The weather is warm, the flowers are blooming, the bees are buzzing, and it won’t be long before we’re picking strawberries.
We’re in a critical disease management time now with Botrytis gray mold being our biggest threat. Gray mold loves temperatures between 62 and 77 degrees and periods of leaf wetness lasting 14 hours or more. Our weather has consistently been in that temperature range recently, though it has been a little dryer. Regardless, we definitely need to be on a spray program now.
Most growers follow a regular spray schedule of every 7-10 days and that works well. Here are two good disease management programs outlined on page 20 of the 2016 Strawberry IPM Guide.
To fine tune your disease management program, you can take a sample of flower buds or leaves that you find with gray mold growing on them and send them to Clemson plant pathologist Guido Schnabel for a fungicide screening test. Dr. Schnabel tests the samples to see which fungicides are most effective at controlling the population of gray mold on individual farms. Specific instructions on collecting samples can be found here.
Keep scouting for spidermites, also. The weather is getting warmer and dryer which promotes rapid mite population growth. Refer back to this post for information and thresholds to keep in mind when making spray decisions. Remember that spraying pyrethroids for will flare spidermite populations because it kills beneficial insects (including bees which you need for pollination) as well as the pests.