Question on tomato blight.
I know humidity and dew/condensation causes blight to spread.
Could laying floating row covers over the tops of the tomato cages prevent the dew from condensing on the leaves?
I was thinking it wouldn’t be necessary to completely cover the plants like for insect and pest control, but just across the top with the sides open, to keep the dew off.
Tomato blight is in the SOIL, so the key to prevention and/or slowing it down, is to mulch your tomatoes well, but leave a gap around the stem for direct watering/fertilizing. Also, pruning your lower tomato plant leaves well above the soil and using a copper spray on the bottom 1/3 of your plants on a regular basis helps knock it back, too.
Humidity and dew really don’t contribute to spreading the disease; heavy rain downpours on un-mulched garden beds can splash the blight up onto the higher leaves, spreading disease. You will almost always see blight starting on the LOWER leaves and working its way UP. HOWEVER - if your tomatoes are packed in and there’s not enough air circulation around them, that also contributes to blight issues.
I know it’s too late for this year, but in the future get in the habit of buying seeds/plants that are blight resistant. Look for AAS Winners; they’re usually a winner because they don’t have the disease issues other varieties have. The AAS Winners listed here are the small and cherry-types.
https://all-americaselections.org/aas-winning-tomato-types/
Here is a listing of blight resistant tomatoes that are newer to the market:
https://www.bhg.com/gardening/gardening-trends/best-new-tomatoes-2020/
Here are some ‘old standards’ many of us have been growing for years:
https://tomatopedia.org/blight-resistant-tomato-varieties/
Disease Resistant Codes (usually listed in the catalog description; sometimes are part of the actual tomato variety name):
Disease Resistance Codes
V Verticillium Wilt
F Fusarium Wilt
FF Fusarium, races 1 and 2
FFF Fusarium, races 1, 2, and 3
N Nematodes
A Alternaria
T Tobacco Mosaic Virus
St Stemphylium (Gray Leaf Spot)
TSWV Tomato Spotted Wilt Virus
I heartily recommend ANY of the tomatoes in the ‘Chef’s Choice’ series - but leave room because the plants and the tomatoes are BIG!
https://tomatogrowers.com/collections/chefs-choice-tomatoes