Tomato late blight is a devastating disease of tomato and potato plants, caused by Phytophthora infestans. It can cause severe crop losses and was responsible for the Irish potato famine in the mid-1800s. The disease was first described in 1845 from potatoes and in 1847 from tomatoes in France It was later confirmed to be caused by the same organism, P.infestans, by de Bary in 1863. The disease spread to the U.S. in the 1840s, possibly through infected tomatoes imported from Mexico New and more aggressive strains of the pathogen emerged in the 1990s, posing a greater threat to tomato production worldwide.
- Type of Infestation: Disease
- Common Name: Late Blight
- Scientific Name: Phytophthora infestans
- Category of Plant Disease: Fungal disease
- Mode of Spread: Late blight is spread from infected transplants, Spores (through air/water)
- Most Affected Plant Part: Leaf, stem and fruit
- Most Affected States in India: Karnataka, West Bengal, Punjab, Uttar Pradesh ( Severity in Shimla district of Himachal Pradesh).
Environmental Factors Favorable for disease/pest development:
- Temperature: sporulation is optimal at 12–18 °C
- Relative Humidity: Highest sporulation is noticed at 85 – 90 % of relative humidity
Symptoms
- Initial Symptoms: Leaves are irregularly shaped, water-soaked lesions, often with a lighter halo or ring around them . Lesions expand rapidly and the entire leaf becomes necrotic.
- Severe Symptoms: Lesions become enlarged and leaves turn brown, shrivel and die. Late blight fungus can also attack tomato fruit in all the stages of development. Due to severe infection, disintegration of fruits leads to rotting of tissues.
Biological Control Measures for Late blight in Tomato
Prophylactic
| Prophylactic | Dosage/ Lit. of water | Number of sprays | Spray intervals | Method of application |
| Xymo BLT100 + Zymo Max Spread | 2 gm+0.10 ml | 1-2 | 3 -5 weeks | Foliar spray |
Curative
| Curative | Dosage/ Lit. of water | Number of treatment | Spray intervals | Method of application |
| Xymo BLT100 +Zymo Bioguard WLT6040 + Xymo Biologique | 2 gm+ 1 gm + 2 -3 gm | 2 -3 | 5 -7 days | Foliar spray |
Product Details
- Xymo BLT100 : This is available in powder form and it contains NON-GMO biologicals, lysing biocatalysts, stabilizers and bioenhancers. This is a broad spectrum bio-agents, which is recommended for Early blight and Late blight diseases of tomato.
- Xymo Max Spread: This is available in liquid form, which is helpful for uniform spreading of biopesticide on sprayed areas. This can be used for all crops. It breaks down the surface tension of water and increases the wetting and spreading of a spray solution.
- Zymo Bioguard WLT6040: The product is available in powder form and it contains NON-GMO Biologicals, Proteolytic Biocatalysts, Stabilizers, Bioenhancers. It increases Soil Microbial Activity, proliferates good soil aerobic microbes in the root zone with adequate nutrients & denies food for anaerobic pathogens and finally induces SAR.
For more details on the product, please visit page: ‘Diseases Management in Tomato Crop using UAL Organic Based Products’
