Harvest Desiccants—Your Answer to Harvest Worries

During soybean harvest weather, weeds and wetness will all make farmers weary. When these problems threaten the efficiency of harvest and the quality of a soybean crop, consider using a harvest desiccant to get your crops out of the field in a timely manner.

Desiccants can help accelerate harvest by killing green tissue on soybean plants, as well as green weeds. Use the following as a guide to understand desiccants and how to use them most effectively on your farm.

HOW DO I KNOW IF I SHOULD USE A DESICCANT?

Consider using a desiccant if any of these conditions exist in your fields:

  • If there has been a weed resurgence before your soybeans have matured.
  • If pods are mature and ready to be harvested, but leaves and stems are still green.
  • If weed density is high enough to increase soybean seed moisture and damage soybean seed.
  • If weed density is high enough to increase the amount of foreign material in harvested seed.
  • If weed density will decrease your harvest speed or efficiency.
  • If wet weather will significantly delay harvest.

Harvest desiccants should not be used if:

  • Weeds emerged late in the growing season and will not interfere with harvest.
  • Weeds will not produce mature seeds that will contaminate the grain.
  • If the desiccant can’t be applied in time to ensure targeted weeds are dry and harvest aid label restrictions are met.

When using desiccants it is also important to keep in mind that:

  • Drought-stressed weeds will not be desiccated effectively.
  • Adding sodium chlorate to a desiccant will help remove excessive moisture from green soybean tissue and/or seed.
  • Soybeans should be harvested as soon after desiccation as allowed by the label.
  • Desiccants should not be applied just before a rain, if possible.
  • Desiccants do not impact yield when applied after seeds are mature. However, they can result in better seed quality and allow for earlier harvest and increased harvest efficiency.

WHEN SHOULD I APPLY A HARVEST DESICCANT?

Timing is crucial when it comes to applying a harvest aid to a crop. If a desiccant is applied too soon, it can reduce overall yield because pods may not have enough time to mature fully. Yield can also be adversely affected if a harvest aid is applied too late as mature pods can shatter.

According to Mississippi State University Extension Service, harvest desiccants should be applied when 70 percent of the leaves have fallen from the plant and/or when at least 65 percent of the seed pods have reached a mature brown color. To determine the percentage of leaves that have dropped, divide the number of nodes from which the leaf has fallen by the total number of nodes on the plant and multiply that number by 100. For example, suppose a plant has 14 nodes missing leaves and a total of 20 nodes. Divide 14 into 20 and multiply by 100, which indicates 70 percent leaf loss.

FOR MORE RESOURCES ON DESICCANTS VISIT:

Mississippi Soybean Promotion Board website: www.mssoy.org and search for harvest desiccants.

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