Hello fruit growers,
SWD is now being reported in nearby states. Populations
in Vermont can be expected to increase in the near future, with
high numbers typically during the end of July into early-mid
September, depending on your location and local weather.
Here are some reminders about SWD management practices. Using
multiple approaches is important to success.
Harvest fruit very frequently and completely to prevent
the buildup of ripe and over-ripe fruit.
Remove unmarketable fruit from the field and destroy it (bury, send to landfill, cook in clear plastic bags in the sun, etc.) to kill larvae and prevent them from emerging as adults in your fields.
Refrigerate fruit after harvest. Chill berries promptly
after harvest to 32-33 degrees to slow or stop development of
larvae and eggs. Encourage U-Pick customers to do the same to
improve fruit quality at home.
Open the canopy, pruning to increase sunlight and
reduce humidity. This makes plants less attractive to SWD, and
will improve spray coverage. Dry, open conditions reduce the
number of eggs that will be laid in fruit.
Manage irrigation to reduce humidity. Repair leaky drip lines, avoid overhead irrigation to allow the soil or mulch surface to dry.
Monitor for the arrival of SWD. Homemade
or commercial traps (from Scentry or Trécé) can be used to
alert you to the arrival of SWD, and weekly trapping can help
understand what's going on with the population on your farm.
Apply insecticides. Kill SWD adults to reduce egg laying, once susceptible fruits have started ripen (and traps or reports indicate SWD is present). Add 2 lbs sugar/100 gal to increase SWD interaction with pesticides. Add spreader sticker such as 4-16 oz. Nu Film P/100 gal to improve efficacy. Follow label instructions, aligning pre-harvest intervals and your picking schedule. Rotate insecticides by modes of action. Here are lists of labeled materials, conventional and organic, compiled Cornell Extension and UConn Extension.
Monitor the level of fruit infestation using a salt
water flotation test, so you know if your management is
working, what to communicate to your customers, and even whether
to sell fruit.
Good luck! Vern