Protecting Fruits from Disease

We've certainly caught up with moisture for the year during this past month. I'm sure most would like to see some sunshine and warm weather. I'm not sure we've had the combination of these two for many days this spring. But the grass in the lawn is certainly enjoying the weather.

For most crops, the rains have been good. They've recharged the soil profile and set us up well for summer. But for some areas and some soils, the rains have been excessive, resulting in an inability to plant and in some cases the need to replant due to cool and wet soil conditions not being favorable for survival or germination of seeds.

Rain and/or moisture is also critical for disease development, and we're seeing some appear now. I've had several calls on anthracnose of strawberry as well as botrytis (gray mold) of strawberry. It's funny that both these diseases are showing this year as each one has a different optimal temperature range. Anthracnose loves warm and wet, while gray mold loves cool and wet. But since we've had both this month, we can find both diseases.

Anthracnose appears as small dark spots on the fruit that can enlarge and spread over the berry. These spots are shrunken. Gray mold is a properly described disease, as that's what the berry will look like: gray and fuzzy. Both these diseases need to be protected against early in the year. In the case of anthracnose, protection during temperatures above 80 degrees and rain is necessary to developing berries. Gray mold prefers temperatures in the 60's, with wet conditions.

All other fruit crops (apple/peach trees, blackberries, etc.) also succumb to certain diseases during wet weather. And I've also noted insect injury in unprotected fruit trees lately. It's virtually impossible to protect against disease in the humid Midwest without the use of fungicides (even organic producers utilize fungicides). In some years, when disease pressure is low, we don't have many issues. But in years which rainfall and/or humidity is high (which greatly favors disease development) sometimes a whole crop can be lost to disease pressure. You can make the decision if you wish to protect your crop or not. For those who do, we've placed our homeowner spray guide for fruit crops on our site for easy access.