As I’ve discussed before, the natural enemies that provide biological control of pests include both larger creatures (like insects, mites, and nematodes) and microorganisms (fungi, bacteria, and viruses) that combat pests in a variety of ways. Microorganism natural enemies are regulated as pesticides (one type of biopesticide), while the larger natural enemies are not. Growers who are successfully using biocontrol insects, mites, and nematodes usually recognize that they need to apply pesticides in such a way that they are compatible with the biocontrol organisms they use. Take a look at my April post for a summary of online resources that can help you check compatibility of pesticides (including biopesticides) with natural enemies.
Some of these compatibility resources include information on the effects of pesticides (and biopesticides) on bees. Pollinators (including honey bees, lots of other bees, and some non-bees) are very important beneficial insects. You may have noticed that they have found their way into several of my blog posts. So, I wanted to let you know about a brand new resource (hot off the digital presses) to help you protect pollinators.
It includes information not only on pesticides used alone, but (when available) on synergistic effects when multiple pesticide active ingredients are used together. When you combine some chemicals (either in the tank or in the environment) the mixture is more toxic than both chemicals alone.
Where available, it summarizes pesticide toxicity to other bees besides just honey bees (e.g., bumble bees and solitary bees). You can read more about why this is important in this recent article.
It describes what we know about sub-lethal (in other words, negative effects on the bees that are less serious than death) effects of pesticides on bees.
It includes about half a dozen biopesticide active ingredients.
You might be asking: If a chemical on this table is toxic to bees, will it also be toxic to the insect and mite natural enemies I am releasing or conserving on my farm or in my garden? I wish I had a definitive answer to that. As you can see from the nearly three pages of Literature Cited at the end of this document, collecting these data is a time-consuming process. For now, stick with the compatibility resources that are already available, and ask the companies you buy from (pesticides or natural enemies) about compatibility.
In closing, a huge amount of work went into this resource to summarize so much useful and current (as of October 2018) information in an easy-to-read table. Bravo to the authors! The Pollinator Network @ Cornell has other helpful resources for growers on protecting pollinators. Winter is a great time to make plans for using IPM and protecting the pollinators and natural enemies that are so good for the crops we grow!
Quantify what biofungicides add to management of cucurbit powdery mildew and white mold in terms of…
– disease control
– plant health
– economic value (comparing yield gains to fungicide costs)
Evaluate the utility of NDVI (normalized difference vegetation index) as a measure of plant health and disease detection in fresh vegetables
Why this project?
For both diseases (cucurbit powdery mildew and white mold), we’re considering biofungicides used with other pest management – other biofungicides, conventional chemical fungicides, and/or cultural practices. Biofungicides are not expected to be silver bullets, and they work best when used in an IPM strategy. But when deciding whether or how to use them in your operation, it’s good to know what value you’re getting for the extra costs of purchasing and applying the products. This summer we ran trials in three major vegetable-producing regions of the state: western New York, eastern NY, and on Long Island.
Biofungicides for cucurbit powdery mildew
For combatting cucurbit powdery mildew, we’re comparing three biofungicides: LifeGard (Bacillus mycoides isolate J), Regalia (extract from the giant knotweed plant Reynoutria sachalinensis), and Serifel (Bacillus amyloliquefaciens MBI 600). All three were applied weekly starting when the plants were small. Then, when the first signs of powdery mildew showed up, we started a rotation of conventional fungicides (Vivando, Quintec, and Luna Experience). These three treatments plus a rotation of all-organic fungicides (LifeGard, MilStop, Serifel, and a mineral oil) are being compared to two control treatments: the conventional fungicides alone, and plants that received no treatment for powdery mildew. We ran the trials on a variety of bushing acorn squash (‘Honey Bear’) that has intermediate resistance to powdery mildew.
Biofungicides for white mold
In the white mold trial, we’re looking at Double Nickel (Bacillus amyloliquefaciens strain D747) alone or in combination with Contans (Paraconiothyrium minitans strain CON/M/91-08; formerly Coniothyrium minitans). Next year we’ll look at these biofungicides in combination with reduced tillage at one site. Reduced tillage is another IPM strategy for white mold. The active ingredient in Contans is a fungus that eats the resting structures (sclerotia) of the fungus that causes the disease white mold. Because of this, it needs time to work, and is applied either in fall or spring. The goal is to reduce the number of sclerotia present in the next crop. Next year we’ll collect data on whether application of Contans reduced disease. In the meantime, during the 2018 growing season treatments we tested were Double Nickel, Cueva (an OMRI-approved copper) and no treatment for white mold on snap bean. Previous research by the EVADE Lab at Cornell AgriTech at The New York State Agricultural Experiment Station, Geneva, New York, has shown that Double Nickel is a promising biofungicide for white mold.
What is NDVI, anyway?
In a nutshell, the “normalized difference vegetation index” (NDVI) is a way to quantify how much healthy, green foliage is present. The device we used emits different types (wavelengths) of light (red and near infrared), and measures how much of each type of light is reflected back from the leaves of the plant. Leaves that are dark green and healthy reflect more infrared light and absorb a lot of red light. Less healthy leaves reflect less infrared light. A NDVI value closer to 1 indicates healthier plants. A NDVI value closer to 0 indicates less healthy plants (or more bare ground).
Help us quantify the health of plants. Even though NDVI is not a measure of disease, we would expect to see more healthy foliage if biofungicides are contributing to disease control.
Provide some preliminary data to help us determine whether NDVI measurements could be useful to NY fresh vegetable growers.
Field meetings were held at each powdery mildew trial location so that local growers could see the trials and hear about the project. We’re currently wrapping up data analysis from the 2018 field season. You’ll be able to learn about results from the first year of this two-year project at winter meetings around NY, in extension newsletters, and here on this blog. Also, stay tuned for Part 2 of this post with details about how these biofungicides work (modes of action), and how to use them most effectively.
This post was written by Amara Dunn (NYS IPM), Sarah Pethybridge (Plant Pathology & Plant-Microbe Biology, School of Integrative Plant Science, Cornell University), and Darcy Telenko (Department of Botany & Plant Pathology, Purdue University).
Are mosquitoes bothering you while you enjoy summer in your backyard? An IPM approach is definitely the way to go. Start by checking your yard to see where water might be standing. It could be in toys, flower pots, tarps, wheel barrows, gutters, bottle caps, or so many other places you may not have noticed. Removing standing water from your yard takes away places where mosquitoes breed. Less mosquito breeding, fewer mosquitoes. Always think prevention first when you’re addressing a mosquito problem. Read more about mosquito IPM on the Think IPM Blog and What’s Bugging You?
If there are still some containers you just can’t empty (for example, a lined garden pond), you can find some biopesticides (remember, some biopesticides are biocontrols, too!) in your local garden center to help you with your mosquito IPM. Just make sure you follow all instructions on the label of any product you buy. Read all about mosquito biocontrol on this new fact sheet.
And, if you want to learn so much more about IPM for both mosquitoes and ticks, you still have a little time to register for the 4th Annual NYS IPM Conference on Integrated Management of Ticks and Mosquitoes. But hurry – the conference is August 7th!
If you were going to tank mix chemical pesticides, you would of course read the label to check for compatibility before mixing products. The same concept applies when using living organisms for pest control. Whether you are using parasitoid wasps, predatory mites, microorganisms, or nematodes, you need to know whether your biocontrols are compatible with each other and any other pest management products you plan to use. For example, a biocontrol fungus might be killed if you tank mix it with (or apply it just before) a chemical fungicide. Insecticides (whether or not they are biological) could be harmful to natural enemy insects and mites. Even some beneficial insects are not compatible with each other because they may eat each other instead of (or in addition to) the pest.
It’s a good idea to keep an updated list of the products and organisms you plan to use for pest management, and their compatibility with each other. For biopesticides (remember the difference between “biopesticide” and “biocontrol”?), start by reading the label (see label excerpt below). You must follow all instructions you find there. Many manufacturers also provide lists, tables, databases, or apps to help you find compatibility information (some links at the end of this post). This is especially useful for insect, mite, and nematode natural enemies, which are not pesticides and do not have pesticide labels. When possible, obtain compatibility information from the manufacturer or supplier you will be using. Different strains of the same microorganism or nematode may have different sensitivities to chemicals.
Remember that NY pesticide labels (including biopesticide labels) can be found through the NYSPAD system.
Below are some links to resources from several manufacturers and suppliers of biocontrol products. No endorsement of specific companies or products mentioned in this post is intended. If you know of a link to additional information that is missing, please let me know so that I can include it!
Beneficial nematodes from BASF – This chart describes compatibility of beneficial nematodes sold by BASF with natural enemies and pesticides. Note that only the genus name of each “biological” active ingredient is listed, and that over time, the names of some predatory mites (and whether they belong to the genus Amblyseius or Neoseiulus) have changed.
Biobest Side Effect Manual – This side effects manual is available either as an interactive website, or as an app. Choose pest management products by active ingredient or name of the commercial product (including the biocontrol microorganisms Beauveria bassiana and several types of Bacillus thuringiensis). The list of “beneficial organisms” to choose from includes bumble bees and nematodes, but not beneficial microorganisms (fungi, bacteria, and viruses). Select active ingredients/commercial products and beneficial organisms from both lists, then use the legend to interpret the compatibility information that is generated.
Koppert Side Effects Information – This information is available either as an interactive website, or as an app. Select beneficial organisms of interest (by either the Koppert product name or the Latin name). Select one or more “Agents” (pest management products) by either the trade name or the active ingredient. Click on Results, and use the Legend to interpret the output.