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Photo by © Galinasavina | Dreamstime.com
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By Emily Carmichael
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Photo by Caroline Teasdale
Lygus nymph, lygus pierce and suck the fruit causing distortion.
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Larva in Albion
Larva in Albion
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Photos by Caroline Teasdale and Sarah Busch
Strawberry pest damage
Damage to strawberries by powdery mildew (left) and thrips (center and right)
With the increased planting of day neutral strawberries, growers are facing pests that are familiar, but more persistent. Emily Carmichael, berry IPM consultant with E.S. Cropconsult spoke to O&V about the pests most frequently invading day neutral berry patches.
“These are pests that are all present in the June bearing fields, but they are more of an issue in the day neutral fields,” noted Carmichael.
Specifically, she identified thrips, lygus, spider mites, SWD and powdery mildew as issues with thrips and lygus being two of the major concerns.
“They all impact the plant or fruit in some way,” she said.
There are multiple reasons for the increased dominance of these pests in day neutral strawberries, one of which being the structure of raised beds because they are not renovated or mowed at the end of each season. Also, because of the longer harvest season, any pests that have taken hold have the opportunity to increase in volume and wreak greater havoc.
While all of the pests hit maximum levels in August and September, thrips, lygus and spider mites begin their obnoxious journey through the fields as early as May. SWD tends to become an issue in late July or early August while powdery mildew establishes itself in June.
Thrips will dry out the berries, or cause a rusty looking exterior. At present, Delegate is the only chemical product registered for thrips on strawberries and the IPM solution is the minute pirate beetle. Avoid planting strawberries near grass or hay fields as thrips will move to the strawberries when these areas are mowed.
Lygus pierce and suck the fruit causing a distortion sometimes known as “monkey facing” or “cat facing”. Spider mites impact plant vigor by feeding on leaves creating unwelcome pressure on yields. White speckling on the upper surfaces of leaves often indicates spider mite feeding. SWD contaminates fruit as it begins to ripen resulting in overly soft, mushy and/or dripping fruit.
While not an insect, powdery mildew can distort or kill flowers, impact pollination and may prevent fruit ripening. If ripening berries are infected, they have a fuzzy, creamy appearance and will taste bitter.
While Carmichael pointed to thrips and lygus as major pests in day neutral strawberries, she did add that regular monitoring of fields throughout the season improves the ability to control pests and maintain fruit quality. ■