After a turbulent growing season, good weather finally has Ontario’s soybean crop maturing quickly and speeding toward harvest.
Soybeans are loving the September conditions, says BASF business representative Ken Currah, as they’re starting to ripen and mature. For many growers that means it’s time to consider pre-harvest burndown to either even up the crop moisture or handle weed escapes that could hamper harvest.
On this episode of RealAgriculture’s Soybean School, Currah looks at the ‘decision tree’ growers have to navigate to ensure an effective pre-harvest herbicide application. His first recommendation for both conventional and IP soybean growers is to check with their contract providers to determine whether they can use glyphosate in the tank mix. Agronomically, it’s a big help, but there may be restrictions depending on the end-use of the crop, he notes.
Currah adds that it’s important for growers to pay close attention to pre-harvest intervals. For instance, a herbicide like Eragon LQ requires three days in soybeans, but if glyphosate is added to the tank, seven days are required. (Story continues after the video.)
Proper timing is also important for an effective in-crop application. Currah says pod colour is the best way to assess timing. He wants to see 90 percent pod colour change. At that point, “the bottom pods are starting to look like they are ready to thresh out. Top pods may have a little tinge of green, but are generally yellowing off and starting senescence.” Typically, this stage corresponds with 80 percent leaf drop.
Currah says growers need to look at the weed spectrum across the field to determine their objectives. Should the pre-harvest pass focus primarily on weed control or is desiccation required to eliminate tall, woody weeds like lamb’s-quarters or Canada fleabane that could complicate combining. He also notes that it’s a good time to assess which spring weed control strategies worked and identify where adjustments are required.
Click here for more Soybean School episodes.