
Biological control of Botrytis and sour rot
With the grape harvest approaching, growers should prepare for potential late season Botrytis and sour rot control.
“There is a great deal at stake and a lot to lose should a late season infection take hold,” says Susie Dalgety, Regional Business Manager for Bayer Crop Science. “But there are limited options available due to the need to produce a crop with a low or nil detectable residue.
“This means, when the crop is close to harvest, the product choice often needs to be one which offers biological control of these significant diseases. Growers will want to ensure they’ve selected the most effective product, and ensure it’s used correctly to get the best return on investment.”
Of the available biological control products, Serenade® Optimum stands out as an highly effective option with its optimised fermentation product of the QST 713 strain of Bacillus subtilis.
“And while there are other strains of Bacillus subtilis, there is a tremendous difference between these strains with the QST 713 strain being unique in how it controls the target diseases.”
Unlike other Bacillus and biological products, Serenade Optimum does not rely on niche exclusion or colonisation to control Botrytis and sour rot. Its highly optimised and well controlled fermentation process produces lipopeptides which work by disrupting pathogen cell membranes which inhibits spore germination and lyse-growing mycelia to deliver contact fungal control.
Marc Fox, Horticulture and Biologics Product Manager for Bayer Crop Science, says, “Serenade Optimum does not rely on colonisation, so it is able to be tank-mixed with a range of products, and they will not interfere with the mode of action of Serenade.
“A further benefit on top of its unique biological contact activity is that Serenade Optimum can be used right up to harvest as it has a nil residue profile and no pre-harvest restrictions. All these benefits make Serenade a very flexible option.”
To get the best return on investment when using Serenade Optimum, it is important to apply according to the recommendations:
- Always apply preventatively at a rate of 1.25 to 2.0 kg/ha.
- Make two to three strategically timed applications prior to infection periods, at seven to ten day intervals, four to six weeks from expected harvest.
- Use a shorter interval and higher rate when conditions favour rapid disease development.
- Use sufficient water to ensure complete coverage of the bunch area.
- Always add an adjuvant, such as Du-Wett®, to ensure complete coverage.
Serenade Optimum is not limited to pre-harvest use and can be applied at any time during the growing season and is compatible with a wide range of products. It also classed as ‘novel’ meaning it has a low resistance risk mode of action designated by FRAC with the FRAC Code 44.
ACVM registration number: Serenade® Optimum #P009409. Read label before use.