Much research has been done demonstrating the efficacy of biocontrol products to control a variety of pests and diseases, but the best way to evaluate whether or not it will pencil out for your operation is by diving in and conducting tests that allow you to see visible results.
Here are seven key points to keep in mind to help guide you in your decision to use biocontrols.
1. Plot Test
According to Dave Peck, General Manager of Manzanita Farms in Santa Maria, CA, the first thing any grower should do before deciding to use biocontrols is a side by side test using biocontrols versus traditional control measures to determine efficacy.
“Depending on the type of biocontrol you’re considering, the size of the test could vary based on a few beds to a few acres,” he explains. “If you’re using an insect or a mite that walks around, you have to have a pretty-good-size plot in order to make sure you’re counting the effectiveness of that biocontrol agent because they do move around quite a bit.”
Peck farms on more than 350 acres of both organic and conventional strawberries, and is currently using Bacillus bacteria for larval worm control as well as two species of predatory mites for two-spotted mite control, which have both proved to be consistent in his fields.
Traditionally, he has tested biological controls on his strawberry crops for three years before deciding to incorporate any products into his rotation. Biological organisms are largely affected by weather, and the three-year period allows him to see how the products operate under a variety of conditions.
“Temperatures and humidity levels are extremely important for some of these biocontrol agents, and sometimes you have to experiment for a few seasons to learn exactly what your thresholds are for your particular crop in your particular area,” he says.
2. Scout For Pest Populations
Another key factor in the decision to use biocontrols comes down to scouting, Peck says. It can help track the population of your pests to better determine which type of control measure to use, and ultimately whether or not biocontrols may be necessary.
“You’ve got to be able to know exactly what the true population of your pests are, and maintain a very consistent program all season long so you know when things start to get out of hand before it gets too late,” he says.
After you’ve applied your biocontrol, scouting for pest populations can help you understand when you’ve put out enough, when it’s time to be patient and wait for results, and when it might be time to apply more.
3. Evaluate Your Cost/Benefit Analysis
Because the cost of biocontrols is traditionally higher than most conventional crop protection products, making sure the benefits of these products outweigh the costs should be paramount in your decision to use them.
“If you have a really good scouting program, you can track the history of your pest populations during the season. For example, if you can see that your miticide bill is equal to or lower than it was before, and your two-spotted mite populations remain below economic threshold, then you can be reasonably sure you’re moving in the right direction,” he says.
4. Consider Your Crops
The type of crops you grow is going to make a huge impact on your decision to use biocontrols, Peck explains.
“Every crop is going to lend itself to use one biocontrol or another; a lot of that depends on what kind of pests you’re dealing with,” he says. “The main question to ask is, does that crop afford the correct environment for that biological organism to feed and reproduce?”
5. Evaluate Your Materials
Make sure you’ve properly assessed which biological materials are appropriate for your crops and mix well with other chemicals you’re using, as some traditional crop protectants can kill biological agents, Peck says.
Unfortunately, he discovered this the hard way after using sulfur to control powdery mildew in his strawberry crop, which led to a complete decimation of his predatory mites.
“We ended up having to use something more expensive to control mildew, but in the end it was less detrimental on the predatory mites. That was probably the hardest lesson we had to learn,” he says.
Fortunately the damage was not permanent, and he was able to reinoculate his field with predatory mites to get the populations back up.
“I think a lot of growers have trouble because sometimes they have to give up something very economical because it hinders their biological control, but in the long run they save money by using biological controls. Sometimes that’s a tough bridge to cross,” he says.
6. Get Expert Advice
The manufactures of biocontrols should be your primary point of contact if you have any questions about usage, Peck says.
“There is less industry-wide data available than for chemicals, but the people who manufacture the materials are going to have more experience than just about anybody. They’ll know if you should try it, or if they think it might not be effective,” he explains.
After that, Peck suggests contacting a farm adviser who has direct experience working with biocontrols, Pest Control Advisers (PCAs), or even other farmers who have experienced success — or failure for that matter — with the products you’d like to use.
7. Be Patient
The wide variation in temperatures that you may see in one season or even between seasons may mean a significant amount of time before you see results from your biocontrol products.
“Something may work wonderfully one season, and the next season you see nothing at all. And that’s just a normal part of the process,” Peck explains.
It’s important not to get disheartened if you don’t see results quickly. Peck says to be persistent and patient with your testing because the results you’re looking for may be just around the corner.