Spray and harvest – new zero day withholding period for GF-120

Ripe fruit on harvest day is possibly the most attractive breeding ground for fruit flies, says FruitFly Africa’s manager, Nando Baard. Therefore the amendment for the use of GF-120 to a zero-day withholding period is a great improvement in controlling the pest.

“It came to our attention that there was a one day withholding period for Spinosad (the active chemical compound in GF-120) as set out on the label. That meant that after application there was a 24 hour waiting period before harvesting could start. This would greatly hinder effective area-wide fruit fly control, as ripe fruit is the ideal breeding ground for fruit flies.”

FruitFly Africa, along with other industry bodies, requested that Dow AgroSciences apply for a zero-day withholding period on this product. This resulted in a two-year joint effort by FruitFly Africa and Dow AgroSciences where multiple fruit samples were collected for residue analysis from several areas and provinces. The label for GF-120 has now been amended to a zero-day withholding period.

Technically this means that GF-120 can be applied on the same day as harvesting, says Baard. According to Baard not covering orchards until harvest day could lead to hotspots where fruit fly populations could grow and migrate to other orchards later the season. “If the one day withholding period stayed as it was, these orchards could not necessarily have been baited on the day of area-wide application.”

For the better part of a decade, South Africa has been using area-wide integrated pest management (AWIPM) programs to suppress fruit fly populations in various fruit producing areas. With the support of the National Department of Agriculture, Forestry & Fisheries (DAFF), FruitFly Africa (FFA) has been able to implement these strategies with relative success through the following practices:

• Monitoring;
• Production and release of sterile males;
• Hotspot management (including host plants and home gardens)
• Ground baiting, including “attract and kill” M3 traps
• Monitoring and treatment of towns
• Communication and Education programme
• Coordinated aerial baiting, including strategic bait applications
• Orchard Sanitation

For the success of this programme, an area-wide strategy is imperative. GF-120 is at present the only fruit fly bait that is registered for aerial application in South Africa and is applied over orchards in all regions where area-wide control measures are in place. Aerial application is also the only means of ensuring adequate coverage and chemical control within an area. Aerial application of GF-120 is thus an integral part of successful AWIPM programs in the deciduous fruit industry.