What to Do about Soybean White Mold in 2020
Jun 18, 2020
Soybean white mold (SWM) infects plants early, and can cause significant yield loss. Here are some considerations and tips to help you manage SWM in 2020.
Risk factors for white mold
Know your field history.
We saw heavy SWM pressure in 2019 that was widespread. If your fields suffered last year, it is likely that there is still inoculum in the soil this season. While planting this spring, you likely stirred up the SWM bodies, bringing them closer to the surface where they will germinate.
Watch conditions.
Since there is already SWM in the soil, the pressure of the issue will depend on the environmental conditions. Fortunately this spring's weather hasn’t been favorable for SWM growth. When highs are in the 70s, we generally see higher pressure than when temperatures are consistently in the high 80’s. We still encourage you to keep an eye on your high risk fields and continue with in-season management.
In-season soybean white mold management.
There are plenty of effective treatment options available if you find yourself with a SWM problem. Here are a few management options to consider.
Group 14 herbicides: Some group 14 herbicides elicit a response in plants that can protect against SWM. With a timely application, this route can be a more effective and economical option. It is recommended you apply a group 14 herbicide as soon as the first flower is spotted in soybean fields.
Foliar fungicides: There are multiple product options available, some may suppress the disease while others offer better control, chat with your Central Counties agronomist to decide which fungicide will work best for your situation.
We recommend adding a drift reduction adjuvant such as MasterLock®. This adjuvant helps optimize spray droplet size for better plant coverage-- the more active ingredient you can get into the canopy the better.
Be proactive.
Work with your Central Counties agronomist to develop a plan that fits your budget and management style. Being proactive is a better option than gambling on it not being an issue and ending up with yield loss.
Risk factors for white mold
- Cooler temperatures, below 85 degrees
- Typically found during the flowering period, R1-R3 growth stage
- Early planting resulting in early canopy closure which can reduce airflow and create an environment conducive to disease development
- Narrow row spacing
- Field topography
- Weed management
Know your field history.
We saw heavy SWM pressure in 2019 that was widespread. If your fields suffered last year, it is likely that there is still inoculum in the soil this season. While planting this spring, you likely stirred up the SWM bodies, bringing them closer to the surface where they will germinate.
Watch conditions.
Since there is already SWM in the soil, the pressure of the issue will depend on the environmental conditions. Fortunately this spring's weather hasn’t been favorable for SWM growth. When highs are in the 70s, we generally see higher pressure than when temperatures are consistently in the high 80’s. We still encourage you to keep an eye on your high risk fields and continue with in-season management.
In-season soybean white mold management.
There are plenty of effective treatment options available if you find yourself with a SWM problem. Here are a few management options to consider.
Group 14 herbicides: Some group 14 herbicides elicit a response in plants that can protect against SWM. With a timely application, this route can be a more effective and economical option. It is recommended you apply a group 14 herbicide as soon as the first flower is spotted in soybean fields.
Foliar fungicides: There are multiple product options available, some may suppress the disease while others offer better control, chat with your Central Counties agronomist to decide which fungicide will work best for your situation.
We recommend adding a drift reduction adjuvant such as MasterLock®. This adjuvant helps optimize spray droplet size for better plant coverage-- the more active ingredient you can get into the canopy the better.
Be proactive.
Work with your Central Counties agronomist to develop a plan that fits your budget and management style. Being proactive is a better option than gambling on it not being an issue and ending up with yield loss.