Neonic Alternatives for Vegetables

Comprehensive field trials conducted in Western and Central New York during the spring and summer of 2022 evaluated alternatives to the use of neonicotinoids or chlorpyrifos for managing insect pests in cabbage, potatoes, onions, snap beans, sweet corn and squash. Commodity-specific research focused on treatments for controlling cabbage maggot (Delia radicum), Colorado potato beetle (Leptinotarsa decemlineata) and seedcorn maggot (Delia platura).

Progress Reports

Cabbage

This experiment evaluated insecticides to manage cabbage maggot (Delia radicum) in cabbage. The trial was conducted near Albion in a commercial cabbage field during the spring of 2022. Fourteen treatments and an untreated control were arranged in a RCBD and each treatment was replicated four times. Eight treatments included Verimark (cyantraniliprole-IRAC 28) applied at varying rates and via either as a transplant tray drench, transplant water or treatment or directed spray to the crop after transplanting. Three treatments included Mustang Maxx (zeta-cypermethrin-IRAC 3A) applied as a directed spray to the crop at varying frequencies after planting, and Coragen (chlorantraniliprole-IRAC 28) as a transplant water treatment with or without a Mustang Maxx directed spray. On June 10, 2022, the percentage of cabbage plants infested with cabbage maggot in each plot was recorded. Results indicated that Verimark, applied either as a tray drench treatment alone, or in combination with a directed spray two weeks after transplanting, provided near perfect protection of the crop from cabbage maggot. Applications of Mustang Maxx and Coragen failed to control the pest.

Potatoes

This experiment evaluated insecticides to manage Colorado potato beetle (CPB) (Leptinotarsa decemlineata), in potatoes. The trial was conducted near North Rose, New York on a private research farm in the spring and summer of 2022. Five treatments and an untreated control were arranged in a RCBD and each treatment was replicated five times. Three treatments included Platinum (thiamethoxam – IRAC 4A) applied in furrow at planting to manage first-generation CPBs followed by foliar applications of either Vantacor (chlorantraniliprole –IRAC 28), Calantha (ledprona –RNAi) or Radiant SC (spinetoram – IRAC 5) for second-generation CPBs. The other treatments included either Vantacor (chlorantraniliprole –IRAC 28) or Calantha (ledprona –RNAi) applied as foliar sprays to manage first-generation CPBs and the reciprocal was used for second generation CPB control. CPB life stages and levels of defoliation were recorded weekly in plots during June, July and August. Results indicated that all Platinum treatments provided the best protection of the potato crop against first-generation CPBs, while Vanatacor and Radiant provided the best protection of the potato crop against the second-generation of CPBs.

Onions

Several experiments evaluated insecticides delivered as seed treatments to manage onion maggot (OM), (Delia antiqua), in onion. Trials were conducted near Owego, New York on commercial farms in the spring of 2022. New seed treatment products included PLINAZOLIN Technology (isocycloseram – IRAC 30), Lumiderm (cyantraniliprole – IRAC 28) and Lumiverd (spinosad – IRAC 5). Trigard (cyromazine – IRAC 17) seed treatment was included as a standard. Additionally, Exirel (cyantraniliprole – IRAC 28), Radiant SC (spinetoram – IRAC 5) and Mustang Maxx (zeta-cypermethrin - IRAC 3A) were evaluated as directed sprays over the top of onion seedlings when OM flies were active. Treatments were arranged in a RCBD and treatments were replicated five times. Numbers of onion plants dying from onion maggot infestation in each plot were recorded once or twice per week until the end of the first generation in early July. Results indicated that the highest rate of PLINAZOLIN technology and the highest rate of Lumiverd provided excellent protection of the onion crop from OM damage, and control was similar to that provided by Trigard. Lumiderm did not provide OM control, nor did any of the directed spray treatments.

Snap Beans

The experiment evaluated insecticides delivered as seed treatments to manage seedcorn maggot (SCM), (Delia platura), in snap beans. The field trial was conducted at the Fruit and Vegetable Farm in Geneva, New York in the spring of 2022. Six treatments plus an untreated control were arranged in a RCBD with each treatment replicated 6 times. Treatments included PLINAZOLIN Technology (isocycloseram – IRAC 30), Lumivia (chlorantraniliprole – IRAC 28), Fortenza (cyantraniliprole – IRAC 28) and Entrust (spinosad – IRAC 5). Cruiser 5FS (thiamethoxam – IRAC 4A) seed treatment was included as a standard. Seedlings damaged by SCM larvae often have a “snake head”-like appearance after they emerge, which is caused by maggot feeding on the cotyledon before plant emergence (Fig. 4B). Healthy plants are shown in Fig. 4A. The number of healthy plus SCM-damaged plants was visually recorded on June 8, which was 15 days after planting. Some seeds germinated but failed to emerge because they were attacked very early by SCM larvae. This type of damage was not captured when assessing emerged plants as described above. Therefore, we also inspected 25 plants and germinated seeds within the entire plot for the presence of maggots and their damage. Based on the SCM damage assessment of above and below-ground portions of plants or germinating seeds, results indicated that all insecticide treatments performed equivalently well. However, when only above-ground portions of plants were assessed, Fortenza was significantly better than Lumivia, but did not differ from the other insecticide treatments. No differences in SCM damage were evident between the two rates of PLINAZOLIN® Technology.

Sweet Corn and Squash

These experiments also evaluated insecticides delivered as seed treatments to manage seedcorn maggot (SCM) (Delia platura) in sweet corn and squash. The field trials were conducted at the Fruit and Vegetable Farm in Geneva, New York in the spring of 2022. Six treatments plus an untreated control were arranged in a RCBD with each treatment replicated six times. Treatments included PLINAZOLIN technology (isocycloseram – IRAC 30), Lumivia (chlorantraniliprole – IRAC 28), Fortenza (cyantraniliprole – IRAC 28) and Entrust (spinosad – IRAC 5). Cruiser 5FS (thiamethoxam – IRAC 4A) seed treatment was included as a standard. Damage was assessed by recording plant stand and taking a subsample of seedlings to inspect for maggots and their damage. Unfortunately, SCM pressure was too low and we were not able to obtain sufficient data to evaluate the performance of the treatments.