Tag Archives: biocontrol

Harvesting and sowing your own native seeds – August 17, 2023

Pink echinacea and bright yellow goldenrod flowers
Echinacea and goldenrod are just two species of native perennial wildflowers that feed beneficial insects.

For the past six years, we’ve been cultivating perennial grasses and wildflowers that feed and support beneficial insects. All of these plants came from seeds—whether sown by us or by others—and we’ll focus this year’s annual open house on these wonderful seeds.

Come join folks from New York State Integrated Pest Management, and Petra Page-Mann from Fruition Seeds to talk about how we harvest, clean, store, and germinate seeds of perennial wildflowers that support beneficial insects. Stop by our open house between 3:30 and 6:30 p.m on Thursday, August 17. We’ll offer guided explorations of our established plots of perennial wildflowers and grasses at 3:45, 4:45, and 5:45 p.m. You are also welcome to explore the field on your own, or browse our interactive resources on display. There will be a few hard copies of resources available at the event, and we’ll continue to add digital resources to this folder up to and following the event. Everyone will go home with seeds of native perennial plants that support beneficial insects.

No registration needed for this free event. Find all the details at our event page. When you arrive at the entrance to the farm, look for signs with the pink echinacea flower and the Christmas tree on them, and follow the signs to our field.

Graphic of pink echinacea flower, Christmas tree, and the NYSIPM logo
Follow these signs to find our field!

Funds for this project were provided by NYS Dept of Ag and Markets and the USDA National Institute of Food and Ag.

Managing tomato bacterial diseases? Biopesticides could help

Are you using copper to protect your tomatoes from bacterial diseases? Research from Cornell suggests that you could replace some of those copper applications with a biopesticide.

Two pictures of tomato leaves showing small brown specks, and larger specks or groups of specks surrounded by yellow margins
On tomatoes bacterial speck and spot both look like small black spots which may develop yellow halos around them as the lesions age.

Preventing bacterial diseases on your tomatoes starts with good integrated pest management practices.

  • > 3-year rotation out of tomatoes and peppers
  • Clean seed or disease-free transplants
  • Heat treat seed (unless it is pelleted or treated)
  • Good sanitation in transplant production facility (e.g., new flats or sanitize between uses, sanitize greenhouse after each season)
  • Inspect transplants and destroy any with symptoms of bacterial disease
  • Do not work in tomatoes (e.g., tie, prune) when leaves are wet
  • Either sanitize tomato stakes between growing seasons, or use new stakes each year (preferred)
  • If you have an outbreak, till in plant debris quickly.
Green tomato fruit held in a white person’s hand with four black and brown spots, each surrounded by a white halo
Bacterial canker lesions on tomato fruit

If you are doing all of these things and still need some extra protection from bacterial diseases (e.g., in a wet growing season), pesticides might also be in your IPM toolbox.

In New York, we’re fortunate that so far few bacterial isolates have been found to be resistant to copper. Copper resistance is a major problem in the southern U.S. and we’d certainly like to preserve its efficacy here in NY. Some people are also understandably concerned about the environmental impacts of using a lot of copper on their farms.

Cornell vegetable research programs led by Chris Smart and Meg McGrath have been testing products against our three bacterial diseases – spot (Xanthomonas), speck (Pseudomonas) and canker (Clavibacter) for a number of years. So far, two products – Double Nickel LC (1 qt/A recommended) and LifeGard (4.5 oz/100 gal water) – have been rising to the top. When comparing these products alone to alternating either with copper, both worked better as replacements for some copper sprays than alone. Some research trials only included the biopesticide by itself, but the Double Nickel label states that it should be applied only tank mixed or rotated with copper-based fungicides.

Double Nickel alone (one year of data in Geneva) was as good as copper against bacterial spot. Double Nickel alone (two years of data in Geneva) and LifeGard alternated with copper (one year on Long Island) were as good as copper against bacterial speck. While neither product is registered (legal) for use against tomato canker, in research trials in Geneva, Double Nickel (one year) and LifeGard (two years) alternated with copper controlled canker as well as copper alone. So if you are replacing some copper sprays with either Double Nickel or LifeGard, you’ll likely notice some incidental bacterial canker protection, too.

New to using biopesticides? The New York State IPM Program has a new resource to help. Biopesticide profiles (scroll to bottom of page) for Double Nickel, LifeGard, and seven other products provide information on tank mix compatibility, shelf life, and other practical tips.

Screen shot of a website section entitled Biopesticide Profiles. PDFs of these profiles are available for Actinovate, Contans WG, Double Nickel, LifeGard, Regalia, Serifel, Stargus, Theia, and Timorex ACT
Follow the link in the text and scroll to the bottom of the page to find these biopesticide profiles from the NYSIPM program.

Changes in pesticide registrations occur constantly and human errors are possible. Read the label before applying any pesticide. The label is the law. No endorsement of companies is made or implied.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program, and Chris Smart, Professor in the School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section at Cornell University. Support for this project was provided by the NY Farm Viability Institute.

Logo for the NY Farm Viability Institute

New from NYSIPM: Biopesticide Profiles

Screen shot of a website section entitled Biopesticide Profiles. PDFs of these profiles are available for Actinovate, Contans WG, Double Nickel, LifeGard, Regalia, Serifel, Stargus, Theia, and Timorex ACT
Follow the link in the text and scroll to the bottom of the page to find these biopesticide profiles from the NYSIPM program.

I’m excited to announce that the New York State IPM Program has a new resource – Biopesticide Profiles!

(Scroll down to the bottom of the page linked above, past the efficacy summaries, which are also cool.)

So far, we have profiles for nine biopesticides registered for use on various crops in NY (including one for use in home gardens) against plant diseases. I plan to add more profiles over time, and will definitely add some bioinsecticides in the future.

These profiles are not meant to replace pesticide labels; always read and follow the label and only use pesticides that are currently registered in your state or province. These profiles have practical details about how to use biopesticides most effectively, including information on mode of action, compatibility with other pesticides, best storage conditions, and shelf life. I’ve also included information on any known toxicity concerns for not just bees, but other beneficial insects like natural enemies of pests.

Screen shot of the NYSIPM Biopesticide Profile for Actinovate which contains the active ingredient Streptomyces lydicus WYEC 108 (alive). Other information includes the available formulations, types of pests targeted, the fungicide resistance action committee number, the mode of action, and the best environmental conditions under which to use it.
Just some of the practical information you can find on the NYSIPM biopesticide profiles.

I collected this information from pesticide labels, pesticide manufacturers, EPA registration documents, and peer-reviewed literature, to save you time when you’re considering using a biopesticide. But you should still always read the label.

Take a look and let me know what you think! Which biopesticides should be next on my list?

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. Support for this project was provided by the NY Farm Viability Institute.

Logo for the NY Farm Viability Institute

Biopesticide modes of action

Diagram showing an unhappy-looking caterpillar that has stopped eating a leaf. Blue diamond shapes and pale blue rectangles with smiling faces are also on the leaf.
Biopesticides include microorganisms, plant extracts, and other naturally-derived compounds that control pests.

Biopesticides are one aspect of biological control. The active ingredients in biopesticides include microorganisms (microbes), plant extracts, and naturally-occurring chemicals (like potassium bicarbonate). As a result, some of the ways they control pests (their modes of action or MOAs) are different from conventional, synthetic chemical pesticides. Also, many of them have several MOAs, and not all MOAs apply to all pests listed on the label. If a biopesticide contains live microbes, and especially if its MOA requires the microbes to stay alive on the plant for some period of time after application, this also has important implications for how the product is stored and applied. Understanding the mode of action of a product will help you get the most out of it.

I like to break down biopesticide MOAs into the following categories:

Diagrams - Tiny spores of insect-killing fungi land on the body of an insect, germinate, infect the insect, grow throughout its body, and eventually kill it. Below, a diagram shows blue spores contacting a yellow rectangle with a frightened face, representing a pathogen. The spores grow and kill the pathogen.
Eat – Some biopesticides contain living spores of a fungus (blue). These spores need to land on the insect pest or plant pathogen (yellow rectangle). Then they germinate (like a seed), invade and grow, eventually killing the pest. If the humidity is high enough, the fungus may even produce more spores and spread to other pests.

Eat live microbe grows on/in pest

Biopesticides with this MOA can work against insect pests (e.g., products that contain Beauveria bassiana) or plant diseases (e.g. Contans, which contains Paraconionthyrium minitans strain CON/M/91-08). Many biopesticides with this MOA contain fungal spores. These spores will germinate once they land on the insect or disease-causing pathogen, and may have temperature and/or humidity requirements for germination. Make sure you store the product correctly, confirm compatibility with other products before tank mixing or applying, and apply under recommended environmental conditions.

 

Diagram - A caterpillar eats and is sprayed with a bioinsecticide (blue diamonds), and then dies. Plant pathogens (yellow rectangles) are poisoned by biopesticide microbes (blue rectangles) and the antimicrobial compounds they produce (blue droplets).
Poison – Some biopesticides (blue diamonds or blue smiling rectangles with droplets) work much like conventional chemical pesticides. They directly kill or otherwise inhibit the insect pests (like this caterpillar) or plant pathogens (yellow rectangles with frightened faces) when they contact it or are eaten by it.

Poison – biopesticide (or its products) kills the pest directly

Biopesticides with this MOA can work against insect pests (like products containing Bacillus thuringiensis) or plant diseases (e.g., Double Nickel containing Bacillus amyloliquefacies strain D747, or products containing potassium bicarbonate). Obviously, potassium bicarbonate products do not contain live microbes. Some biopesticides that poison pests do have live microbes that continue to produce antimicrobial products after they are applied. Others work because of the compounds the microbes produced while the biopesticide was being made.

 

Green leaves covered with smiling blue rectangles. Yellow rectangles with angry faces are next to the leaves.
Keep out – Some biopesticides contain microbes (blue smiling rectangles) that grow on the plant. These beneficial microbes use up space and nutrients so there is no room for the pathogen (angry yellow rectangles.

Keep out – live microbe grows on plant, leaving no room for pests

Biopesticides with this MOA can work against plant disease (e.g., Actinovate which contains Streptomyces lydicus WYEC 108, or Serifel, which contains Bacillus amyloliquefaciens strain MBI 600) and may be bacteria or fungi. The microbes in biopesticides with this MOA must be alive when applied and need to be able to grow on the part of the plant that is being protected.

 

Diagram of a plant with blue smiling rectangles on both leaves and roots. Little yellow lightning bolts surround the roots and leaves.
Turn on resistance – Some biopesticides contain microbes (blue smiling rectangles) or other natural compounds that activate the plants defense system, so that it’s ready when it encounters a pathogen.

Turn on resistance – turns on the plant’s defenses before pest attacks

As far as I know, these biopesticides only work against plant diseases, but as new products are developed, or as we learn more about existing biopesticides, this may change. Some examples include Regalia (giant knotweed extract) and Lifeguard WG (Bacillus mycoides isolate J). Some of these products contain live microbes that need to stay alive (like LifeGard), while others do not. These biopesticides need to be applied before infection.

 

Diagram - The plant on the left has no smiling blue rectangles on leaves or roots. The plant on the right has these blue rectangles on roots and leaves and is larger.
Grow strong plants – Some biopesticides contain microbes (blue smiling rectangles) or other natural compounds that enable the plant to grow stronger and healthier. As a result, the plant can better withstand attack from a pest.

Grow strong plants – makes plant stronger, healthier, more resilient

These biopesticides primarily work against plant diseases. Some examples include: Serenade (Bacillus subtilis strain QST 713), RootShield (Trichoderma harzianum), and Sil-Matrix (potassium silicate). Some of these products contain live microbes that need to stay alive, while others do not (e.g., Sil-Matrix). These biopesticides need to be applied before infection.

 

Diagram - One leaf is covered with blue diamonds and smiling rectangles (bioinsecticide), but the other is not. The caterpillar is feeding on the leaf that has no bioinsecticide.
Repel – Some bioinsecticides (blue diamonds and blue rectangles with smiling faces) protect plants because they repel insect and mite pests.

Repel – pest avoids plants treated with biopesticide

Biopesticides with this MOA can work against insect pests, but perhaps only on certain insect life stages. Some products with this MOA could contain live microbes, while others do not. You can evaluate the effectiveness of products with this MOA, not by scouting for dead insects, but by looking for reduced damage or lower insect populations on treated plants. Examples include: Grandevo WDG (Chromobacterium subtsugae strain PRAA4-1 and its spent fermentation products) and products containing azadirachtin.

 

Diagram - A caterpillar eats or comes in contact with a bioinsecticide, and then stops feeding.
Stop feeding – Some bioinsecticides (diamonds and rectangles on the leaf) cause insect and mite pests to lose their appetites.

Stop feeding – stops pest from feeding; pest eventually starves

Biopesticides with this MOA can work against insect pests either by contact or ingestion and may only be effective against insects of certain ages or life stages. It depends on the biopesticide and pest. Examples include insect-killing viruses and some types of Bacillus thuringiensis products. Some products with this MOA could contain live microbes, while others do not. Live pests will still be present for some time after applying a product that works in this way, since the pests die of starvation. Watch for feeding damage to stop or a reduction in insect numbers over time to know if the product is working.

 

Diagram – Three aphids on a leaf, two of which are exposed to blue diamonds. The aphids exposed to the diamonds stay the same size. Another aphid that was not exposed grows normally.
Stop growth – Some bioinsecticides (blue diamonds in this diagram) don’t kill insects and mites outright, but they can prevent them from molting and growing into the next life stage. Pests that can’t move on to the next life stage will eventually die.

Stop growth – stops pest from growing or molting; pest eventually dies

Biopesticides with this MOA may work against insect pests either by contact or ingestion and may only be effective against pests of certain ages or life stage. It depends on the biopesticide and pest. Examples include Venerate (Burkholderia spp. strain A396) and some products containing azadirachtin. Some products with this MOA could contain live microbes, while others do not. Products with this MOA will not kill pests immediately, but will prevent them from growing or molting. Watch for insect populations to decline over time, but do not expect pests to die immediately.

 

Diagram - Two yellow moths surrounded by blue diamonds. A red heart has a line through it.
Stop reproduction – Pheromones (represented here by blue diamonds) are a type of bioinsecticide that confuses insects looking for a mate. As a result, males and females can’t find each other, don’t mate, and females don’t lay eggs.

Stop reproduction – hampers pests’ ability to find a mate or produce eggs

The two main groups of biopesticides I know of with this MOA are (1) pheromones that make it hard for male and female insects to find each other, or (2) products that reduce the number of eggs female insects lay. Grandevo (Chromobacterium subtsugae strain PRAA4-1 and spent fermentation products) is an example of the later, but may not work in this way against all ages and species of pests listed on the label. The products I know of with this MOA do not contain live microbes. This mode of action will reduce insect populations in subsequent generations, not the current one. So use it on a pest with multiple generations per season, or in combination with other MOAs.

 

Things to keep in mind:

If the biopesticide contains live microbes, make sure you…

  • store the biopesticide correctly (and for the correct amount of time); check the label.
  • confirm compatibility of the biopesticide with other products before tank mixing or applying; read the label and contact the manufacturer with questions.

In addition, if the biopesticide contains microbes that need to stay alive for some period of time after application in order to be effective, make sure you also…

  • pay special attention to the recommended optimal environmental conditions for application; start by reading the label.

Remember!

  • Biopesticides are pesticides. Their labels are the law. Read the labels and follow them, along with other pesticide application laws in your state.
  • Not all biopesticides are permitted for use in certified organic production. Check with your certifier if you have questions.

 

Questions to ask when you are considering/purchasing a biopesticide

The manufacturer or dealer should be able to tell you:

  • How does it work (MOA)?
  • Is it alive? Does it need to stay alive to work?
  • Special instructions for storage or use? (e.g., temperature, spray tank pH, time of day)
  • Is it compatible (in the tank, greenhouse, or field) with other products in use (e.g., pesticides, fertilizers)?

 

Additional biopesticide Resources

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program.

Fall is for planting…these resources can help!

A mixture of plant seedlings in plots and trays sitting on a gravel surface
Cooler days and more moisture make fall a less-stressful time for transplanting perennials.

You’ve probably heard that fall is the best time to plant perennials (including seed for perennial wildflowers). Are you planning to start or expand a planting that supports pollinators and natural enemies of pests (beneficial insects) this fall? Trying to decide what to plant? I wanted to make sure you know about some resources from NYSIPM (some of them new this summer) that can help!

Who are you trying to attract?

Red lady beetle with black spots perched on a goldenrod plant
Some lady beetle species weed on pollen, in addition to aphids and other insects.

The good news is that flowers that produce lots of pollen and nectar and provide season-long blooms (usually as part of a mixed planting) will support a diverse group of both natural enemies that eat pests and pollinators. If you want to get a bit more specific than that, you might consider checking out:

  • Natural Enemies and What They Eat in the Field – Targeting a particular pest? This chart can help you determine which natural enemies will help.
  • (New!) Pocket Guide to Beneficial Insects – This guide was created for urban growers in New York City, but fortunately all of the beneficial insects in the Guide can be found throughout NY. It will help you recognize beneficial insects when you see them.

These resources are linked from this page. The NYSIPM website is in the process of migrating, and I’ll update this link once this page moves. You can also read about “friends in the garden” (natural enemies) that you’ll find on the ground and on plants or flying through the air in previous blog posts.

Picking plants

A raised bed containing a variety of different plants (with red, purple, yellow, or pink flowers) and labels naming each plant
Choosing a mixture of flowering plants can provide season-long blooms for beneficial insects.
  • Plants for Natural Enemies (full list) – A very large spreadsheet summarizing data from university research and extension resources; Everything I could find about individual plant species and which insects (especially natural enemies) they support.
  • (New!) Plants for Natural Enemies (2 pg handout) – Much shorter table listing 26 plants (perennials and annuals) that will support natural enemies (and pollinators); Bloom times are for central NY, and may vary in other locations (especially different USDA plant hardiness zones).

These resources are also linked from this page. And I’ve written a few blog posts about choosing plants (here and here).

 

What are you planting this fall?

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program.

Some great biocontrol events coming up!

Next week is full of great biocontrol events! If you are in the Geneva, NY area, don’t miss out!

Thursday August 11 5:30-7:30 PM

wildflowers growing in a field in the foreground, people standing and talking in the background
Participants enjoying last year’s Habitat for Beneficial Insects Open House.

We are in our 5th year of establishing perennial wildflowers and grasses to support pollinators and natural enemies of pests. Perhaps you’ve been following our progress (although admittedly I owe you all an update post or two). Or maybe you keep up with pictures on my Instagram. Now you can see these plots for yourself at our Habitat for Beneficial Insects Open House!

Come visit us any time between 5:30 and 7:30 PM. This outdoor event is free and no registration is required. Just put this address into your GPS:

1097 County Rd. 4
Geneva, NY 14456

Then look for these signs:

New York State IPM logo next to diagrams of a pink echinacea flower and a green Christmas tree

Funds for this project were provided by NYS Dept of Ag and Markets, the Towards Sustainability Foundation, and the USDA National Institute of Food and Ag.

 

Friday August 12, 5-7:30 PM

Researcher points to labeled rows of Christmas trees growing in a field, while meeting attendees watch
Bryan Brown talking about integrated weed management at last year’s event.

As part of a larger Christmas tree IPM project, we’re looking at using biopesticides applied to Christmas tree roots at planting to protect the young trees from root diseases (especially Phytophthora). We’re having a Field Day so that you can see both acres of Christmas trees we’ve planted and learn about early results from the project.

Please do register for this event using the “Field Day” link above!

Like the Habitat for Beneficial Insect Open House, put this address into your GPS:

1097 County Rd. 4
Geneva, NY 14456

Then look for these signs:

New York State IPM logo next to diagrams of a pink echinacea flower and a green Christmas tree

This work is supported by Agriculture and Food Research Initiative – Foundational and Applied Science Grant no. 2021-68008-34179/project accession no. 1025660  from the USDA National Institute of Food and Agriculture.

 

Saturday August 13, 10 AM – 3 PM

raised bed with wildflowers growing in it
This year we planted two new raised beds with perennials that support beneficial insects.

NYS IPM will be at Cornell AgriTech’s 140th Anniversary Open House talking about how to “feed your insect friends”…by creating excellent habitat for them, of course! This spring we planted two raised beds with a mixture of perennials selected to provide pollen and nectar from spring through fall. Come see how these new plantings are growing, learn more about beneficial insects and how to create your own habitat, and pick up some (temporary) tattoos of pest natural enemies! Then visit the rest of the educational displays at Cornell AgriTech.

Funding for our displays at this event is being provided by Cornell AgriTech and NYS Dept of Environmental Conservation.

Which biopesticides work? Updated resources

A caterpillar eats or comes in contact with a bioinsecticide that causes the caterpillar to stop feeding.
Some bioinsecticides cause insect and mite pests to lose their appetites. Depending on the bioinsecticide, it either needs to contact the pest or be eaten by it.

Biological pesticides (biopesticides) are pesticides with active ingredients that are considered natural. According to the EPA they “include naturally occurring substances…microorganisms that control pests…and pesticidal substances produced by plants containing added genetic material.” This last category is more often recognized as certain (but not all) genetically modified organisms (GMOs). The “naturally occurring substances” (plant extracts, some natural chemicals) and microorganisms (bacteria, fungi, viruses) are the focus of today’s post. There’s a deeper dive into how biopesticides work in another blog post.

Biopesticides can be an important tool for integrated pest management because some of them may pose less risk to people or the environment than some conventional chemical pesticides. (But always read and follow the label on biopesticides to ensure you are minimizing risks!)

If you are considering using a biopesticide as part of your IPM program, you will of course want to know whether or not it is effective against a particular pest on a particular crop. A few years ago I wrote a post about efficacy of biocontrol. With some great help, I’ve been collecting summaries of efficacy trials on biopesticides conducted by universities. These summaries are available as downloadable Microsoft Excel spreadsheets for the following crops:

  • Berries
  • Field crops
  • Grapes
  • Greenhouse, nursery, and ornamental crops
  • Hemp
  • Hops
  • Tree fruit

The Cornell Vegetables website has some excellent information about biopesticides for vegetable diseases.

Green leaf with blue rectangles with smiling faces representing microbes as natural enemies of the pest microbes (yellow rectangles with shocked faces). The blue microbes are producing blue droplets (representing antimicrobial compounds).
Microbes used to control pests are biopesticides. In this conceptual diagram, the happy blue microbes are producing antimicrobial compounds that are killing the plant pathogens (represented by yellow rectangles with shocked faces).

Once you download a spreadsheet, take a look at the ‘Notes’ sheet for some important background information, then look at the data on either the ‘Diseases’ or the ‘Arthropods’ (insects and mites) sheet. You can sort the data on either sheet by crop, pest name, name of the product, active ingredient, or other column headings. I’ve included both a simple rating of efficacy (-, +/-, +, ++), and a numerical summary that shows how much each product improved control compared to doing nothing to control the pest.

The spreadsheets do indicate whether each product was registered in New York State at the time the sheet was last reviewed. Remember that you must confirm that the product you want to use is currently registered in New York, and that the label includes your setting, crop, and pest. You can check for current registration and download NYS pesticide labels from NYSPAD.

If you are not able to open an Excel spreadsheet, please let me know and I’m happy to get you the info in a format that works for you.

 

This work is supported by NYS Departments of Environmental Conservation and Agriculture and Markets, as well as the National Institute of Food and Agriculture, Crop Protection and Pest Management Extension Implementation Program, award number 2021-70006-35672.

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program.

Include biocontrol in your 2022 garden plans

Graphic of flowering plants and beneficial insects with the words Biological Control: Partners in the Garden March 15 and 16, 2022
Join us for this virtual conference!

I don’t know about you, but I can’t wait to get some seeds into potting mix and some plans for my garden on paper! While you’re planning your garden, why not join NYS IPM for our virtual conference? This year we’re talking about “Biological Control: Partners in the Garden” and we’ve got a great line up of speakers!

  • Carol Glenister form IPM Labs talks about looking for signs that natural enemies (biocontrol agents) are already at work in your garden
  • John Losey from Cornell University talks about everyone’s favorite biocontrol agent – ladybugs
  • NYS IPM staff will talk about biocontrol for weeds (is there any?), conserving our biocontrol partners in the garden, and more!
  • Mary Centrella from the Cornell Pesticide Safety Education Program will talk about proper use of pesticides to protect garden partners
  • Kyle Wickings will talk about using tiny worms (entomopathogenic nematodes) to deal with lawn grubs

The conference will take place the mornings of Tuesday and Wednesday March 15 and 16, with a special interactive workshop being offered (by yours truly) on Tuesday afternoon (1-3 PM). You’ll receive some pre-workshop materials to help you get the most out of the workshop, and leave with a plan to plant flowers that will feed and support natural enemies in your garden.

The conference is just a little more than a week away, so register soon! Pay what you can afford, and please reach out if the registration fee is a barrier. NYS IPM is committed to making this conference (and all of our resources) accessible.

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program.

EPNs: Good worms

light brown dead grub in a petri dish broken open and surrounded by hundreds of tiny, white, crescent-shaped nematodes
Insect-killing nematodes (tiny white crescent) emerging from a dead insect larva. Photo credit: Peggy Greb, USDA Agricultural Research Service, Bugwood.org

Nematodes are tiny worms. While some of them can damage plants, some prefer to eat insects, and these “good worms” (entomopathogenic nematodes is the technical term, but we can call them EPNs for short) can be helpful biocontrol agents. Teresa Rusinek (Cornell Cooperative Extension eastern NY Commercial Horticulture Program) wrote a guest blog post about her work testing EPNs for control of wireworms in sweet potatoes. Elson Shields (Cornell Entomology) has spent many years perfecting the use of persistent EPNs that are native to New York in agricultural fields where they control insect pests. Kyle Wickings is my go-to expert on using EPNs to manage white grubs in turf. A former graduate student in Kyle’s lab (Max Helmberger) made an amazing video describing the life cycle of EPNs. John Sanderson is the Cornell guru of greenhouse biocontrol (including EPNs for greenhouse insect pests).

So many people have developed so many great materials on EPNs, the purpose of this post is to point you to some of these great resources. Why re-invent the wheel? And if I’ve missed something, please let me know!

John Sanderson (Cornell University) has done some great work evaluating different EPN species for controlling insect pests in greenhouses. You can watch a webinar summarizing this work here.

Carol Glenister (IPM Laboratories) and Elson Shields (Cornell University) did a presentation on “Getting the Most Out of Beneficial Nematodes in Organic Production” for the UMass Amherst Extension Vegetable Program. You can watch the recording on YouTube, and you can read their answers to frequently asked questions online.

Screen shot of Grub ID homepage including the url: grubid.cals.cornell.edu
Proper identification is essential to good IPM, and Kyle Wickings’ Grub ID key helps you do just that.

Need help identifying your white grubs (a critical first step to using EPNs effectively in your lawn)? Kyle Wickings developed a simple key.

Are you concerned about grub damage in your home lawn? Put back that pesticide bottle, and start by scouting and identifying grubs, then apply some EPNs (only if you need them). You can find all the details here.

white grub on soil with a few grass plants nearby
Count how many white grubs you actually have per square foot (and identify them) before deciding if an EPN application would help.

If you are growing alfalfa, Elson Shield’s lab has all the information you need to successfully use EPNs to control alfalfa snout beetles, starting with an overview, and including detailed resources to help you be successful.

Wondering if EPNs can help you control fruit and vegetable insect pests? In consultation with my colleagues, I developed a summary of what we know about which fruit, vegetable, and ornamental pests you are likely to be able to manage with EPNs. More research is ongoing, so this list will continue to evolve.

This work is supported by NYS Departments of Environmental Conservation and Agriculture and Markets.

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program, but was only possible due to the great work done by colleagues. All images are Amara’s, unless otherwise noted.

IPM for establishing Christmas trees: Survival and growth in the first season

Rows of small Christmas trees growing in a field on a sunny afternoon; some are surrounded by wood chip mulch, some by cultivated ground, some by bare ground, and some by tall weeds.
The different weed management strategies we are comparing certainly look different in the field. But how do they impact tree growth and quality?

Back in June we introduced you to a new project comparing different methods for weed and root disease management when establishing Christmas tree seedlings. Recall that this is a collaboration among Bryan Brown, Amara Dunn, Brian Eshenaur, Betsy Lamb, and Lynn Sosnoskie. We wrapped up our first season in October, and we have a first look at some of the data. In this post, we’ll focus on tree survival and tree growth. There’s a lot more weed data!

Treatments

Let’s start with a quick reminder of the treatments we were comparing. Each row of 28 trees received the same weed management treatment. Each row was also divided into four plots of seven trees each. Each plot within a row received a different root treatment. Here’s a map of how the treatments were laid out in the field.

Weed management (in-row, within a 30” band around the row of trees; between row zones were seeded with grass and mowed 4 times) :

  • Cultivate – three times early in the season using a tractor drawn KULT Kress Argus Toolbar with sweeps, finger weeders, and a rear side-shift adjustment
  • Herbicide – conventional active ingredients (oxyfluorfen and pendimethalin applied shortly after planting, with a fall application of glyphosate) as a control treatment
  • Mow – mow about every two weeks with a walk-behind mower
  • Mulch – 3 inches of chipped shrub willow mulch
  • Untreated – No weed management at all

Root disease management:

  • ProPhyt (active ingredient: potassium phosphite) – a biopesticide applied by dipping bare roots of seedlings just before planting; mixed 1.28 fl oz in 2 gallons of water for 140 trees (11 fl oz/A if you plant 1,200 trees/A)
  • RootShield PLUS WP (active ingredient: Trichoderma harzianum Rifai strain T-22 and Trichoderma virens strain G-41) – a biopesticide applied twice (the day after planting and 7 weeks later) as a drench around each tree (24 oz/A in 171 gallons of water/A)
  • Subdue Maxx – a conventional fungicide applied twice (the day after planting and 5 months later) as a soil-directed spray (2.5 pt/A in 140 gal/A in a 6-inch band on either side of the row of trees). We made the application with a hand-pump backpack sprayer fitted with a TeeJet TTI11005 nozzle with a shield rotated parallel to the row of trees. The maximum pressure possible with this sprayer is 60 psi. After application, we applied an extra 0.45 gallon of water per plot of 7 trees with the same sprayer (280 gal/A additional water).
  • Water – 1 pt of water poured around each tree at planting, as a control.

What we measured

We’re interested in how the weed and root disease treatments impact survival, growth, and quality of these trees. Thanks to our excellent technicians, Marcus and Erik, for helping us measure all of these trees! Betsy and Amara were helping, too, but in this picture Amara is behind the camera.

A woman in a pink shirt comparing a small Christmas tree to a piece of paper, while a man in a plaid shirt measures the height of a small Christmas tree seedling; both are in a newly planted field with freshly tilled soil
Betsy and Marcus measuring trees and evaluating needle color in May.

On May 25 (about a week after planting) and again on October 6 we measured the height of each tree (from the soil to the tallest part of the tree, even if it wasn’t the leader anymore) and the diameter of the tree trunk 4 inches above the soil. In both May and October, we also rated the color of the needles using this scale. However, we only used: 2 (darkest green), 5 (medium green), 7 (paler green), and 9 (yellow or brown).

Of course, measuring and rating each tree also allowed us to take note of which trees had died (versus a few that unfortunately succumbed to “mower blight”).

What we found

Bar graph showing that trees generally survived better when treated with ProPhyt, except not if weeds were managed with herbicide. The impact of root treatment varied, depending on which weed management strategy was used.
Percentage of trees in each plot (out of seven trees total) that were still alive by October 2021, not counting a couple that were accidentally mowed. Each bar is the average of four plots for each combination of root treatment (color of bars) and weed management strategy (along x-axis). The lines on each bar show variability (one standard error above and below the mean value).

It’s too early to know for sure, but it’s possible that the root treatment that results in the best seedling survival might depend on which weed management strategy you use. For example, after just one year, the RootShield PLUS-treated trees did better than the ProPhyt-treated trees where herbicide was used, but not where the weeds were allowed to grow unchecked (‘Untreated’). We haven’t done a statistical analysis on the data, yet, but the little lines at the top of each bar are an indication of the amount of variability amongst the four plots in each treatment (one standard error above and below the mean percent survival, for those who might be interested).

Bar graph showing that trees might have grown slightly more when weeds were managed with herbicides. The impact of root treatment varied, depending on which weed management strategy was used.
Change in height of Christmas trees from May to October 2021. Each bar is the average of up to 28 trees (7 trees in each of 4 plots) for each combination of root treatment (color of bars) and weed management strategy (along x-axis). The lines on each bar show variability (one standard error above and below the mean value).

These Fraser fir seedlings grew between 1 and 2.5 inches during their first season. Much like the tree survival, the root treatment that produced the most growth wasn’t consistent across all weed management strategies. Results for tree trunk diameter were similar.

Bar graph showing that needle color might be slightly darker in the plots that were treated with herbicide or no weed management. The impact of root treatment varied, depending on which weed management strategy was used.
Average needle color when trees were rated in October. Lower numbers indicate darker green color. Each bar is the median value of up to 28 trees (7 trees in each of 4 plots) for each combination of root treatment (color of bars) and weed management strategy (along x-axis).

Recall that needle color was rated as 2 (darkest green), 5, 7, or 9 (most yellow or brown). So on this graph, shorter bars indicate better needle color. Also, this rating scale impacted how we summarized the data. Instead of taking the mean needle rating, we used the median. (Here’s a quick refresher on the difference.) And the graph doesn’t have those little lines to summarize the variability in each treatment. Too early to draw firm conclusions, but again, there might be some interactions between root treatment and weed management strategy.

What does it cost?

Economic risk is one of the risks we seek to reduce through IPM, so we’ve been keeping track of the costs associated with our pest management strategies. Based on the way we applied the root treatments and some local price estimates, here’s what we would have spent per acre for these treatments, assuming we planted 1,200 trees on each acre (that’s 6 ft x 6 ft spacing).

 

Fungicide Rate/A Number of applications Cost/A (Supplies) Cost/A (Labor1)
ProPhyt 11 fl oz2 1 $4 $1,037
RootShield PLUS WP 24 oz3 2 $123 $4,150
Subdue Maxx 2.5 pt3 2 $82 $2,074
Water 1 $0 $2,075

1We assumed a labor rate of $20/hr. These costs were calculated based on the time it took us to apply the products. This includes drenching each tree by hand (RootShield PLUS WP and water) and applying Subdue Maxx (and additional water to move it into the soil) with a backpack sprayer. On a larger scale, there’s surely a more efficient way to do this.

2Seedling roots were dipped in a ProPhyt solution prior to planting. The rate on the label is 4 pt/100 gallons of water. We mixed up 2 gallons of root dip solution (containing 1.28 fl oz of ProPhyt) to treat 140 trees. If we had used a fresh 2 gallons for every set of 140 trees, we would have used 11 fl oz of ProPhyt on an acre of 1,200 trees.

3Because RootShield PLUS WP was applied as a drench to each tree and Subdue Maxx was applied as a soil-directed spray banded on either side of the row, these rates are per acre of ground to which pesticide was applied. This is less than the total space taken up by these trees in the field. Read and follow the pesticide label for instructions on calculating quantity of product needed for banded applications.

And here’s a summary of our weed management costs. You can see all the details of these costs (including labor and supplies) here.

In-row weed management Cost/A (labor and supplies)
Cultivate $248
Herbicide $86
Mulch $1,153*
Mow $293
Untreated $0

*Assumes woodchips can be obtained locally at no cost

Take home

With only one season of data, it’s too early to draw conclusions about the effectiveness (or cost effectiveness) of each treatment. So far, survival of trees treated with ProPhyt is looking very good across most weed management strategies. And we’re seeing some indication that the best (in terms of tree survival, growth, or color) root treatment to use may vary depending on what you’re doing to manage weeds.

In late October we also dug up five dead trees and sent them to the Cornell Diagnostic lab to check for Phytophthora. The trees had been dead for a while, so they were only able to test for the presence of any Phytophthora species (which could include some that don’t cause disease on Christmas trees). Four out of five trees came back positive, which makes us feel more confident that we picked a good field for this trial…if by “good” you mean one where trees will be exposed to Phytophthora. For the purposes of this project, that’s exactly what we mean.

Please let us know if you have questions and stay tuned for more updates on this project. We’ve got at least two more years to go! You can check back on this blog (subscribe so you’ll know when new posts are available!), follow Lynn Sosnoskie and Amara Dunn on Twitter or on Instagram (@specialtycropweedscience and @biocontrol.nysipm), or check out Bryan Brown’s webpage. We’ll also be hosting another field event in 2022 and hope to provide updates at future Christmas Tree Farmers Association of NY meetings.

USDA logo, accompanied by the words: National Institute of Food and Agriculture, U.S. Department of Agriculture

This work is supported by Agriculture and Food Research Initiative – Foundational and Applied Science Grant no. 2021-68008-34179/project accession no. 1025660  from the USDA National Institute of Food and Agriculture.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program, with helpful input from project collaborators. All images are hers, unless otherwise noted.