4th September 2023

FEWER existing insecticides for combatting escalating populations of scale and long-tailed mealybug in grapevines, combined with crop timing restrictions with other options, has created concern over the control of these species for growers. However, new insecticides are becoming attractive in control programs and are adding welcome flexibility to assist vineyard productivity.

Both insects feed directly on the vine sap, excreting a honeydew substrate that supports the growth of sooty mould, a wine taint that downgrades fruit value.

Scott Paton, Horticulture Product Development Agronomist with Nutrien in Western Australia, said the crop timing windows for some products didn’t always coincide with the ideal insect development stage for treatment and this was causing some control challenges.

“The products we have had access to control parts of the lifecycle, and if the timing doesn’t line-up and you are relying on its residual control profile, then you are getting minimal effect from the spray treatment,” Scott said.

With some traditional insecticides also no longer applied in vineyards, he said growers now had to be more targeted with new options to achieve optimum control of these insect populations, and one of those options was the dual mode of action insecticide, Trivor, from ADAMA Australia.

In WA, long-tailed mealybug management is the main focus in table grapes in the Swan Valley and winegrapes in both the Margaret River and Swan Valley regions.

Scott said the long-tailed mealybug was a major problem in table grape crops and can require up to six spray treatments, while populations were more seasonally-dependent in winegrapes and generally managed with one to two insecticide applications.

Nutrien has been conducting trials investigating mealybug management in both table grapes and winegrapes in WA.

Scott said the trials had looked at the lifecycle of the species and evaluated insecticides, including the recently released Trivor, applied alone and in sequences with other options to help devise the best possible control programs for growers.

He said Trivor had been a strong performer in the trials, showing good knockdown ability, a broad range of activity over the long-tailed mealybug lifecycle and excellent flexibility in relation to application timing and its use in tank mixes with other products, including fungicides.

“It’s providing a good level of control, comparable with market leading options, and it adds a lot of flexibility without sacrificing performance.”

“It can be mixed with fungicides without any issues, which can be a problem with other insecticides. So, it’s a highly efficacious product and it can be used without adding extra passes and complications.

“For winegrapes, it’s massive to cut down on passes and table grapes require a lot of treatments, so the more you can minimise what goes in the tank, the better.”     

Trivor combines acetamiprid (Group 4A) for rapid knockdown and the insect growth regulator (IGR) pyriproxyfen (Group 7C), which provides effective residual control. Together, they also reduce the impact on beneficial insects compared with broader spectrum chemistry.

In winegrapes, Trivor can be applied up to E-L 31 growth stage for domestic wine production and up to E-L19 for export wine, while in table grapes it can be applied up to E-L 25 growth stage.

“Applying a combination of active ingredients for a double hit at populations provides for more reliable control than contact specific insecticides,” Scott said.

“Having an IGR mixing partner with acetamiprid that is highly active and translaminar, and therefore not having to worry about achieving complete coverage above and below the leaf, makes a huge difference for growers and is a big tick for resistance management.

“There is a lot of Group 4 chemistry in use, so we like to see less reliance on it and the combination with other chemistry. We need more chemistry development and to have highly effective options coming forward will be better for the sustainability of grape growing businesses.”

He said the company’s trials had gone into great detail in assessing lifecycle activity with the insecticide treatments and as a result of the strong confidence in the control provided by Trivor, it was constantly being added to programs with both table grape and winegrape growers in WA.

“It has been quickly adopted by the market in the Swan Valley and Margaret River regions. It has been good to work with and rotate with other effective chemistry.”

“There are still some concerns over late control of mealybug, but we will keep looking at new options and sequences with Trivor,” Scott said.

For further information on Trivor, growers can contact their local ADAMA representative or visit ADAMA.com

The information provided in this article is intended as a guide only. Information contained in this article has been provided by the manufacturer and although Nutrien Ag Solutions has taken all due care to provide accurate information in this article, there can be no guarantee that such information is accurate as of the date you read it, or that it will continue to be accurate in the future. You should not rely on the information in this article, and it should not be considered advice. You should seek professional advice regarding relevant factors specific to your situation, such as planting times and environmental conditions. This article does not take into account variable conditions such as climactic conditions, soil type and individual circumstances that may impact performance. To the maximum extent permitted by law, Nutrien Ag Solutions Limited and its related associated entities will not be liable for any loss or damage suffered by any person arising out of any reliance on any information contained in this article.