Efforts to make them stronger and live longer are underway
The next frontier of crop protection is a set of living, breathing bodyguards collectively known as biologicals. For years, rhizobia inoculant to improve nitrogen fixation in soybeans was the mainstay in biological protection. More recently, numerous other products have entered the market.
Now that they’re here to stay, manufacturers are working on making biologicals better, stronger and longer-lasting. The reason is obvious—a living layer of protection does no good if it comes to the farm dead on arrival.
According to researchers such as Jennifer Riggs, SeedGrowth product development manager for Bayer, “fitness” is a concept becoming important for biological manufacturers.
“Bayer does years of testing in laboratory, greenhouse and field testing to assure our products are viable across a wide range of temperatures and soil types,” she says. “If we are developing a seed treatment, we will do research to understand the fitness of that product across the multiple geographies that crop encompasses.”
Riggs says there are a variety of stabilizers and growth enhancers to help maintain and extend the shelf life of biological products.
“These additives are proprietary to the manufacturers, but the most important item is for growers to follow their recommendations,” she says.
Efforts to extend shelf life are already showing dividends, says Justin Clark, technical market specialist for BASF. “Not long ago, we were talking about 30-day on-seed survival,” he says. “Now, we’re up to 125 days or more on most active ingredients.”
Different formulation and fermentation practices help provide a food source for the bacteria that will give it a booster shot once it is reactivated in the soil environment, he adds.
Also, different types of bacteria have different levels of stability. For example, Bacillus bacteria form spores that can exist for months or even years in a dormant state. Used as a seed treatment, biologicals that include Bacillus are relatively hardy. Want to activate the spores? Just plant the seeds. Rhizobia bacteria, in comparison, offer no such spore formation and are therefore more susceptible to extreme heat differences.
Seeds treated with biologicals, which are living organisms, require gentle handling and storage.
No matter what biological you’re using, handle it with care, Clark says. “There’s a tremendous amount of carefulness that goes into manufacturing some of these products,” he says. “For example, the rhizobia packaging areas are often as sterile as hospital operating rooms. Fermentation is an in-depth process with a lot of parts to it to get the high concentration we want to put on each seed or in the furrow.”
What about on-farm handling? Riggs says Bayer seed treatment biologicals are stable as long as seed is stored in conditions that assures seed viability.
Year-round storage could prove risky at the retail or farm level, Clark adds, especially with Rhizobia products, which are less able to with-stand temperatures outside the range of 40° to 77°F.
“Anything beyond that will cause die-off, and most warehouses in the Midwest will see storage temperatures fall outside that range at some point during the year,” he says. “If you’re transporting them, don’t leave them in a truck with your windows up on a hot spring day, and try to keep them out of direct sunlight.”
Clark says farmers should give acres treated with rhizobial inoculants like Vault HP plus Integral a midseason health inspection. It can be hard to pinpoint seed treatment effectiveness above ground, but look at the general health of the plant—especially if you incorporated an untreated check in your field for comparison.
Farmers who use a soybean inoculant can conduct a more specific ground truthing process, Clark adds. Dig up a few plants at the R1 stage and investigate the nodules present along the main tap root. Break a few open—if they’re a reddish, pinkish color that means they’re actively fixing nitrogen, he says.