Winter’s cold grip across the country isn’t deterring the soil pathogens that lie in wait for spring warmth and seeding to start their destruction on field crop yields and plant health. Pythium, phytophthora and aphanomyces are three root rots that are prevalent in soils across the prairies and in Ontario that plague soybean, cereal and pulse crops.

The problem with these pests

Pythium root rot has multiple hosts and can be found across the country. It’s particularly hardy and can survive in the soil over a wide temperature range, just waiting for the ideal weather and soil conditions to attack crops including soybean seeds as soon as 90 minutes after planting. As growers increasingly rely on metalaxyl for control of pythium, some species are evolving increased tolerance to metalaxyl.

Phytophthora root rot is a pervasive rot that’s hosted by soybeans, endemic to prairie soils and very common in Ontario. Four different races have been identified in Manitoba alone. And phytophthora is the number one disease that’s impacting soybean yields around the world.

Aphanomyces is a devastating root rot that just seems to be everywhere. If you’ve grown pulses in Western Canada in the last five years, your soil is probably harboring this pathogen. And unfortunately, there is general agreement among researchers in Western Canada that aphanomyces spores are naturalized across the prairies.

The best approach to control

“Your best defense against these deadly pathogens includes integrated and preventative strategies,” says Graham Collier, Technical Manager for Western Canada with Nufarm. “There are three key tips for controlling these pathogens – crop rotation, using resistant varieties if available and seed treatment.”

  1. Crop rotation should consider the window between host crops for a specific pathogen and how long the majority spores are able to survive between crops.
  2. Look to seed genetics to provide resistant varieties for phytophthora.
  3. Seed treatments help reduce the disease severity, reduce the production of inoculum from the pathogens, and prolong the viability of genetic resistance of a seed variety to these pathogens.

INTEGO® Solo is a Group 22 fungicide registered for control of pythium in a broad range of field crops, and phytophthora in soybeans. It also suppresses aphanomyces in field peas and lentils. INTEGO Solo contains a new active ingredient (ethaboxam), and when used together with metalaxyl delivers multiple modes of action for a great resistance management tool, especially for pythium species that are showing resistance to metalaxyl alone.

NipsIt® SUITE contains three active ingredients – Group 4 insecticide, Group 3 fungicide and Group 4 fungicide for broad-spectrum protection against most early season insect and disease pests in cereals.

Want to know more? Ask a Nufarmer at 1.800.686.5444, visit and follow us  @NufarmCA.