Production Updates

Alternaria and green seeds

Experiments at the Agriculture Canada research station in Saskatoon have shown alternaria blackspot can increase green seed counts in Polish canola.

When pods of Polish canola collected in 1990 from Medstead, Sask. were split open, green seeds were often found next to deep blackspot lesions.

Those green seeds contained much higher levels of alternaria than normal seeds.

The average incidence of alternaria was 39 percent in green seeds and just four percent in the normal seeds.

In a growth chamber experiment, plants inoculated with alternaria at the end of flowering produced nine percent green seed. Uninoculated plants produced no green seeds.

Read Also

VIDEO: Green Lightning and Nytro Ag win sustainability innovation award

Nytro Ag Corp and Green Lightning recieved an innovation award at Ag in Motion 2025 for the Green Lightning Nitrogen Machine, which converts atmospheric nitrogen into a plant-usable form.

Current research is aimed at controlling the disease with chemical seed treatments, fungicides and harvesting methods.

Blackspot is caused by different species of alternaria fungi.

The disease causes reduced yield, oil content and seed germination, as well as increased dockage, in both Argentine and Polish canola.

– Agriculture Canada

Be wary of wild tomatoes

Wild tomato, a native plant that grows in small numbers throughout Saskatchewan, is becoming an increasing problem in lentil crops.

“As lentil production grows, and as new low-growing and open-canopied crops such as beans and chickpeas are added to rotations, the potential for problems with this annual weed increases dramatically,” said Rick Holm, a professor of plant science at the University of Saskatchewan.

Holm said wild tomato can cause a loss of yield in lentil and wheat crops.

In one of four field trials with wheat, there was a 12 percent yield reduction in plots with wild tomato.

In lentil field trials, yield loss was evident in three of six trials and, in one trial, the loss was 62 percent.

Wild tomato can also cause headaches when harvesting low-growing crops, Holm said.

Juice and seeds from the fruit of the weed mixes with dust and debris during harvest. The mixture can build up on the combine concaves, augers and grain elevators.

Wild tomato juice can stain lentil seed, and debris can be stuck to seed that was moistened with the wild tomato’s juice.

Ways to control wild tomato include:

Work and harvest patches of wild tomato separately from the rest of the field.
Sow patches with competitive cereal crops the next year and use certified seed to reduce the risk of introducing wild tomato seed, or of moving it from field to field.
Clean all harvesting equipment before leaving a field with a large wild tomato population.
Don’t seed lentils in locations where there are patches of wild tomatoes.
Colorado potato beetles feed on wild tomatoes and should be encouraged to move into fields with large populations of the plant.