Young leaf lesions are small and appear as dark, water-soaked spots. Late blight is especially damaging during cool, wet weather. Late Blight is a potentially serious disease of potato and tomato caused by the fungus Phytophthora infestans. When managing bacterial spot as well as other bacterial diseases, it is important to keep in mind that bacteria readily multiply and spread under warm wet conditions. Young bacterial spot foliar lesions can be difficult to distinguish from those of early blight. This may be due in part to the increasing frequency of severe weather events that favor disease development. Not only can the pathogen directly damage the fruit, severe foliar infection can lead to defoliation reducing both the quality and quantity of the fruit. Photo Credit: Penn State Master Gardener Program Bacterial Spotīacterial Spot is becoming an increasingly devastating disease of tomato. The fungus is not soil-borne, but can overwinter on residue from previous crops, decaying vegetation, and some wild hosts related to tomato. The fungus is most active when temperatures range from 68 to 77☏, the humidity is high, and rainfall or over-head irrigation wets the foliage. Severely spotted leaves turn yellow, die, and fall off the plant. Spotted leaves die prematurely, resulting in early defoliation, fruit sunscald, and poor fruit flavor and color. Like early blight, Septoria leaf spot symptoms usually start on the oldest leaves. Early symptoms are usually dark spots, eventually, the center of the spot becomes whitish to tan, sometimes with tiny, dark specks (spore-producing bodies). Infection usually occurs on the lower leaves, after plants begin to set fruit. Septoria Leaf Spot is a destructive disease of tomato foliage, infecting the petioles and stems by the fungus Septoria lycopersici the fruit is not affected. Do not remove more than 20% of the plant's total leaf mass. Disinfect clippers in a solution of one-part Clorox bleach to nine parts water. At the first sign of early blight, prune off all leaves within 12 inches of the ground. Remove and properly dispose infected lower branches and leaves-do not compost. Eradicate weeds and volunteer tomato plants, rotate crops, space plants appropriately so they do not touch each other, mulch and fertilize properly, and avoid wetting foliage with irrigation water. To prevent early blight, plant disease-resistant tomato cultivars. Concentric rings are also present on the fruit. On the fruits, lesions reach considerable size, usually involving nearly the entire fruit. Lesions on the stems are similar to those on leaves and sometimes girdle the plant if they occur near the soil line (collar rot). If warm temperature and humidity occur at this time, much of the foliage is killed. In most cases, early blight damage will be limited to the lower third of the tomato plant. As the spots expand, tissue surrounding the spots may turn yellow. These spots enlarge and concentric rings in a bull's-eye pattern are visible in the center of the diseased area. The fungus is first observed on the plants as small, brown lesions mostly on the older foliage. Photo credit: Penn State Master Gardener Program Low leaves that drip with morning dew provide perfect conditions for early blight.Įarly Blight. The fungus needs a wet surface to germinate and grow. Spores can spread to tomatoes in spring via wind or splashing rain. Prevalent throughout the United States, the fungus survives on infected debris in the soil, on seed and volunteer tomato plants, and other solanaceous hosts, such as Irish potato, eggplant, and black nightshade. Early blightĮarly Blight is caused by the fungus Alternaria solani, which is present worldwide wherever tomatoes are grown. ![]() Corn, an excellent rotation crop with tomatoes, supplies large amounts of organic matter and does not promote the growth of disease organisms that attack tomatoes. Ideally, any cover crop or crop preceding tomatoes should be members of the grass family. Tomatoes and related vegetables, such as potatoes, peppers, and eggplant, should not be planted in the same area more than once in three years. A good amount of organic matter will increase yield and reduce production problems. Tomatoes ( Solanum lycopersicum) can be grown in almost any moderately well-drained soil. Whether tomatoes are grown in pots, raised beds, or in a truck patch, homeowners need to be aware of tomato diseases.ĭisease can strike quickly and be difficult to diagnose. Of these, tomatoes win the prize as the most popular vegetable grown in backyard gardens across America. As vegetable gardeners, we look forward to harvesting armfuls of produce throughout the growing season.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |