Jun 15, 2023
We've had some detections of leaf spot in strawberry these past few months, and while it's not expected to be of economic importance, it's still worth the while to talk about with strawberry growers.
Strawberry leaf spot is caused by the fungus Mycosphaerella fragariae and is marked by lesions of a few millimeters wide, each having a white center and purple margins, as demonstrated by this recent photo (Photo 1 below) taken recently in Santa Cruz County. While in serious situations or very susceptible varieties these lesions can coalesce and kill the leaf, we have to date not seen this on the Central Coast.
Because of our heavy rainfalls this past winter and then again 0.15 inches last week in combination with the warmer weather of this time of year, and given that spore germination of Mycosphaerella fragariae is maximum at 98 to 100% relative humidity, it is not surprising that we are seeing a bit of this disease around this year.
So readers don't mix this disease up with the more common leaf blotch caused by Zythia fragariae , we've included a photo (Photo 2) below.
Attached Images:
