I’ve had issues in the past with slugs devouring my greens (kale, chard, tatsoi, etc.) so for the first I time I tried a row cover this year. I’ve done a couple of nighttime checkups and somehow slugs have still made their way into the raised bed with greens in it (!), but there seems to have been slightly less overall insect damage. However, it seems to be getting very hot and humid underneath the row cover (especially with this past Northeast summer) even though I’m using the lightest “summer weight” material I could find. Almost all the leaves have the appearance seen in these photos: I’m not sure if it’s a fungus or something else, possibly related to it being so hot and humid under the row cover. I even noticed the same leaf appearance on a fall radish crop I planted about a month ago: the third image included below. I look forward to your help with the diagnosis/treatment. Thank you in advance!
Lots of small spots all over Chard leaves and other greens (under a row cover)
- Thread starter robrocke
- Start date
This resembles Thrips (Thysanoptera) damage, but other insects are possible. You should try to make a positive diagnosis. Go out with a hand lens and examine numerous leaves. Sometimes it helps to go out with a hand lens and a flashlight an hour or so after dark. Thrips usually appear as minute narrowly elliptical-shaped insects.
Row covers can be a two-edged sword, preventing some problems but making others worse. If you have a problem with slugs, I'd recommend beer traps, hand picking. and modern molluscicides such as Sluggo and New Formula Corry's, which are now much safer to non-target organisms than earlier slug baits. Don't discount hand removal. Done regularly in a small somewhat confined area such as raised bed, it can be work very well.
With leafy edibles, prevention or early detection are the workable answers, as such damaged leaves are not appetizing to eat, but do what you can. Also remember, it is now mid-October and your vegetables' days are numbered. Insect damage can become rampant towards the end of a season, as annual plant's growth and innate defenses begin to shut down. Be sanitary, and tidy up, mulch, and/or cover crop your bed in winter so that it will be in largely pest-free when the season starts in Spring.
Row covers can be a two-edged sword, preventing some problems but making others worse. If you have a problem with slugs, I'd recommend beer traps, hand picking. and modern molluscicides such as Sluggo and New Formula Corry's, which are now much safer to non-target organisms than earlier slug baits. Don't discount hand removal. Done regularly in a small somewhat confined area such as raised bed, it can be work very well.
With leafy edibles, prevention or early detection are the workable answers, as such damaged leaves are not appetizing to eat, but do what you can. Also remember, it is now mid-October and your vegetables' days are numbered. Insect damage can become rampant towards the end of a season, as annual plant's growth and innate defenses begin to shut down. Be sanitary, and tidy up, mulch, and/or cover crop your bed in winter so that it will be in largely pest-free when the season starts in Spring.
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