluster is a collaborative effort led jointly by the OACC, the and industry partners. For more information: oacc@dal.ca or 902-893-7256.


Posted June 2011