Managing diseases such as powdery mildew and risk of resistance in grapes and apples is made more effective by rotating chemistry with different modes of action.

Esteem, a new fungicide from Lonza, utilises the active ingredient polyoxin D zinc salt from FRAC group 19, the only active in this group. This novel fungicide provides effective powdery mildew control in both apples and grapes, with the addition of Botrytis suppression in grapes.

“Powdery mildew is a major disease in both pipfruit and viticulture,” says Lonza Technical Services and Development Manager Stephen McKennie. “Crop protection solutions that offer a different mode of action to existing chemistry are worth considering as part of a robust control and resistance management programme.”

The active ingredient in Esteem stops the production of chitin and prevents glucosamine from being incorporated in the fungi cell walls of the target diseases.

The way in which Esteem inhibits chitin biosynthesis is a different biochemical pathway to chitin production in insects and crustaceans, meaning the product has a favourable safety profile with beneficial insects.

Best use guidelines:

• Apply Esteem soon after first signs of the disease and reapply within seven to 14 days.
• Use the shorter spray interval during periods of rapid growth, after significant rain or increased disease pressure.
• Make no more than two consecutive applications of Esteem before changing to a fungicide with an alternative mode of action.
• Up to four applications of Esteem can be used in one season.
• Esteem can be tank-mixed with a range of other crop protection products.

Esteem is exempt under minimum residue level requirements with a 1-day pre-harvest interval (PHI). However, check with your exporter for the relevant PHI if needed.

Stephen adds: “The use window of Esteem in apples is typically November, when fruit are 20 mm in diameter, onwards to pre-harvest. In wine grapes, it typically fits later in the season due to its short PHI.”

Find out more about Esteem from your Fruitfed Supplies Technical Horticultural Representative.