Anthracnose (fungal disease) Got watermelons? Keep an eye out for Anthracnose, a common fungus problem that can hit your crop. This disease, caused by a fungus called Colletotrichum spp., can make your watermelons look bad and cut down how many you get. It starts with little yellow wet spots on the leaves, mostly where the leaf veins are. These spots grow to about the size of a dime, turn a dark color, and can make the leaves look like they have tiny holes. This simple guide will help you spot and stop this watermelon woe!
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Type of Infestation: Disease
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Common Name: Anthracnose
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Scientific Name: Colletotrichum orbiculare
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Category of Plant Disease: Fungal Disease
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Mode of spread: Wind-driven rain, Irrigation water, Wind
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Affected parts of plant: Leaves, Fruit, Stem
Favorable factors for disease/Pest Development:
- Warm and humid weather: Temperatures between 70-85°F (21-29°C) and relative humidity above 90% create ideal conditions for spore germination, fungal growth, and disease spread.
- Frequent rain or overhead irrigation: Splashing rain and sprinkler systems disperse spores effectively, facilitating infection of new plant tissues.
- Poor air circulation: Densely planted crops or shaded areas with stagnant air allow moisture to linger, promoting fungal growth.
Symptoms:
Initial Symptoms:
- Tiny, circular, water-soaked lesions appear on the upper leaf surface, often near the veins.
- Elongated, oval-shaped lesions with brown or black centers develop on the stem.
- Immature fruit shows small, sunken black spots, often at the blossom end or near the ground where moisture gathers.
Severe Symptoms:
- Leaves become distorted, curl, and eventually fall off, leading to defoliation and reduced photosynthesis.
- infected stems may break easily.
- Fruit cracking and splitting can happen due to weakened tissues.
- Fruit quality and yield are significantly reduced.
Control measures for powdery mildew in Watermelon:
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Product
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Technical Name
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Dosage
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BOOST
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Propiconazole 25 % EC |
200-
300 ml per acre
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SAMARTHA
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Carbendazim 12 % + Mancozeb 63 % WP |
Use 300-400 grams per acre
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COC 50
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Copper oxychloride 50 % wp |
2gm/ltr
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