What a difference a year (and adequate chill) makes. Unlike last year, when peach trees struggled to bloom due to the lack of chill, there is no shortage of blooms this year. At last observation, (Monday, February 26), several peach varieties in the variety block at the Chilton Research and Extension Center were at full bloom such as ‘Country Sweet’, ‘Glacier’, ‘Goldprince’, and ‘Juneprince’ already there.
Bloom is taking place earlier than in some previous years as well. Though peach blooms are a welcome sight, their earliness this year presents some management challenges.
First, there is always the expectation of a late season frost. Flower buds that have been released from dormancy will be vulnerable to damage.
Secondly, another issue that we may face is blossom blight. Blossom blight is a fungal infection of the peach flower. The same fungus that causes brown rot – Monilinia fructicola, causes blossom blight. Blossoms that turn brown after bloom is an indication of blossom blight.
Blossom blight has not occurred in the area recently or very often over the years but conditions are favorable for an occurrence of this disease. Blossom blight could be an issue where brown rot cankers or mummies were found during pruning.
We are almost certain to see an increase in the number of mummies left on trees because of changes in tree management due to lack of chill experienced last season. These mummies will serve as additional sources of inoculum and hasten the spread of blossom blight or brown rot.
According to the 2018 Southeastern Peach, Nectarine, and Plum Pest Management and Culture Guide, spay options for blossom blight are captan, chlorothalonil, thiophanate-methyl plus captan, Rovral and Vangard. Again, Topsin M should always be combined with Captan. Consult the pest management guide for rates and cautions.
If there should be a need to prune after pesticide application consult the pest management guide on worker safety, which can be found on page 11. The pest management guide also suggests that insecticides not be included in tank mixes during bloom in order to protect pollinators.