July 30 Berry Bulletin

In this bulletin:

• Crop Update
• Spotted wing drosophila monitoring
• Tissue sampling

Strawberries:

Malwina is finished and renovation is ongoing as growers mow and apply herbicides to June-bearing strawberries. Make sure renovated fields are in good condition by mid-August for flower bud initiation. New fields are variable at this point, some are looking great and growers are training runners while other fields are slower to get going. Spring-planted day-neutrals are starting to be picked across the province.  

Insects:

Spotted wing drosophila is active in all areas we are monitoring and all growers with ripe fruit should be managing for SWD. See below for more information. Regular harvest in day-neutrals is a very effective tool to help manage SWD.

Continue to monitor for potato leafhoppers, two-spotted spider mites, and tarnished plant bugs in day-neutrals.

Potato Leafhopper: ‘Hopper burn’ can be found in many day-neutrals and new June-plantings.   Watch for leaves that are curled down with yellow or pale green leaf edges. Confirm damage is caused by leafhoppers by looking on the underside of leaves for nymphs.

• Control may be necessary in new June-bearing fields and in day-neutrals.
• In new plantings choose a product that will control leafhoppers and aphids, such as Sivanto Prime, Assail, Cygon or Lagon.
• Aphid numbers are fairly low right now but aphids need to be managed every 2-4 weeks if you are not monitoring for them- there is very low tolerance for aphids in new fields.  
• Cormoran and Malathion will control both leafhoppers and SWD in day-neutrals.
• Also monitor for two-spotted spider mites and potato leafhoppers in day-neutrals.

Cyclamen mites: Renovation is a good time for cyclamen mite control. If there is a history of cyclamen mites in your field or you can see symptoms in the leaves that are growing back now is a good time to apply a miticide, while it is easier to reach the mites without a large canopy.

• Agri-mek and Vegol Crop Oil are your only options for cyclamen mite control.
• Rotating between Agri-mek and oil is a good practice for resistance management.
• If you are not controlling for cyclamen mites after renovation keep an eye on the field in September or early next spring for damage and to time the next spray.

Disease: Once picking begins in spring-planted day-neutrals growers have more limited fungicide options for anthracnose control. Include a product that will control powdery mildew, botrytis and anthracnose in your spray program. For anthracnose control during harvest:

• Rotate between Switch (12 + 9), Diplomat (19), and Quadris Top (11 + 3). Keep resistance management in mind.
• Use Switch during periods when conditions are highly favourable for anthracnose infection (warm, humid weather + splashing rain).
• Note there is a maximum of 3 applications of Switch per year. (Do not make more than three applications of fludioxonil-containing products (eg Switch, Miravis Prime, Scholar) on strawberries per year.)
• Add a fungicide to Quadris Top for Botrytis control.  
• Diplomat is registered for suppression rather than control of Botrytis and powdery mildew. Tank mix Diplomat with compatible fungicides for additional botrytis and powdery mildew control

Blueberries:

Harvest continues with a good crop. Watch for Japanese beetles. Exirel will control Japanese beetles and SWD. Malathion also has some activity on Japanese beetles. Note the new, higher rate for Malathion: 1000-2500 mL/ha in blueberries.

Spotted Wing Drosophila:

SWD has been caught in Essex, Elgin, Norfolk, Haldimand, Middlesex, Oxford, Niagara, Halton, Hamilton, Hastings, Prescott & Russell, Renfrew county and Northern Ontario.

Berry crops with ripe fruit are at risk, and all growers should maintain a regular spray program if there is ripe fruit on your farm, including in day-neutral strawberries and blueberries. 

• Spray every 5-7 days. Note there is a new rate for Malathion: Changes to Malathion 85E label for SWD management in berry crops and cherries.
• SWD numbers could build up quickly with the regular rains we’ve been having and the more moderate temperatuers in the forecast. It is very important to maintain insecticide coverage.

• Reapply after ½-1 inch of rain. For more information on the rainfastness of insecticides check out this article from John Wise at Michigan State University: Rainfast characteristics of insecticides on fruit For example, Malathion and Delegate do not have sufficient residue after ½ inch of rain for SWD control on blueberries.

Tissue sampling:

• Late-July to early August is a good time for tissue sampling for a nutrient analysis in strawberries, raspberries and blueberries. Check out this article for more information on what and how much to sample:  Summer is the Time for Leaf and Petiole Sampling.