The benefits of pre-harvest.
There are two primary reasons to apply a pre-harvest herbicide. The first is for weed control. Hard-to-control perennials such as Canada Thistle and Quackgrass are best controlled during the fall when leaf area is at is maximum. This is the primary reason pre-harvest should be considered in crops such as cereals with crop staging being critical.
For wheat, preharvest application can only occur when the crop is at 30% or less moisture content. This is usually three to five days before you would normally swath. At this stage, if you press the kernel with your nail it will leave a dent in it.
For complete details on preharvest use in wheat and other crops, see the Keep it Clean link below.
The second reason to apply pre-harvest herbicide is for crop dry down. Certain pre-harvest products like diquat and Heat will help dry out the plant and accelerate the overall maturity and harvesting process. It can also help mitigate uneven crop growth and control weeds. It’s important to note that glyphosate is not to be used for desiccating purposes. Not only is it ineffective, (takes over two weeks to dry down) but it gets absorbed by an immature crop which leads to residues in the grain.
Summary of where pre-harvest products are allowed.
|Barley||Yes||Malt – Consult with
grain companyFeed – Yes
(Red lentils only)
|Cereal Seed Crops||No||No||No|
Talk to your Grain Buyer
When considering pre-harvest products like glyphosate, Heat or diquat, it is important to pinpoint what exactly you are trying to accomplish, and in which crops. It is very important to check the declarations of grain buyers to see if they will accept grain treated with certain products. P&H will work with you through these considerations and help you pick a product that will meet your operation’s needs.
Visit your local P&H retailer to learn more about pre-harvest products and the considerations you should make when using them. Our team of experts is ready to help.
For complete details on pre-harvest products by crop, visit Keep it Clean.