By Darren Hefty
With wheat prices today, you need every bushel you can get. One of the best ways to put more bushels in your bins for a small investment is to use a pre-emerge herbicide. We’ve been talking about this since last fall in the newsletter and on Ag PhD because the results have been so impressive in the field.
Chances are, if you’ve been using a pre-emerge herbicide in your wheat, you’ve already found a favorite product to use. If you are new to using pre-emerge herbicides OR if you’ve been using them and are looking for other options, I’ll give you the low-down on which products are the best and how to get the most out of them.
Group 2 – Pre-Pare
In the Group 2 family, Pre-Pare is the key pre-emerge herbicide. It works well on foxtails, wild oats, and even has suppression of cheatgrass, Persian darnel, and Italian ryegrass. If you have broadleaf weeds that are not ALS-resistant you should see good results controlling a number of broadleaf weeds such as the mustards, field pennycress, and shepherds purse with suppression of henbit and wild buckwheat.
In soils with a pH above 7.0 and soil organic matter levels at 2.5 percent or below, some farmers are using a lower rate (0.2 oz/acre) and doing a great job on weed control for less money (under $4). On the other side, if your soil pH is below 7.0 and your soil organic matter is 3 percent or above, you should probably use the 0.3 oz/acre rate, which is still pretty inexpensive. Since you may have both of those conditions happening in the same field at times, talk to your local agronomist to determine the rate that is safe for the crop and effective at controlling weeds in your area. Pre-Pare can be lightly incorporated or left on the soil surface in no-till.
Group 15 – Zidua
Zidua is from a chemical family normally used in corn for grass control so it offers something much different than your wheat field weeds have likely seen. This is great for resistance management. Zidua’s strength is control of foxtails, but with labeled rates in wheat it only gives suppression. It also gives some suppression of Italian ryegrass, rattail fescue, annual bluegrass, wild oats, and a number of small-seeded broadleaf weeds.
Like Pre-Pare, the rate of Zidua you can safely apply varies slightly depending on soil factors. While pH doesn’t have a huge effect on Zidua, soil type and organic matter does. Higher rates can and should be used for heavy clay soils with higher organic matter levels than what you would do in sandy, low organic matter soils. Zidua can be lightly incorporated or left on the soil surface in no-till.
Group 14 – Sharpen
While Sharpen is not cheap and doesn’t control grass, it is a very nice soil residual broadleaf product with great burndown properties. It is the best residual kochia product available and does very well on most broadleaf weeds. The exceptions are henbit, dandelion, and Canada thistle, where it only provides suppression. Sharpen can be lightly incorporated or left on the soil surface in no-till.
Please read and follow all labels as they may vary from state to state.