With a focus on fruit quality, Avoco’s technical team is very familiar with the challenges facing growers on their orchards throughout the changing seasons. As a result of weather conditions this year, many growers are having to deal with an unusually early presence of greenhouse thrip, as well as the normal appearance of leafroller brought on by the warm, humid spring conditions.  

Six-spotted mite pressure has also been heavy in avocado orchards over the last six months. Many growers have largely brought this under control by Winter/early Spring miticide applications.  However, some orchardists are still struggling with the leaf drop that comes with prior infestations. 

Technical consultant Jerome Hardy says growers simply don’t get the ‘longevity of control’ they used to enjoy from the annual application of etoxazole (Paramite, Eromite).

“We urge growers to keep watching their numbers closely. It is now common to see Spring, Summer and Autumn surges in mite numbers, but there are options for tackling these.”

Spray decisions must be informed by pest-monitoring results, Avogreen principles, harvest considerations, phytotoxicity risk and any risk to bees, he says.

As growers put flowering behind them and the growing season starts, Avoco’s technical team recommends a range of products to combat leafroller and thrip.

“Spinetoram, though expensive, gives effective control of both leafroller and thrip when used at the 40ml rate,” says Jerome. “It also means you can save other thrip control options for the summer onwards, when it’s less disruptive to the harvest.”

The with-holding period for Spinetoram (all markets) is 14 days. If there are doubts about bees still foraging in an orchard, growers can safely apply the product in the evening as it is safe for bees once dry. 

Where dealing with significant thrip numbers, growers are advised to apply a follow-up spray 14 to 20 days later, and consider including any Cryptomeria shelter.

Methoxyfenozide (Prodigy, Genoxy) provides excellent, long-lived leafroller control and is the product of choice if growers have leafroller present. Most growers will use methoxyfenozide at least once during the growing season. Though reasonably widely compatible, it’s not advised to use it with oil. The with-holding period for all markets is 14 days.

Emamectin benzoate (Proclaim, Vitis), is not as effective as methoxyfenozide but is useful if growers need leafroller control just prior to harvest. This is because the with-holding period for all markets is only three days.

“Thiacloprid (Calypso, Topstar, Alpasso) is still the stalwart of summer thrip control once your first fruit has been picked. It combines well with Abamectin but if applied, growers must be aware of the market with-holding periods which range from 14 to 35 days.”

When combatting six-spotted mite, Milbermectin (MitEMec) is an expensive but useful part of any grower’s control strategy, as it is effective on eggs (ovicidal). However, Jerome says it should only be applied between mid-November and March as the effectiveness is heavily dependent on soft flush and good coverage.

“Use with a high quality, non-ionic surfactant. The with-holding period for all markets is 14 days.”

Abamectin (Avid, Verdex, Invert) should also be an essential part of any grower’s mite control strategy, says Jerome. “It’s inexpensive, provides quick knock-down of mites and also offers reasonable leafroller control.

“It’s also translaminar, so control will be extended if used on soft flush, and it combines well with other sprays, especially Thiacloprid. If weather/soil moisture status allows, growers can use it with 0.5% oil.  Note that it’s not ovicidal so numbers will bounce back quickly; be prepared to repeat. The with-holding period for all markets is 14 days.”

For more advice on summer pest control, please contact Avoco’s technical team: technical@avoco.co.nz.