WHAT'S NEW
NEW ACTIVE FOR POWDERY MILDEW AND BOTRYTIS CONTROL IN STRAWBERRIES
Esteem® is a new mode of action fungicide registered for powdery mildew and Botrytis control in strawberries. Esteem contains 52g/L polyoxin D zinc salt in a suspension concentrate formulation. This active ingredient is from a new chemistry group not previously available in New Zealand. “Lonza NZ is excited to be providing berry growers with a new option for disease control” says technical services and development manager Stephen McKennie. “The mode of action of polyoxin D zinc salt (FRAC group 19) stops the production of chitin, which is an essential process for cell wall and membrane development of the disease-causing fungi.” “This active targets the disease at a number of different lifecycle stages,” Stephen adds. As the only active in this group, Esteem is a valuable resistance management tool that can be utilised as part of the crop protection programme. Polyoxin D zinc salt has been tested in the field on strawberries (in New Zealand and overseas) and has shown excellent efficacy and crop safety when used in accordance with the label. Application rate for strawberries is 125ml/100L, as a dilute spray to the point of run-off. 80 NZGROWER : OCTOBER 2021
It is recommended to apply Esteem with a standard nonionic surfactant at a rate of 25ml/100L. Applications can commence once flowering has started, using high volume dilute spray-to-run-off application methods, to ensure full coverage of leaves, flowers and fruitlets. Re-application is suggested at weekly intervals, as required. Stephen recommends that growers use two consecutive applications before using alternative mode of action fungicides, with no more than four applications in total in any single season. Esteem provides control throughout the disease development lifecycle, however the best results are achieved from applications early in the disease development, before symptom expression. Polyoxin D zinc salt has a 1-day pre-harvest interval (PHI), for good agricultural practice. Esteem is exempt under the maximum residue level (MRL) regulation in New Zealand. Polyoxin D zinc salt is a BioGro certified input. Polyoxin D zinc salt has a different biochemical pathway to insect and crustacean chitin production, so it has a favourable safety profile for beneficial insects. Beneficial insect testing to date has included bees, ladybirds, lacewings, predatory mites and the parasitoid wasp Aphelinus mali. For more information on Esteem visit www.lonza.co.nz to find the details of your local territory manager.
