Bacon County Ag Update

Blueberry Rust

Blueberry Growers, please read this post from Dr. Brannen regarding blueberry rust. Be on the lookout for this disease in your fields as a severe infection of this disease can cause early defoliation. Be sure to stick to your fungicide sprays as seasons continues. Here is the post below.

We have had quite a few inquiries relative blueberry rust over the last couple of weeks (see attached photo of early rust on ‘Rebel’ from Bob Boland). Due to the earliness of the rust observed in blueberries and other commodities at this time, the rust epidemic may increase in importance as we go into the summer. Commercial blueberry producers should be made aware that rust might be a problem this year, and on some varieties it can result in early defoliation, possibly impacting yield and berry quality next year. Producers should be scouting at this time for rust; leaf spot sprays (Septoria and Anthracnose leaf spots) are generally initiated in late May or early June in most years anyway. The same mentioned fungicides will help with rust and these other leaf spots. Recent weather conditions have provided good infection conditions for rust and other foliar diseases. If premature defoliation occurs (before November in the southern part of the state), then next year’s yield could be reduced.

The strobilurins (Pristine and Abound/Azaka [generic product]) and DMI fungicides (Quash, Orbit, Indar, etc.) have activity on rusts. The PHIs on some of the fungicides are as great as 30 days, so read the labels before application, and please keep the PHIs in mind. Bravo (chlorothalonil) can be used after harvest, but NEVER use Bravo on fruit, as it will cause phytotoxicity! The blueberry IPM guide at www.smallfruits.org provides information on specific fungicides for rust and other leaf spot management.

*FYI The product Abound has lost its patent this year. So generics are being made, here is an example from Cheminova which now has a registered azoxystrobin product for many small fruit commodities.  See attached for the AZAKA Label.  Not sure of the price difference for this generic product.

Rust (3)