In today’s soybean production system, the use of harvest aids for field uniformity has become a growing practice.
Soybean desiccation: FAQs
Across the south, this practice has been extensively utilized for several years. However, in some areas, soybean desiccation may not be as prevalent as in others.
Regardless of familiarity, every year we revisit the topics of:
- What product do I need to use?
- When do I need to apply it?
- Why do I need to use harvest aids?
Unlike many of the other practices we have with soybeans, the options for “what products do I need to use” are fairly standard across the board and uniform within much of the region (Table 1). Products in Table 1 act as harvest aids to help uniform soybean maturity as well as improve harvest efficiency.
What are the tradeoffs between different harvest aids?
With each harvest aid product comes different tradeoffs. Paraquat (Devour®) is one of the most widely used and recognized harvest aids and is often the most cost effective. However, the tradeoff is, that it has the longest preharvest interval (PHI) of any other options.
Saflufenacil or carfentrazone (Strevin™ 2EC) may be more costly, and sometimes require two applications, but have a very short PHI (Table 1). To ensure maximum defoliation, the use of a high-quality MSO, COC, or NIS is recommended.
Factors affecting harvest aid
Choosing what harvest aid products to use typically depends on to following factors:
- Cost effectiveness
- Harvest plan
- Weather patterns
- Harvest efficiency/capacity
Worst case scenario is applying a harvest aid to an almost mature crop and have a PHI that gets them caught in rain or weather pattern.
Additionally, harvest equipment availability and capacity is of top priority to consider. There’s no turning back the clock once harvest aid applications have been made and delaying harvest can lead to yield losses.
When do I apply my products?
Once a harvest aid has selected a product or a plan for a harvest aid the next question is when do I apply it? Research conducted in southern soybean producing states identifies R6.5 (seed separated from the protective membrane within the pod in the upper four nodes) as the minimum growth stage to begin applying harvest aids (Figures 1, 2, and 3).
Figure 1, 2, and 3: Soybean differences in R6 and late R6.5 soybean growth stages. Figure 1 shows soybean closer to R6 growth stage in which seed have completely fill the pod with squared off margins and white membrane mostly intact. Figure 2 are soybean closer to late R6.5 demonstrating full membrane detachment from seed.
Applications made prior to R6.5 can cause damage and yield loss (Table 2 and 3). Additionally, each product may have specific requirements and specifications for exact timing (Table 1).
Table 2 and 3: Soybean grain yield following desiccant application at different growth stages.
Why do I need to use harvest aids to desiccate soybeans?
There are several benefits to using harvest aids as mentioned above (harvest efficiency, farm management, etc). However, a couple additional reasons are:
- Risk mitigation
- Uniform maturity
- Minimize weed pressure impact to harvesting
- Early contract delivery
Consider that off-target movement of these products and applications can have serious impact on neighboring crops such as rice. Data generated through Mississippi State University indicated that rice yields were affected all the way up to 7 days prior to harvest from simulated off-target harvest aid applications.
The Takeaway
When harvest is around the corner, consider what a harvest aid can offer your farming operation. Please consult any of your local Agronomic Sales Enablement Team members or your local Simplot Grower Solutions Crop Advisor to answer your application questions.
Authors
Connor Ferguson, Texoma
Justin McCoy, Southwest
Ben Lawrence, Bayou
Jeffrey Mansour, Midsouth
