Cornell Coop Ext.'s Advice to limit late blight organically

[clear eye]

http://www.extension.org/article/18361

I know my timing is lousy, but if you bookmark the article's page, you can refer to it next year.

[beac]

1. Thanks for the link. Bookmarked. n/t

[bvar22]

2. Thanks for this post

Late Blight of Tomatoes is a problem here.
In Central Arkansas, we have HIGH humidity with dripping dew every morning, and have experienced "Late Blight" (early Summer) in our tomatoes, as well as fungal and mold problems with other crops.

For tomatoes we did several things this year that have had "some" beneficial effects:

1) Instead of planting tomatoes together in a clump, we spread the tomato plants throughout the garden reducing transmission from plant to plant. This has been effective. We have two plants that show some signs of Late Blight, but others that remain healthy.

2) The infections seem to occur initially on branches that are near the ground, or especially touching the ground. We have pruned low branches and encouraged the plants to grow UP instead of out. This also encourages more air circulation. We were somewhat experimental this year, but will do this aggressively next year.

3) We immediately prune off any branches that show brown or yellow spots and remove them from the garden area. The host plant is already infected, but this seems to slow the progression, and may impede the spread to other plants.

4) Last year, I tried to nurse along infected plants with little results.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=246x10193
The tomatoes harvested from these weak plants were disappointing.
This year, we have started some seedlings for a "late" planting in a bed that had no tomatoes this year. Our new approach will be to pull them up, get them out of the garden, pant new seeding and hope for a late frost.

5) We no longer compost ANY plant that has shown any symptoms of fungus or disease. This differs from the linked article, but we believe that the safety factor more than outweighs the limited benefits of a few plants added to the compost.

6) Heavy Mulching
I have red that most fungal infections originate in the soil. It also seems that this year, the blight we experienced first occurred on leaves that had been splashed with soil from a heavy rain.

This is just anecdotal testimony, but we have had fungal problems with other plants, most notably cucumbers and cantaloupes. This year, we planted cantaloupes, and added a heavy layer of hardwood mulch. The cantaloupe plants have almost no contact with bare earth.

That is the cantaloupes in the small white cups.
A stout trellis was added later, and the vines were kept off the ground.
We have had a great year for cantaloupes. Unlike last year, we have healthy, strong, green, unblighted plants going strong into August.
Best tasting cantaloupes ever.

Next year, we will use this method with out tomatoes.
We are going to cover the bare earth with newspapers, and plant the seedling through a ssmall hole in the newspaper, then cover with a straw mulch.

All of the information in this post is purely personal experience specific to our garden.
Your mileage could vary.