Raspberry problem

Asked November 22, 2019, 2:26 PM EST

The fruit develops fine but it gets these mummified looking things where it stops growing and turns whitish. I asked at a nursery they suggesed using captan. I cut the plants down to the ground in winter and burn them. I applied the spray to the new growth. What is the problem and how do I fix it. Not all the fruit is affected. Thanks in advance.

Huron County Michigan raspberries

7 Responses

I does not look like botrytis. the mold is not fuzzy. I do not see leaf symptoms of downy or powdery mildew, two diseases that can also dry out the fruit. The leaves look funny in two of the pictures. Narrow. Do you see those symptoms only on plants with the dried up fruit? Do all the plants have dried up fruit or only some of the plants? I will keep looking.

You might find this resource useful.
I didn't see anything useful but you might recognize some symptoms.
Captan is a broad spectrum protectant fungicide.
It is fair against botrytis and poor for powdery mildew.
Powdery is more of a problem under dry conditions. Botrytis and downy mildew like wet conditions.
Are these summer or fall raspberries?

They produce only in the fall when I cut them down in the winter. When I dont they produce some in the summer but mostly in the fall.They get about 6 hrs of direct sun a day.I run a soaker hose every third day for an hour. We are located on Saginaw Bay so we get alot of wind. Thanks Mark

And you do not spray now and this is a new problem? all over or just a few plants?

I only sprayed twice while the plants were developing about a foot tall.Not all the plants and fruit is affected. I was able to harvest some berries. It's frustrating to see the fruit develope and then turn grayish and die. It doesn't get the whole plant just select areas. This has been happening for years not just now.Some years are better than others.Thanks again Rick

Sorry this took so long to get back to you. I still do not think I have the problem figured out. While I see problems in the new pictures you sent I do not see anything that would make the fruit dry out. Two sprays during early primocane growth is not going to protect the fruit. Captan at bloom and again at the end of bloom should reduce a disease problem in the fruit. The Captan should not harm the bees but avoid spraying in the middle of the day when bees are foraging on the flowers. Spray in the early morning or evening when it is cool and bees are in the hive. This should reduce the problem if it is Botrytis fruit rot. Botrytis can infect during bloom and lay dormant until the fruit starts to ripen and then move and infect ripening fruit so the strategy is to prevent the initial infections at bloom.

If it is b fruit rot how many times should i use Captan other than the 2 times you said.