The Bean Report – August 2, 2023

Aug 02, 2023

Soybeans range from R4 (full pod) R5 (beginning seed).

Moisture limitations are apparent in some fields. Soybeans flip their leaves over to reflect sunlight, reducing moisture demands for the crop. Soybeans that were exposed to drought stress during vegetative growth stages are better equipped to handle drought stress now during reproductive stages. Water limitations in pulse and soybean crops →
Hail continues to hit select areas of the province. If your soybeans have been hit by hail, estimate yield loss using the latest research reports from the soybean and pulse agronomy lab. The R5 growth stage is the most susceptible and maturity may be delayed. Yield loss estimates due to defoliation and node breakage from hail →
Soybean aphids populations have remained low. A few fields in eastern Manitoba are approaching economic thresholds (250 aphids/plant and increasing). Once soybeans have reached R6 (full seed), they are considered safe from aphids. Managing soybean aphids →
Disease pressure has been low across the province. Phytophthora root rot and northern stem canker are showing up more often in fields with tighter soybean rotations.

Video: Do Cold Temps Impact Emerging Corn & Soybeans? | Pioneer Agronomy

A cold snap swept across west central Minnesota and eastern South Dakota, bringing frost, fog, and temperatures dipping into the 20s—raising urgent questions about early crop damage.

Pioneer Agronomist Eric Rice breaks down what those overnight temperatures could mean for emerged corn and soybeans, how to assess frost injury, and why patience is key before making any replant decisions. Learn the critical differences between corn and soybean growing points, what cosmetic vs. serious damage looks like, and how last week’s high winds may also be influencing what you’re seeing in the field.

Watch for:

• Frost thresholds for early-season crop damage

• Why corn may be more resilient than it looks

• Soybean growth stages and frost susceptibility

• How to evaluate brittle stems and discolored tissue

• Why waiting 4–5 days before assessing stand loss matters

• When to contact your local Pioneer agronomist or sales representative