Pulse & Soybean Crop Update

Soybeans range from R3 (beginning pod) to R4 (full pod).

• Soybean plant height and biomass have increased dramatically over the last two weeks as the plants continued flowering and pod development.
• Varying degrees of stem, leaf, flower and pod deformations have been noted and have been attributed to a variety of causes including:

Rapid Growth Syndrome – Shows up as bubbling and crinkling and curling of new leaves since the leaf interior is growing quicker than the leaf veins and edges can keep up with. See Figure 1 below.

Suspected Herbicide Drift – Concerns regarding suspected Group 4 drift in particular have been reported this year. Caution should be taken with such diagnosis based on visual assessments only as rapid growth syndrome can produce some comparable symptoms. See Figures 2 and 3 below.

Suspected Environmentally Induced Male Plant Sterility – Symptoms with this disorder can be very odd and hard to verify. Extreme fluctuations in temperature which includes very hot conditions can occasion induce plants to become sterile. Reproductive structures like growing points, flower and pods are particularly vulnerable. Often these plant parts become shrunken, hard and demonstrate odd textures. No seed is usually produced from affected plants. See Figure 4 below.

• Plant response to deficient soil moisture levels have been observed including soybeans flipping their leaves over or clamping their leaves shut to reflect sunlight and conserve moisture.
• Soybean aphids are becoming more prevalent in a greater number of fields – more on this in this week’s Bean Report.
• The first reports of two-spotted spider mites have been received – more on this in this week’s Bean Report.

Field peas range from R4 (full pod) to R6 (mid maturity), with earlier seeded fields at R7 (full maturity) and have received or are soon to receive pre-harvest herbicide applications.

• Pea aphids are being found within pea fields, but grower concerns have subsided since fields have developed beyond the crops stages where economic damage to yield would occur.
• Fungicide applications have come to end now that the crop has reached the full pod growth stages where seeds have filled the pod cavity. Disease is not expected to lower yield any further. As well, many fungicide products have 30-day pre-harvest intervals and field pea harvest is expected to commence this week in some areas if weather allows.
• Have questions about field pea desiccation? See this week’s Bean Report