Soybeans planted in the first half of April or earlier have been proven to yield 10% higher than soybeans planted in late April or early May, but not without risks*. Early planting exposes the seed to harsher conditions – cold soil, limited sunlight and new pests. Slugs, in particular, are a pest that pose challenges to early planted soybeans.  

Slugs are made up of 80% water, so they’re most active when the air is humid, sunlight is limited and temperatures are below 70 degrees Fahrenheit. In other words, these slimy pests thrive in the cool, damp conditions of late March and early April. Growth of early planted soybeans often gets off to a slow start, and because slugs can feed directly on the seed or seedling of soybeans, it creates a perfect storm for slugs to cause varied emergence, decreased stand and even plant death.

Preventing Slug Damage

Crop residue increases cool, damp conditions for slugs to thrive. Use fall tillage to ensure residue is decomposed before spring planting. Less residue in the field will leave slugs exposed to more sunlight, increasing their chances of desiccation (drying out).

If fall tillage isn’t an option, salt is effective at speeding up the desiccation process and decreasing slug activity. Consider applying a salt-based fertilizer, like potash, to decrease slug populations. Keep in mind, the slug must come in contact with the salt for it to take effect. If slugs aren’t active or don’t contact the fertilizer, it won’t cause desiccation. The same goes for if a heavy rain shortly after application dilutes the salt – the fertilizer won’t have any effect on slug activity.

A safe guard to protect your soybeans from slug damage is to ensure your bean rows don’t land on top of a corn stalk row from last year. Plant two 15-inch bean rows between 30-inch corn stalk rows from last year.

It’s no secret that we’re obsessed with yields that win. Creating an environment where the seed can reach it’s full genetic potential is critical for high yields. Our agronomic experts stand ready to grow with you. Whenever you’re ready, let’s talk seed.

*Data from AgriGold trials of G3520RX comparing plots from NE, KS, IA, MO, IL, IN, OH, KY, TN, AR and NC with planting date of before April 15 compared to planting date of April 15 to May 15.

Sources

AgriGold. 2022. Soybean plot data. Get the data.

Lee, Chad. 2017. Slugs in Soybeans. https://www.kygrains.info/blog/2017/5/31/slugs-in-soybeans

Dean, Ashley. Hodgson, Erin. 2020. Management Considerations for Slugs: Do Insecticides Work?. https://crops.extension.iastate.edu/cropnews/2020/03/management-considerations-slugs-do-insecticides-work