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Plum Curculio and Scale Update

Plum curculio adult.

I posted last week about scale management, but I wanted to send out a reminder about scale and an update for everyone that plum curculio (PC) adults are also active in the orchards (see image above taken last week). In blocks that still have fruit, if you are and have been on top of your cover sprays, there should not be too much to worry about for PC.

San Jose scale settled on peach and close-up of the scale (white dot).

The heat this past week has likely slowed down San Jose scale development beyond what I originally anticipated. We are seeing movement of scale to the fruit (see above image), but peak crawler activity in middle Georgia is expected to occur within the next week or so. Scale crawler activity can me monitored with electrical tape and double-sided tape (or vaseline).

With the overlap of San Jose scale and PC activity, there is an opportunity to synergize management efforts for these pests. Please note the PHI for the listed chemicals

In blocks with fruit on the trees, a combination of Imidan (3.5-4 lb; PHI=14 day) with Esteem (6 oz; PHI=14 days) or Centaur (34.5 oz; PHI=14 day) is likely our best (albeit expensive) option, with high efficacy for both PC and scale. Alternatively, with input from Dan Horton, another effective option is to tank mix Esteem or Centaur with either Belay (6 fl oz; PHI=21 days), Actara (4.5-5.5 oz; PHI=14 days), or Avaunt (5-6 oz; PHI=14 days). I cannot recommend mixing scale chemistries with a pyrethroid at this time, as the pyrethroids will have a larger negative impact on our natural enemy communities that may provide some natural control of San Jose scales.

In terms of scale-only management, Venerate XC (2 qt applied twice over 7 day period; 4 qt total; PHI=0 days), which is most effective when targeting peak crawler emergence, is an alternative option. Additionally, there is Movento (6-9 fl oz; PHI=7 days), but Movento should be applied only if trees are still flushing with new growth, and with the current high temps, Movento may not be the best option during this time period. Lastly, in post-harvest blocks, Dan suggests considering applying 2% summer oil in at least 200 gallons of water/acre.

That is a lot to digest, so please contact me if you have any questions.