Gardening Articles: Care :: Pests & Problems
Defying Late Blight
by Susan Littlefield
A couple of summers ago, many gardeners in the East were devastated to find their once healthy tomato plants dying within a matter of days. What started as a few water-soaked spots on the leaves and stems spread rapidly until the entire plant collapsed in a heap. The cause of all this devastation was late blight, a disease caused by the fungus-like pathogen Phytopthera infestans, which strikes potatoes as well. (Eggplant and peppers are related to tomatoes and potatoes, but don't show the same susceptibility to this disease.)
The first sign of trouble is the appearance of dark, water-soaked, irregularly shaped spots, about the size of a nickel or a quarter, on the leaves. These spots become covered with a fuzzy white mold on the undersides of the leaves. They enlarge quickly, turn black and kill the entire leaf. The infection then spreads to the leafstalks and main stem, eventually causing the entire plant to collapse and die. Tomato fruits and potato tubers can also be affected. Weather can have a lot to do with the severity of the disease in a particular season, and gardeners are eager for ways to help prevent a large scale outbreak when conditions are ripe for the spread of the disease.
While there is no tomato variety that is immune to this problem, Johnny's Selected Seeds has released a new variety that is highly resistant to late blight.'Defiant PhR' is a mid-sized slicer that not only resists late blight, it also shows intermediate resistance to the fungal disease early blight, as well high resistance to verticillium and fusarium wilts. The medium size, determinate plants produce high yields of 6-8 ounce, deep red, globe-shaped fruits that are smooth and medium firm, with a great taste and texture. These tomatoes are a good choice for container growing, as well as planting in the garden.
For more information on 'Defiant PhR' tomatoes, go to: Johnny's Selected Seeds.