Six years ago, Pork & Plants of Altura, Minn., like many family-owned greenhouse businesses, began looking for alternative solutions to traditional controls after younger family members began spending time at the business and conventional methods became less effective. Long, 12-hour days also left the Kreidermacher family with fewer chances to spray. Environmental consciousness combined with the search for long-lasting, practical applications led Pork & Plants to adopt biological controls.
Co-owner Maria Kreidermacher explains how biocontrols became a necessity, what growers should look for in suppliers and how to go about assimilating them into application methods.
Q: In what types of greenhouse structures are you using biocontols?
Kreidermacher: We’re primarily using biocontrols in our open-air production range and traditional roof-vented Agrotech retail greenhouse. We’ve found that if we keep bugs under control prior to sending plants to our hoop houses in March/April, there are enough natural predators to keep up until the plants sell in May/June.
Q: Who are your suppliers for biocontrols?
Kreidermacher: Depending on the product, we’ve used a number of different suppliers: Becker Underwood, Biobest, Bioworks, Syngenta, Natural Industries, and we recently started with Koppert. We’ve definitely seen differences with the quality of the beneficials from one supplier to another (most of them have certain bugs that they are better at), but we’re also trying to find a supplier with customer service to work with us, rather than just take orders. We were ready to give up on the beneficial bugs four years ago, but another grower convinced us to stick with it. Unfortunately, it’s been a long and costly learning process, which would have been more successful and less costly with a better supplier partner.
Q: What are your application methods? Do you use sachets or any equipment?
Kreidermacher: We still use Dramm sprayers for many of the biocontrol products and, after years of trial and error, finally settled on a Dosatron cart to apply the nematode drenches. Most of the beneficials come in shaker cans that we manually sprinkle throughout the crops. We’ve started using sachets on our basket crops, but these need to be applied early and often enough to be preventative.
Q: What pests are you controlling with biocontrols? Which aren’t well controlled with biocontrols?
Kreidermacher: We used to have major problems with aphid outbreaks until we started a banker plant system over a year ago. Spider mites have been relatively easy to control with beneficials, while the biggest challenge in the spring has been thrips. What we’ve learned is that there’s not one single solution, but we had great thrip control in spring 2013 by using nematodes, several types of beneficials, banker plants and supplementing with other biocontrols (especially products like Botanigard for veggies).
Whitefly, on the other hand, has been impossible for us to get control strictly with biocontrols the past two years. We believe part of the problem is we didn’t anticipate a whitefly problem since we hadn’t had anything for four years. So when we brought cuttings in May for standards and trees, we didn’t have a plan in place; so the whiteflies were out of control by July when the rest of the cuttings arrived, and we finally had to resort to harsher chemicals by September. This year, we’re working with a new supplier to put a program in place the minute poinsettia cuttings arrive to prevent having the same situation.
Q: Have you had to come in with traditional controls to fight outbreaks on a regular basis?
Kreidermacher: Previously, when we treated beneficials as curative, rather than preventative, we had lots of outbreaks that forced us to fall back to traditional controls. For the past two years, we’ve only had to resort to traditional controls for whitefly outbreaks in late summer/fall.
Q: What are the challenges of using these control methods?
Kreidermacher: There isn’t one single product to control each problem, and getting help to find the right mix has been a challenge. There are more options for products and suppliers now that hopefully can help you put together a plan. It’s not cheap, especially if it isn’t working and you have to spray costly chemicals anyway. The biggest challenge is accepting that you have to plan ahead, since you can’t be reactive in the application of beneficials or you will end up resorting to traditional controls in the end.
Q: What resources do you use when you have questions or problems?
Kreidermacher: Supplier websites have been a great resource, but there is more information in the industry now than when we started, including magazine articles. Last year’s Ohio Short Course had lots of good sessions. We’ve also asked other growers and gotten some of the best recommendations (like the Dosatron cart for nematodes and a new beneficial supplier). I think we’ve finally found a supplier with sales/product reps that will be more helpful in planning ahead and giving us options; so we can decide what makes the most sense for us in keeping control and staying financially practical.
Q: Any tips or advice to others using biocontrols? Advice on products or processes?
Kreidermacher: Talk to many growers who are currently using biocontrols to get advice on which suppliers/products they use and why. Find a supplier to partner with you rather than just take orders. As I was told previously, don’t give up, you can make it work!