By Heidi Lindberg and Jeremy Jubenville et.al
Michigan State University Extension has updated their insect and disease management recommendations for the 2022 greenhouse season. There only have been a few minor changes from the previous 2021 recommendations. These recommendations are updated yearly to reflect efficacy of pesticides as MSU Extension specialists and their nationwide colleagues perform research trials evaluating the products against common greenhouse insects, mites or diseases. The pesticides are evaluated by a network of researchers involved in the IR-4 Project, a research group that facilitates the labeling of pesticides on specialty crops, including greenhouse crops.
Insect management
MSU Extension entomology specialist for ornamentals, David Smitley has released his “2022 Greenhouse Pest Management with Insecticides” recommendations. These are the recommended products to control thrips, aphids, whiteflies, spider mites, broad and cyclamen mites, fungus gnats, mealybugs and Florida fern caterpillar.
Growers of greenhouse vegetables and greens can use the guide, “Recommended Insecticides for Common Greenhouse Pests on Vegetables, Herbs and Leafy Greens,” when considering an insecticide application. The guide provides the names of the products, active ingredients, vegetable crops on the label and recommended pests they control. For more information on the guide, see the MSU Extension article, "Insecticides for common pests on greenhouse vegetables and transplants."
Download 2022 Greenhouse Pest Management with Insecticides Recommendations
Notes on insecticides for 2022
There have been a few new products registered and released within the last three years:
- Novato (clofentazine) has been added for spider mite control. This is the same active ingredient that was in Apollo. It works very well if resistance is not a problem. Because it is not used in the greenhouse industry much anymore, resistance may not be as much of a problem as it was in the past, and it is certainly worth trying.
- Ventigra (afidopyropen) is now labeled for control of aphids, whiteflies and mealybugs. Plants sensitive to Ventigra include coleus, poinsettia (in bract), impatiens and petunias (in flower).
- Sarisa (cyclaniliprole) is now labeled for control of thrips, whiteflies and mealybugs. In recent research tests at Michigan State University we found Sarisa to reduce the number of thrips on marigolds as well as the most recent industry standard for thrips control, Pylon.
- Pradia (cyclaniliprole and flonicamid) is a combination product, so it is like using Sarisa and Aria together. In research tests at MSU, Pradia also reduced the number of thrips on marigolds as well as Pylon, but it appeared to last a week or two longer than Sarisa. More testing of both products is needed.
In recent trials at Michigan State University, we found Sarisa and Pradia reduced the number of thrips on marigolds as well as the most recent industry standard for thrips control, Pylon. Thrips control from Pradia appeared to last a week or two longer than that for Sarisa. Pradia (cyclaniliprole and flonicamid) is a combination product, so it is like using Sarisa and Aria together. More testing of both products is needed.
For summaries of research evaluations of insecticides used for thrips on ornamentals, go to the IR4 Ornamental Horticulture website:
Disease management
MSU Extension plant pathologist Mary Hausbeck has released her new "2022 Greenhouse Disease Management" recommendations. The products are classified on a range from “A+” or “B/B-” team products. The “A” team products provide the best control for the diseases, and “B” team products are those that provide limited control and are good to include in a spray rotation.
Hausbeck has also provided an updated “2022 Greenhouse Impatiens Downy Mildew Program” for both susceptible and impatiens downy mildew-resistant cultivars.
Hausbeck and her colleagues have also developed a guide for disease management specifically for vegetable and herb crops. The guide provides the following information about each registered product for vegetable transplants and herbs: 1) active ingredient, 2) trade name of the product, 3) FRAC code (a guide for alternating products to delay/reduce pathogen resistance) and 4) re-entry interval. The disease recommendations are grouped by crop groups: 1) brassica, 2) cucurbit, 3) leafy, 4) fruiting and 5) herbs. Within each crop grouping, the table includes the target pathogen including: bacterial blight, downy mildew, leaf spot, powdery mildew, Phytophthora, Rhizoctonia and Sclerotinia.
Download 2022 Greenhouse Disease Management Recommendations
Changes from 2021
The disease management recommendations are very similar between 2021 and 2022.
For the 2022 growing season, the recommendations for Thielaviopsis include only the “A” team – or very effective products – due to the seriousness of the pathogen. The two “A” team fungicides for Thielaviopsis are the high labeled rates of 3336/OHP 6672 and Terraguard SC.
While most fungicides classified as the “A” Team for Botrytis are the same as last year, Pageant Intrinsic has been moved to the “B” team (only recommended under low disease pressure). Due to increased fungicide resistance frequencies, the following products were removed from the “B” team and are no longer recommended for Botrytis control: Heritage, Compass, and Insignia.
Metconazole (Tourney) has been dropped entirely from the recommendations because the label states that the product is for outdoor use on ornamentals but does not mention greenhouse applications. In recent trials, that fungicide also had significant PGR effects on some plant species.
Source : msu.edu