So you had a poor tomato crop last summer?
Last year's tomato harvest was the worst! I did get enough tomatoes for salads and eating out of hand, but very few for processing (drying and sauce).
Many a gardener experienced problems with tomatoes, potatoes, and to some degree with peppers and eggplants, all members of the nightshade family. The dreaded late blight [phycomycete fungus, Phytophtora infestans (Mont.) de Bary] had attacked. This is the same devastating blight experienced in Ireland during the 1840s when the potato famine led to the mass starvation.
With a cool and wet June and July, conditions were ripe for the late blight*, a highly contagious fungus that made its way to Connecticut and other North East regions, via tomato plants sold by big box stores. Blight spores can travel up to 40 miles in the wind. Within a few days the blight can establish itself and devastate a crop. Damage was most evident late in the season. I had some gorgeous tomatoes ripening on the vine in August. Never got a taste!
Early symptoms of late blight develop on leaflets appearing as half-inch brown blotches. Infected leaves dry up and shrivel. Symptoms include dry, dark brown lesions on stems or petioles (leaf stems). Infected fruit and the undersides of infected leaflets show areas of fluffy white fungal growth.
Soaking the ground around the plants is a better alternative than watering with a hose and wetting the leaves. Watering in mid-day allows the foliage to dry off quickly and is another alternative. Wet foliage encourages fungal growth.
Infected plants should be pulled out and placed in a plastic bag and thrown into the trash. Dispose of any fallen leaves, etc. that may have come from the infected plants. Do not place these plants in the compost!
Few preventative organic products are available. Once the plant is infected there is very little that one can do. There are fungicides based on bacteria** that will, over a period of several days, establish themselves and there are applications that are copper based***.
Several tomato varieties are resistant to the late blight. These are listed along with one or two seed sources. Golden Sweet (Tomato Growers/Thompson & Morgan), Juliet (Fedco/Totally Tomatoes), Legend (Totally Tomatoes), Old Brooks (Totally Tomatoes). Black Krim seems to have some resistance too. Last summer both a friend and I had good luck with this tasty variety. I've not yet tried the other varieties. Cornell is currently developing additional resistant varieties which will be further developed by commercial breeders and seed companies.
If you plan to grow potatoes Elba, is one of the most resistant varieties. Rosa, Kennebec, Allegany and Sebago show some resistance.
The experience of the 09' growing season should make clear the importance of avoiding monoculture practices for our large industrial agricultural farms, home gardens and everything in between. Diverse varieties provide a better chance of more crops surviving unexpected problems. Consider the negative implications of a similar problem on a grand scale and potential impacts on our food supply.
Learn more about the late blight and other gardening issues at Fairfield's Earth Day Celebration at Fairfield Warde High School on May 8 from 10 a.m. to 4 p.m.
*The blight causes fewer problems when conditions are sunny and hot and its spread is contained or eliminated.
** Serenade (Fungicide) is a naturally occurring strain of B. subtilis. The bacteria produce a natural antibiotic that helps crops out-compete the pathogens.
Sonata (Fungicide) is a strain of the bacterium Bacillus pumilus which manufactures a sugar compound that interferes with the metabolism of plant pathogens, leading to the death of the fungi. The bacteria also inhibit plant pathogens from becoming established on crops, while exhibiting little or no disease resistance problems.
*** Copper is very effective but it is suggested that one keeps the amount that comes into contact with garden soil to a minimum. When spraying, a layer of newspaper can be situated/placed around the plants and disposed of afterwards.