We are hitting the middle of August, which means that our main focus for inputs will be turning from our corn and soybeans to our double-crop beans. Double-crop beans are a very useful and relatively low-cost way to utilize our wheat fields once the wheat has been harvested. Generally speaking, a farmer will no-till plant soybeans straight into wheat stubble, which sets aside the need for tillage. The farmer will have usually already put enough fertilizer ahead of the wheat to account for the following double-crop beans. At this point, the main concern with double-crop soybeans is controlling the weeds.
Know your Soybean’s Resistant Traits
When it comes to controlling weeds in double-crop beans, you must first take into consideration what your soybean’s herbicide resistant traits consist of. If you wish to use a dicamba-based product such as Monsanto’s Xtendimax, then you will need dicamba-resistant beans. The same logic applies to Liberty, Round-up, 2,4-D, and so on. Once you have determined what your soybeans can handle as far as herbicides go, then you can start to make a plan as to when it is best to spray your new soybeans.
Use a Residual
When planning on when to spray your beans, you’ll want to have an idea as to whether you want to make two passes across your double-crop beans or just one. Since double-crop beans mature much faster and typically don’t yield as much as single-crop beans, farmers typically don’t do more than one pass of herbicide unless significant weed threats pop up in the future. If you plan on making only one trip, you will definitely want a residual herbicide to keep weeds from emerging for as long as possible while the soybeans mature. The best weed is one you never see, and the only way to never see a weed is to use a herbicide specially designed to keep them from emerging.
One factor you will want to consider when using a residual herbicide is the carry-over effect. Some residual herbicides remain active in the soil for a long-enough time to affect next year’s crop. For example, if using a product like Syngenta’s Prefix (which contains fomesafen) in your field, then you will need to be wary of how late you apply it and what crop you will be planting there next year. If you are planting corn in said field next year, you may see some fomesafen damage to your corn from applying too late the previous year. This is especially true for double-crop soybeans, as you will be applying such products late enough in the season that it will definitely have some carry-over threats. You can avoid such concerns if you are planting soybeans in that field the following year, which is common practice following wheat and double-crop soybeans.
Grass
Grasses will be one of your most common foes when controlling weeds in double-crop soybeans. Since your soybeans are following wheat, it can be assumed that you will be seeing a significant amount of volunteer wheat if left unchecked. Other grasses may be hiding amongst the crowd as well. Make sure to add a clethodim-based herbicide or another grass controlling type herbicide to manage your unwanted grasses before they spread and overrun your fields.
Timing
Timing will be a big factor when planning your herbicide application in double-crop soybeans. You will likely want to hit your soybean plants early, before they emerge. By doing this, you stand the best chance of eliminating all the current weeds in your fields and preventing new emergence for a good portion of the double-crop soybean’s lifespan. Sometimes, a herbicide cannot be applied before soybean emergence, in which case it is still best to apply a residual and clean-up herbicide as soon as possible. You will want to eliminate any competition to your soybeans as soon as possible so they can be given room to grow. Keep in mind that if you are spraying your beans after they emerge, then you may have to consider which herbicide you use. Many burndown or early residual herbicides will cause significant damage or even kill your soybeans if they make direct contact with them.
Conclusion
Double-crop soybeans are a good way to finish out the season if you planted wheat earlier on, but they still need some maintenance just like every other crop. It is important to know what you are doing and what tools to use when choosing the best methods of controlling weeds. Luckily, you don’t have to decide how to proceed with weed control in double-crop soybeans on your own. Service and Supply Cooperative is uniquely suited to find the best solutions for you and your fields. We have seasoned experts on staff ready to consult you on which products are best for your fields. We also have a field-scouting service that helps to determine what is happening in your fields and how best to deal with it. Service and Supply has all the herbicide products you will need to handle your double-crop soybean pests. To get in touch with us about any of our products or services, use one of the contact links below.
