While travelling over the last couple of weeks, I have been hearing a lot of talk about how nice and tall everyone’s soybeans are this year.  Even in hard-hit areas with lots of moisture, most fields are rebounding.  In loam soils, soybean plants are getting very tall and some are starting to lodge. The fear is that White Mould will start to flare up in these areas.

First, let’s review the life cycle of White Mold (see below).

As you can see from the diagram, White Mould starts the previous season from an infected bean crop.  Sclerotia (often refer to as Rat Droppings) are produced on the plants, fall to the ground and are then dormant over the winter. They will germinate in the soil under wet, cool conditions and produce Apothecia “mushrooms” on the soil. These “mushrooms” release spores into the air and infect the neighbouring soybean plants. The “mushrooms” are visible to the eye, but they are often small and you need to look really hard to find them. Once spores germinate, they form Sclerotia on or inside the stem.  Some of the Sclerotia are usually blown out the back of a combine and are once again in the soil, waiting for an opportunity to germinate the following year, and therefore start the cycle over again.

White Mould can be very damaging to your crop. It can cause wilting, lodging and premature plant death, thereby reducing yields significantly. The abundant moisture and cool temperatures we have been experiencing lately are very favourable for White Mould growth. Take time to check your fields, especially the loam to sandy-loam fields you may have or those fields that you know have been a problem in the past.

There are products that may help control or suppress the disease.  AcapelaTM by DuPont states that they will suppress the disease with two applications. This may be an option you could use on your soybean crop. There is also a product called Contans® WG by UAP that is a biological fungicide that attacks and controls the Sclerotia in your soil.  This product needs to be applied to your crop residue after harvest. Contans® WG is recommended to be used for consecutive years to help reduce the disease in heavily infected fields.

Take the time to walk your soybean crop, scouting for this disease and take appropriate action if needed. If in doubt, call your local Maizex Representative. They would be more than happy to help.

Chuck Belanger, Maizex Seeds Yield Specialist, North Essex and South Chatham-Kent Counties
Twitter: @sprayman63