Friday, July 23, 2010

late blight alert

I was disappointed to hear that late blight has been spotted in Massachusetts (links below) this week. On Tuesday, it was found on tomatoes in a field in Hadley MA (Hampshire County, western MA). Tests are being done to figure out where it came from.

Its also been found this year in a garden in Maine, and on commercial potatoes in Wisconsin.

I have been looking at tomatoes and potatoes in our plots and have yet to see any late blight.

UMASS late blight site
Cornell late blight site.

11 comments:

kibbles said...

Yikes. I am suspicious of some yellow and brown leaves on the lower parts of my plants but nothing has moved upwards or toward the stem, the tomatoes are healthy and everything except a few nasty leaves is okay. I am hoping that is not blight and it's just normal decay. I live in Upstate NY and my plants were affected last year, but they were in pots.

Zazu Ta said...

Hi Kathy,

Would you know of a web site that has good information on complimentary cropping?
The seeds I sowed 2 weeks ago are now gorgeous young plants. I have been going through information on the web... but end up confused more often than not! :(

would really appreciate it. Thank you~

kathy said...

I like the book "Great Garden Companions: A Companion-Planting System for a Beautiful, Chemical-Free Vegetable Garden" by Sally Jean Cunningham.

There are a bunch of good sites too. Here's a nice Cornell Coop site with companion planting charts.

kathy said...

Kay,

Like you said, nothing on the stems. And no nickle sized moldy looking spots on potatoes or tomatoes.

I'm also seeing tomato leaf spot and yellowing of lower leaves. These are less aggressive fungi (Septoria leaf spot and others). You can remove those nasty leaves and it will help with airflow.

Anonymous said...

I am in central IA and Early blight has taken a severe toll on my tomato crop. I would say that 3-4 of my 8 plants are almost completely gone.

Because of Garden size and tomatoes are my staple crop I have had increasing incident each of the past 3 yrs with early blight. I cant rotate completely out of the areas where tomatoes were planted previously. I try to mulch soil heavily with grass clippings and select resistant varieties of plants from the store.

Other than weekly treatments what else can I do in the future to help control early blight??

kathy said...

Airflow: Make sure your plants have good air flow. Its best to stake them straight up along a pole or string and remove suckers. This allows maximum airflow. Also plant the plants with good space between them. I've also seen gardeners who like to remove the lower leaves as the plants grow to increase airflow.

Reduce water on the leaves: I've recently seen gardens with clear "roofs" over the top of tomatoes to keep water off the leaves. Its better to water with a soaker hose or underground irrigation system to keep water off the leaves. And water early in the day so the leaves will dry.

Copper sulfate spay is OK in organic gardens and will slow the growth of fungal pathogens. Bacillus subtilis also.

You can also look into stronger fungicides if you are not organic.

http://ccesuffolk.org/assets/Horticulture-Leaflets/Early-Blight-and-Septoria-Leaf-Spot-of-Tomato.pdf

Ashlee said...

I read your previous post about Basil Blight, and was absolutely certain I would get to mine in time... However, my entire basil crop was lost to the blight. Keep an eye on yours. The blight took over just after the flower heads started to form.

kathy said...

Thanks! Good advice. My crop is ready to cut and I should do this sooner rather than later. Tomorrow would be good. There are some discolored leaves in one area that look sort of like sunburn.

Sorry to hear about your lost crop :(

B.Eckert said...

I'm in Vermont and I noticed some spots on my tomatoes yesterday. Immediately I thought of blight since we got crushed last year. However, the fungi that you mentioned might be it. I'll remove those leaves and hope for the best!

Anonymous said...

We just pulled up seven Black Sea Man tomato plants because of the beginning of blight. We're in Northern Essex County, near the NH border. We grow all our 'matoes from seed, and no nearby tomato growers, so it's arrived in the air from somewhere.

kathy said...

Very disappointing to hear. Sounds like its gradually spreading out.

No sign here yet. I will watch.

Thanks!