We
want to share an important update regarding our High bush Monilinia monitoring. As
we mentioned in our last blog post, all the mummy berries have dried up and
cannot release ascospores. What we see now, are the symptoms of ascospores damage which were
released earlier in the season.
In
early maturity varieties, shoot blight symptoms such as drooping of affected
shoots, followed by brownish purple discoloration of the upper sides of the
midribs and lateral veins of affected leaves and flower cluster blight can be
observed (Figure 1 and 2). The tufts of grayish conidia appear along the
petioles, midribs of affected leaves, and on the infected peduncle or flower
pedicels. These conidia that are forming on the diseased leaf shoots and flower
clusters will now be spread further by bees, flies, and wind to open flowers
where they will grow down the flower style and eventually form a mummy
berry.
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| Figure 1. Twig and flower blight. |
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| Figure 2. Twig and flower cluster blight. |
- Most of mid and late maturity varieties are clean but a regular scouting of the fields is highly recommended to help plan for next years mummy berry management.
- Usually, fungicide sprays targeted to prevent these flower infections are not cost effective but can be practiced. The pruning of branches is not recommended but the easiest way to prevent further conidial spread would be to simply pick off diseased leaf shoots and flower clusters and drop them to the ground or collect them in a bag. This would limit the spread of conidia that are present now.
