Tag Archives: pesticide

agriculture

Biopesticides for tomato bacterial diseases: On-farm demos

row of tomato plants with some green fruit and a sign that says Double Nickel 1 qt/A alt. Kocide
On-farm demonstration of reducing copper applications by alternating with biopesticides to protect against tomato bacterial diseases.

Last summer I wrote about integrated pest management strategies (IPM) for tomato bacterial diseases and how biopesticides fit into strategies for managing these diseases. You’ll recall that research trials conducted at Cornell in Chris Smart’s lab indicated that you could replace some copper sprays with the biopesticides Double Nickel or LifeGard and achieve the same level of control of tomato bacterial diseases. In 2023, we wanted to demonstrate what this might look like on vegetable farms around New York State – Long Island, eastern NY, and western NY. Here’s what we observed.

 

Results from On-Farm Demos

Biopesticides are not a panacea for tomato bacterial disease problems. When disease pressure is severe and weather is favorable, bacterial diseases can be difficult to manage, even with copper-based fungicides. Canker is especially difficult to manage because the bacteria that cause the disease move systemically within the plant. Successful management of bacterial diseases in tomatoes requires the use of multiple IPM tools, including starting with clean seed and healthy transplants, and using new (or effectively disinfected) tomato stakes.

On farms that experienced tomato bacterial disease outbreaks, adding Double Nickel did not satisfactorily control bacterial disease. These farms had very uneven distribution of tomato bacterial canker across the fields, complicating comparisons between the Double Nickel alt. copper treatments and the copper only treatments. Two farms (in western NY) saw slight to moderate increases in fruit quality when they added Double Nickel sprays in between copper applications compared to applying copper every 10-14 days. This resulted in estimated 2% and 37% increases in fruit value, corresponding to an extra $19 (from nine harvests) or $72 (from four harvests) from 100 row feet of tomatoes. However, the Double Nickel sprays were in addition to copper sprays, not replacing them. We don’t know if applying copper every 7-10 days would have resulted in better disease control. On the third farm, we saw no benefit of replacing half of the copper applications with Double Nickel.

The two cooperating Long Island farms saw no bacterial disease in 2023. But replacing half of the copper applications with either Double Nickel or LifeGard still seemed to have economic advantages. We estimate that the value of their crops increased by 7% and 59%, or $244 and $1,617 per 100 row feet of tomatoes harvested four times. Note that the price for fresh tomatoes on Long Island is high compared to some other markets in NY. We used $5-$6/lb in our Long Island estimates. Also, we don’t know what would have happened if there had been a bacterial disease outbreak on these farms.

On all cooperating farms, we collected data on very small sections of the field (10-40 row feet of tomatoes). Estimated potential impacts on yield over much larger areas should be taken with a grain of salt.

Green Roma tomato fruit with both white spray residue and classic fruit symptoms of tomato bacterial canker – brown spots with a white ring around them
Tomato bacterial canker is a difficult disease to manage, even with weekly copper applications. Use of multiple integrated pest management (IPM) tools yields the best results. Photo credit: Crystal Stewart-Courtens.

 

Economics

We researched some prices for pesticides from a few different suppliers. Below are the assumptions we made to calculate some price estimates and make comparisons among some biopesticides and copper pesticides. Prices for pesticides can vary across regions and time. If you think any of these numbers are far out of line, please let Amara know!

If you are applying… and a container costs you… and you apply at a rate of… Your cost per A per application is:
Actinovate AG $115/18 oz bag 7.5 oz/A (range on label is 3-12 oz) $48.00
Double Nickel LC $85.25/1 gal 1 qt/A (recommended for tomato bacterial diseases) $21.31
LifeGard WG $148/1 lb bag 4.5 oz/100 gal and 50 gal/A = 2.25 oz/A $20.80
copper (Kocide 3000-O or Badge X2) $102/10 lb bag 1.25 lb Kocide, 1.8 lb Badge X2 (highest rate on label) $15.00
copper (Badge SC) $150/2.5 gal 1.8 pt/A (highest rate on label) $13.58
Copper (Champ Formula 2 Flowable) $139.95/2.5 gal 1.33 pt/A $9.31
copper (Cueva) $114/2.5 gal 1 gal/A (label rate is 0.5-2 gal) $46.27

As you can see, the biopesticides in the table range from fairly similar in price (Double Nickel and LifeGard) to approximately 5 times the cost of the less expensive coppers (Actinovate). Each copper application replaced with either Double Nickel or LifeGard is estimated to increase the pesticide cost by $6-$12 per acre per application. If a grower makes eight applications in a season to protect tomatoes from bacterial diseases, this would be an increase of $24-$48 per acre for the season if half of the copper applications are replaced with Double Nickel or LifeGard. If a grower adds LifeGard or Double Nickel applications to a 14-day copper spray program, the cost increase is greater. Purchasing product for four additional applications costs an extra $84 per acre, not including other costs of making more applications, like fuel, labor, equipment depreciation, etc.

 

Protecting people and the environment

Replacing some copper sprays with biopesticides can have other benefits. For example, the following table compares restricted entry intervals (REIs), label signal words, and field use ecological Environmental Impact Quotient (EIQ) for several biopesticides and copper formulations. Shorter REIs indicate a pesticide has lower toxicity to agricultural workers. The signal word shows the relative acute toxicity of the pesticide to the pesticide applicator.

 

Product Active Ingredient (%) Rate REI Signal word Field Use Ecological EIQ1
Actinovate AG Streptomyces lydicus WYEC 108 (0.037%) 12 oz/A 4 hrs Caution NA
Double Nickel LC Bacillus amyloliquefaciens strain D747 (98.85%) 1 qt/A 4 hrs none on label NA
LifeGard WG Bacillus mycoides isolate J (40%) 4.5 oz/A 4 hrs Caution NA
Serenade Opti2 Bacillus subtilis QST 713 (26.2%) 20 oz/A 4 hrs Caution 7.2
Badge SC copper hydroxide (15.36%); copper oxychloride (16.81%)3 1.8 pt/A 48 hrs Caution 40.1
Champ Formula 2 Flowable copper hydroxide (37.5%) 1.33 pt/A 48 hrs Warning 34.5
Cueva copper octanoate (10%) 2 gal/A 4 hrs Caution NA
Kocide 3000-O copper hydroxide (46.1%) 1.25 lb/A 48 hrs Caution 38.2
MasterCop copper sulfate pentahydrate (21.46%) 2 pt/A 48 hrs Danger 66.4

1 The Environmental Impact Quotient (EIQ) seeks to quantify the environmental impacts of pesticides. Higher numbers indicate more negative impacts. The values reported here are “field use” values, calculated based on the rates listed in the table. These values vary depending on how much product you use per acre. The ecological component summarizes risk to fish, birds, bees, and beneficial insects.

2 The active ingredient in Serenade Opti is in the EIQ database, while the active ingredients of the other biopesticides in this table are not. The EIQ for Serenade Opti is expected to be similar to those of Double Nickel and LifeGard because they have similar active ingredients. It may also be similar to the EIQ for Actinovate.

3 Only copper hydroxide – not copper oxychloride – was in the EIQ database, so this ecological EIQ was calculated using 32.17% copper hydroxide (sum of the percentages of the two active ingredients).

 

Other benefits of reducing copper applications on a farm could include:

  • It reduces the risk of selecting for tomato bacterial pathogens that are resistant to copper.
  • Many copper fungicides leave a visible residue on fruit, which may impact marketability if applied close to harvest.

 

Update on labels

In last summer’s post we noted that neither Double Nickel nor LifeGard included tomato bacterial canker on their labels. In New York State, formulations of these biopesticides now have 2(ee) labels that include this disease on tomatoes. Make sure you have a copy of both the original label and the 2(ee) label in your possession if you are using these products for tomato bacterial canker in NY. If you are in NY, you can find these and other labels through NYSPAD.

 

The Bottom Line

  • It is very important to use all your IPM tools for tomato bacterial disease management, especially for canker. If you are bringing canker to your field in seedlings or on tomato stakes, it will be very difficult to catch up with the disease using any pesticide if weather conditions favor disease.
  • Some biopesticides are competitively priced (per bottle and per acre) with copper formulations. Replacing a few copper applications with these products will not cost you much more.
  • Replacing some copper applications with biopesticides offers some additional benefits, including copper resistance management, and potentially reduced risk to the environment and human health.

 

 

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-Silver, Biocontrol Specialist with the NYSIPM program. Thanks to collaborators Chris Smart, Professor in the School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section at Cornell University, Crystal Stewart-Courtens, Extension Vegetable Specialist, Eastern NY Commercial Horticulture Program; Elizabeth Buck, Cornell Vegetable Program; Margaret McGrath, Retired Faculty, School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section at Cornell University, and Sandra Menasha, Cornell Cooperative Extension, Suffolk County. Support for this project was provided by the NY Farm Viability Institute.

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Uncategorised

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.

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agriculture

Protect Pollinators and Natural Enemies of Pests, Choose Pesticides Carefully

A bumble bee and a smaller bee resting on a magenta cosmos covered with tiny water droplets
These bees are just two of the beneficial insects you’ll want to protect from pesticides.

Hopefully we can all agree that protecting friendly insects (pollinators and natural enemies of pests) on our farms and in our gardens and landscapes is important. We want to manage pests, without hurting bees, butterflies, ladybugs, parasitoid wasps, minute pirate bugs, hover flies, ground beetles, and so many more of our insect friends. Using IPM tools other than pesticides is a great way to do this. When it is necessary to use pesticides as an IPM tool, how do you choose a pesticide – whether it is organic, conventional, or biological – that poses the least risk?

Practices that help reduce risk to beneficial insects

No matter how hazardous or toxic any substance is, insects are only at risk if they are exposed to that substance. By using integrated pest management practices like crop rotation, sanitation, and scouting for pests, you can reduce the number of pesticide applications needed to manage pests. Making fewer pesticide applications is a great way to start protecting beneficial insects. Some pesticides are particularly dangerous to insects because they linger so long in the environment after they are applied (have a long residual), posing a greater risk. Other pesticides quickly break down in the environment after being applied to plants, so they pose less risk.

Bee pollinating a cucurbit flower
Wild bees are important pollinators of cucurbit flowers. We can thank them for many of our pumpkins, squashes, cucumbers, and melons.

Being careful about when you apply a pesticide can also reduce the likelihood that a beneficial insect will be exposed to it. Bees are less active at certain times of day (especially early morning and evening). However, some wild bee species forage at different times of day. For example, squash bees are early risers, and can be found visiting squash, pumpkin, and cucumber flowers before honey or bumble bees are active. Check the area where you plan to apply a pesticide, and pick a different time if bees are present. Some pesticide labels require that you do not apply that product while bees are foraging. Some pesticides will still harm bees that visit a flower some time after the pesticide is applied. Avoiding pesticide applications when plants are flowering will provide additional protection to beneficial insects, but may not be practical on all crops.

Where you apply pesticides also matters. Have you planted some habitat for beneficial insects? Prevent pesticide spray drift into these habitats. Are there flowers blooming amongst the grass on the orchard floor? Mowing them before you spray the fruit trees overhead could make insects less likely to visit during or right after you spray.

Resources to consult

First, read the pesticide label (and follow it). The label is the law and will have instructions on how to protect pollinators and other non-target organisms when using a pesticide.

If you know the pesticides you are considering, and especially if you know the specific natural enemies you are trying to protect, you can find some good information from companies that sell beneficial insects, or pesticides. I am aware of searchable databases or charts describing pesticide compatibility from four companies that sell (mostly) arthropod and nematode natural enemies: Agrobio, Biobest, BioWorks, and Koppert.

EIQ stands for Environmental Impact Quotient. You can read more details on the NYSIPM website, but in a nutshell the EIQ quantifies the risks of pesticides. You can use the EIQ calculator on our website to compare these numbers for different pesticides at the rates you plan to use them. The higher the number, the higher the risk. There are different components to the EIQ; risks to consumers, workers, and the environment (ecological). The ecological risk includes risks to natural enemies (as well as fish, birds, and bees). The EIQ calculator will give you an overall EIQ value as well as values for each category of risk (consumers, workers, ecological). Or, you can download this spreadsheet of EIQ values for pesticides, and sort by values for bees or beneficials (columns P and Q).

The University of California IPM Program’s pesticide active ingredients database summarizes the toxicity of some pesticides (including insecticides) to natural enemies and pollinators, as well as other hazards.

The Cornell Pollinator Network produces Pollinator Protection Guides for an increasing number of crop groups to help you understand the toxicity of different pesticide active ingredients to bees.

orange and black-striped fly with large eyes perches on small white flowers
Larvae (maggots) of this hover fly are excellent aphid predators. Killing your hover flies with pesticides could contribute to an aphid outbreak.

A few pesticides to avoid

You’re using good IPM, and you still need to use an insecticide. You’re trying to choose. I used information I collected from a few different sources (listed at the end of this post) to categorize some insecticides as “most” or “moderately” harmful. These are not exhaustive lists.

Most harmful to beneficial insects:

  • Carbaryl – active ingredient found in some products called Sevin
  • Neonicotinoids – active ingredients include imidacloprid, acetamiprid, thiamethoxam and may be found in such products as Admire, Assail, and Actara; In NY many products with these active ingredients are now classified as restricted use, so only certified pesticide applicators are allowed to buy or use them.
  • Natural pyrethrins – PyGanic is one product with this active ingredient; similar to synthetic pyrethroids, but this active ingredient degrades quickly in the environment (short residual)
  • Synthetic pyrethroids – active ingredients include bifenthrin, cypermethrin, lambda-cyhalothrin, permethrin, and others; can be found in products called Sevin, Eight, Warrior, and others; similar to natural pyrethrins, but last much longer in the environment (long residual)
  • Spinetoram – Radiant is one product that contains this active ingredient; a synthetic version of spinosad, but more toxic to beneficial insects than spinosad

Moderately harmful to beneficial insects:

  • Azadirachtin – active ingredient found in products such as Aza-Direct, Azaguard, Neemix
  • Bifenazate – active ingredient found in products such as Acramite
  • Chlorantraniliprole – active ingredient found in Coragen; among natural enemies, parasitoid wasps are probably most at risk. There may be some synergistic effects on bees when combined with other pesticides (see Cornell Pollinator Protection Guides)
  • Indoxacarb – active ingredient found in products such as Avaunt
  • Insecticidal soaps – active ingredient is potassium salts of fatty acids and can be found in M-Pede and many other products; most harmful to soft-bodied insects (including predatory mites), while beetles may be less susceptible
  • Spinosad – active ingredient in Entrust; similar to spinetoram, but it is the natural version of this chemical; not as toxic to beneficial insects as spinetoram

So what are the alternatives?

Remember that pesticides, by definition, are toxic to some living things; that’s why they kill and repel pests. There is no such thing as a completely safe pesticide. But here are a few insecticides that are gentlest on beneficial insects. And let me reiterate: Reducing the use of pesticides through good IPM is the best way to protect insects from pesticides.

  • Beauveria bassiana – several strains of this fungus are active ingredients in different insecticides, including BotaniGard
  • Bt or Bacillus thuringiensis – bacterial active ingredient in pesticides such as Agree, Dipel, and others; quite specific to the insect groups specified on the label; different subspecies are effective against different groups of insects
  • Flonicamid – active ingredient in Beleaf
  • Horticultural oils – there are many different active ingredients that fall in this group; may be more toxic to bees than to natural enemies, but require direct contact with the insect
  • Cordyceps (formerly Isaria or Paecilomyces) fumosorosea – another fungal active ingredient found in products such as PFR-97
  • Clarified hydrophobic neem oil – Note that “whole” neem oil contains azadirachtin (which I listed in the “moderately harmful group”), while clarified hydrophobic neem oil does not. Azadirachtin is extracted from neem oil, leaving the clarified hydrophobic neem oil behind.
Small insect with a black and white diamond pattern on its back on a sunflower petal
This cute little insect is a minute pirate bug. In addition to munching on pollen, it will also eat small pests like thrips, mites, and small caterpillars.

A few reminders…

  • Remember that the information in this post is not a substitute for a pesticide label. The label is the law, and you must read and follow the label of any pesticide you are using. Laws and labels change. It is your responsibility to use pesticides legally. Trade or company names used here are for convenience and information only; no endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.
  • For questions about pesticide use, regulations, and safety, contact the Cornell Cooperative Extension Pesticide Safety Education Program. If you live in New York State, you can find labels for pesticides that are registered in NY at the DEC’s NYSPAD website.
  • Just because a pesticide isn’t on the “most” or “moderately” harmful lists above, does not mean it is harmless to insects. These lists are not exhaustive, and for some products insufficient information exists.

  Sources consulted:

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. Special thanks to Diana Obregon Corredor for providing review and input.

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