New products boost citrus psyllid resistance management options

02/18/2013 04:48:00 PM
Renee Stern

The company anticipates gaining EPA approval by late April or early May for a foliar application, to be marketed as Exirel, and a soil drench application, to be marketed as Verimark.

Florida registration likely will follow shortly after, Mares says.

Verimark is aimed at "a very focused market" to protect trees less than 4 feet tall, he says. Currently, only neonicotinoids are approved as soil applications for psyllid control on young trees.

Adding another weapon at this growth stage is particularly useful for resistance management, says Henry Yonce, president of KAC Agricultural Research in Deland, Fla.

Yonce, who participated in field trials, says the soil drench also provides "excellent" leafminer control. Depending on tree size and application rates, cyazypyr's effect on leafminers can stretch to 100 days.

Once past that growth stage, growers need to focus on protecting developing trees and leaf flush with foliar sprays, Mares says.

Timing Exirel applications early in the spring growth cycle will help protect leaf flush from both Asian citrus psyllids and leafminers. Mares also sees potential during summer flush.

Year-over-year field trials show that a strong start at spring leaf flush pays off at the end of the season in higher yields, he says.

Cyazypyr has little impact on predators and other beneficial insects, reducing the risk of secondary pest outbreaks, Mares says.

Other products in the works

Several other companies also have insecticides targeting Asian citrus psyllid in the works.

Phil Stansly, entomology professor at the University of Florida's Southwest Florida research lab in Immokalee, has tested many new psyllid control products in field trials.

Like Dow's Closer, Sivanto (flupyradifurone), under development by Bayer Crop Sciences, is similar to neonicotinoids.

Stansly says both products will be useful as foliar sprays to save neonicotinoids for soil drenches.

Nichino America Inc.'s Apta (tolfenpyrad) fits into IRAC's Group 21A insecticides.

"It's considered a miticide, but it looked quite good" in trials, Stansly says.

Marrone Bio Innovations is developing a microbial bio-insecticide derived from Burkholderia bacteria. It kills psyllids and may cause less collateral damage to beneficial insects than many conventional insecticides, he says.

More products aid resistance management

Expanding the number of available modes of action gives growers more options to rotate chemistries during the growing season, a necessary step for resistance management, Stansly says.

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Stripped Mealybug    
March, 10, 2013 at 12:02 AM

Did you know the stripped mealybug also transmits HLB according to new reports from the Univ of Fla. Good luck. Resistant tree now or it will all come to an end quickly.

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