Last week, I suggested the use of DMIs (Quash, Indar, Inspire, Rally, etc.) for brown rot control spray program. A fellow reader shared some experiences with me regarding the use of DMI fungicides during the late bloom period. Although DMIs are good for brown rot, anthracnose, and have some activity against scab, shothole and rust, they do not provide control for the fungus Botrytis, which causes jacket rot and green fruit rot (Photo above). Botrytis is found everywhere and grows rapidly in cool, moist weather. It typically infects young almond jacket and fruit, causing infection and nut abortion. It is greyish in appearance, and affects varieties that cluster – Avalon, for example. It is not found frequently, but when found, is typically in orchards that have only used DMI fungicides. Therefore, if your last fungicide application is a DMI, I would advise to include a broad spectrum as a tank mix (chlorothalonil, Captan, Maneb, Rovral) to help reduce the incidence of Botrytis infection.
Any other thoughts on this?
Almond Bloom Spray Considerations - The Almond Doctor
December 30, 2014[…] 8. Remember that DMIs (FRAC 3) fungicides are not very effective for jacket rot, a disease that is comm…s. […]
Almond Bloom 2015 - The Almond Doctor
February 8, 2015[…] warmer temperatures for Brown Rot, Anthracnose, Bacterial Spot, and Shot-hole, cool weather for Botrytis, and heavy dew. Fungicide selection should provide coverage for the diseases of concern (Please see […]