 |
The Plant Doctor |
|
Host plant name: Tomato, Lycopsericon esculentum, variety name is unknown
Primary symptoms: Plant organs (leaves, stems, fruits) turn black and collapse or rot. Plants can die.
Plant setting: My garden.
Geographic location: Lancaster, Pennsylvania, USA
Number of plants affected: 2-10
Fertilizers used: Miracle Gro fertilizer for tomatoes, used as label directs.
Pesticides used: none
Additional information: This problem developed after we had some cool, wet weather for about 10 days. The disease progresses very rapidly.
Photographs provided:
|
Diagnosis received from The Plant Doctor:
Disease name: Late blight. This disease can spread rapidly during cool, rainy weather, killing plants within a few days and causing total crop loss.
Pathogen name: Phytophthora infestans, classified as a fungus-like organism. P. infestans has worldwide distribution, but most severe epidemics occur in areas with frequent cool, moist weather. The host range of P. infestans is mainly limited to solanaceous crops, including tomato, nightshade (Solanum nigrum), and potato.Many strains of P. infestans have been reported in the United States and worldwide. They vary genetically for virulence and have been able to overcome previously resistant plant varieties (e.g., potatoes), and they also pose the threat of developing resistance to certain types of fungicides. P. infestans infects all aboveground parts of susceptible plants at any stage of plant development.
Disease management:
1. Select a tomato variety that reaches maturity quickly (i.e., early-bearing or short-season types). This will allow the grower to get the crop harvested as soon as possible. "Early-season" tomato varieties require about 55-67 days to reach maturity; whereas "mid-season" and "late-season" varieties require from about 68-78 days and about 79-85+ days, respectively.
2. Grow tomatoes in glasshouses or in spaces where there is humidity control and the plants are covered and protected from rainfall.
3. Ensure quick and vigorous tomato seedling growth though adequate and supplemental plant nutrition. Silicate-containing fertilizers may increase pest resistance,especially in the seedling stages.
4. Harvest early. If your tomatoes are nearly full size (yet green) and there is a big storm coming and you can use green tomatoes, you might as well harvest them.
5. Stake up tomato plants, especially indeterminate types. Keep tomato stems and branches away from the ground.
6. Intercrop tomato with non-susceptible host plants, preferably non-solanaceous plants.
7. Practice good crop sanitation; inspect the plants regularly for late blight disease symptoms and promptly remove diseased material from the plot or garden
8. Eliminate cull piles in the vicinity of tomato plantings.
9. Protect plants seedlings with fungicides that are registered in your area for this crop and disease.
10. Do not plant potatoes near tomatoes, or if potatoes are planted, use a blight-resistant variety.
For more information: contact Lancaster County Cooperative Extension,1383 Arcadia Road, Room 140,Lancaster, PA 17601-3184, Phone: 717-394-6851
Disease name: Late blight. This disease can spread rapidly during cool, rainy weather, killing plants within a few days and causing total crop loss.
Pathogen name: Phytophthora infestans, classified as a fungus-like organism. P. infestans has worldwide distribution, but most severe epidemics occur in areas with frequent cool, moist weather. The host range of P. infestans is mainly limited to solanaceous crops, including tomato, nightshade (Solanum nigrum), and potato.Many strains of P. infestans have been reported in the United States and worldwide. They vary genetically for virulence and have been able to overcome previously resistant plant varieties (e.g., potatoes), and they also pose the threat of developing resistance to certain types of fungicides. P. infestans infects all aboveground parts of susceptible plants at any stage of plant development.
Disease management:
1. Select a tomato variety that reaches maturity quickly (i.e., early-bearing or short-season types). This will allow the grower to get the crop harvested as soon as possible. "Early-season" tomato varieties require about 55-67 days to reach maturity; whereas "mid-season" and "late-season" varieties require from about 68-78 days and about 79-85+ days, respectively.
2. Grow tomatoes in glasshouses or in spaces where there is humidity control and the plants are covered and protected from rainfall.
3. Ensure quick and vigorous tomato seedling growth though adequate and supplemental plant nutrition. Silicate-containing fertilizers may increase pest resistance,especially in the seedling stages.
4. Harvest early. If your tomatoes are nearly full size (yet green) and there is a big storm coming and you can use green tomatoes, you might as well harvest them.
5. Stake up tomato plants, especially indeterminate types. Keep tomato stems and branches away from the ground.
6. Intercrop tomato with non-susceptible host plants, preferably non-solanaceous plants.
7. Practice good crop sanitation; inspect the plants regularly for late blight disease symptoms and promptly remove diseased material from the plot or garden
8. Eliminate cull piles in the vicinity of tomato plantings.
9. Protect plants seedlings with fungicides that are registered in your area for this crop and disease.
10. Do not plant potatoes near tomatoes, or if potatoes are planted, use a blight-resistant variety.
For more information: contact Lancaster County Cooperative Extension,1383 Arcadia Road, Room 140,Lancaster, PA 17601-3184, Phone: 717-394-6851
All Right Reserved © 2010 plantdoctorapp.com