Prairie Giants Crop Report

The Prairie Giants Crop Report

Field observations at your fingertips

June 29, 2020

Taylor Kurtenbach

Welcome to the Prairie Giants Crop Report! We’ll be breaking down our observations from the field into a concise, semi-regular report.

Green Grass Bug Damage
A grower submitted the following photo of mysterious damage on his wheat crop… After consulting John Gavloski, an entomologist with Manitoba Agriculture, we concluded it was potential feeding from green grass bug. They overwinter as eggs, with adults emerging in the spring to lay eggs in cereals and other grasses. Both adults and nymphs (immature form) feed on the leaf and stem tissue. Fortunately for us, they are not considered a serious pest and cereal crops tend to outgrow this damage!

Fungicide in Field Peas
The time for fungicide application in peas is quickly approaching! Common diseases with an economic impact include mycosphaerella blight, powdery mildew, and white mold. A timely fungicide application, start of flowering or first sign of disease, can help protect your yield potential.

Pea Aphids
Another pest to be on the lookout for is pea aphids. They overwinter as eggs on perennial legumes, hatching into females which produce further generations asexually. After 2 to 3 generations the females become winged, migrate to annual hosts, and produce more generations.

Feeding during flowering to early pod stage can result in reduced yields and small seed size, so scouting during this time is important. This can be done using a sweep net (five 180° sweeps) or tapping the top 8” of the vine into the palm of your hand. An insecticide application is warranted if you find 9 to 12 aphids per sweep, or 2 to 3 per plant tip. Pressure throughout the field can be variable, so it is important to take a large enough sample size.

Pea aphids do not tend to coincide with fungicide timing, as they do the most damage late flower to early pod.

Check out this page from Manitoba Agriculture for more information:

https://www.gov.mb.ca/agriculture/crops/insects/aphids-on-peas.html