Check your fruit for SWD!
In this week’s post: strawberry, raspberry and blueberry crop development, pest management, and spotted wing drosophila update.
PDF available: Berry Bulletin July 20
Crop development: June bearing strawberry harvest is slowing down in Southern Ontario; late varieties including Malwina are beginning to be picked now, but SWD is making for a challenging harvest. Raspberries are being harvested in most parts of the province. Blueberry harvest has and the crop potential is looking promising.
Pick-your-own operations are open and the crop potential is looking good across the province. If you have had scale damage in the past keep an eye out for scale crawlers to time your sprays. It is time to start controlling for spotted wing drosophila in southern, central and eastern Ontario. Managing preharvest intervals can be challenging in blueberries. Spraying blocks of varieties at different times can help, so get a pre-pick spray on later varieties while you are harvesting early ones. Check out the attached SWD registrations (Registration for SWD July 2017 )to plan your spray program now.
Raspberries: Summer fruiting raspberry harvest is underway. As we are finding SWD earlier this year and at higher pressures don’t neglect the summer raspberries- they will need to be managed for SWD this year. Apply insecticides with a short preharvest interval if you can’t pick the field clean every 1-2 days. Keep your fall-bearing raspberries fields clean as well. If you are not harvesting the early berries try to strip off the fruit to protect your other crops and limit the population from building up.
Potato leafhoppers are still an issue in strawberries, day neutral strawberries, and raspberries. Look for nymphs on the underside of the leaves (Figure 1) or the white shed skins of the previous instars. Control for nymphs where present.
Pick-your-own operations have closed across most of the province and renovation is underway. Do not use herbicides when temperatures are over 25C. Do not use Sinbar in close sequence to grass herbicides (Venture, Poast) or Lontrel or 2-4 D. Wait 10-14 days between applications of these products. Sinbar and Devrinol, used for pre-emergent weed control, require 1-2cm rain or irrigation after application.
After renovating you will still need to monitor and control aphids to protect your fields from virus. Once the populations build up again winged aphids will emerge and fly to other fields, potentially spreading virus. Manage aphids in both new and renovated plantings.
Malwina harvest has just begun. The combination of this late variety and early and heavy SWD pressures means strawberry growers may have to control SWD this year. Check for soft, bruised fruit (Figure 1). Pick your berries regularly and remove all unmarketable berries.
Figure 1. SWD damage to strawberries.
What do June-bearing strawberries, summer raspberries and haskaps have in common? They could be targeted by SWD this year, in addition to the usual suspects. The late strawberry and haskap varieties combined with the early, high SWD pressure means that these crops may need to be managed for SWD. If your summer raspberries haven’t historically had an SWD problem, that might not be the case this year.
We have found sustained SWD catches in most of the traps we have set up across the province. If you are beginning to harvest late strawberry varieties such as Malwina consider applying an insecticide, or keeping the field clean with regular, thorough picking and immediate post-harvest cooling to less that 5C or cooler.
Check this blog to stay up to date on SWD catches in the province, and use the attached SWD registrations for 2017 (Registration for SWD July 2017) to plan your spray program.