A new program to manage weeds in Ontario’s edible beans

Edible bean plants are very sensitive when they are exposed to weeds, resulting in an average yield loss of 58 per cent, according to research conducted in Ontario.

That means growers should be diligent in managing weeds in their fields, but edible beans are also quite sensitive to many herbicides – so much so that many soybean herbicides can’t be used without causing injury to the edible bean crop.

In fact, there was only one soil-applied herbicide for broadleaf weed control registered for use in Ontario, for edible beans, when an Ontario Bean Growers research project on weed control was initiated. So, growers had been searching for additional tools for better weed management. A new herbicide showed promise, but, there had been little available information on its crop safety, efficacy, environmental impact, and economic sustainability in Ontario’s climate and soil.

With support from Growing Forward 2, renowned bean researcher Dr. Peter Sikkema, of the University of Guelph Ridgetown Campus, led a four-year Ontario Bean Growers project to complete research trials to learn more about how this herbicide performs on various types of edible beans in Ontario. Through this research, the most efficacious, environmentally sustainable and economically profitable weed management programs in edible beans were identified.

Specifically, white bean yields were higher when the herbicide was worked into the soil before the crop was planted (pre-plant incorporated) or applied before the plants emerged from the soil (pre-emergence).  Weed control was reduced when the herbicide was applied after the weeds had emerged from the soil (post-emergence). When applied post-emergence, researchers found that the tolerance was market class specific with greater injury in adzuki bean.

The weed control performance and yield impact while using the herbicide was also evaluated when used in tank mixes either pre-plant incorporated (PPI) or pre-emergence (PRE). Overall, both showed good weed control and yields comparable to the weed-free control in white beans.

Controlling weeds more effectively with less impact on the crop results in higher crop yields - ultimately, this can translate into greater returns for Ontario bean growers.

Funding for this project was provided by Growing Forward 2 (GF2) a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists with the delivery of GF2 programming in Ontario.