How to Manage Damping Off in Cauliflowers and Cabbage
Damping off (caused by Pythium spp. and Rhizoctonia sp.) is a devastating soil-borne fungal disease that affects practically all vegetable crops, including tomato, brinjal, chilli, capsicum, cabbage, cauliflower, and others. Due to damping off in the soil, seeds that are present in the soil will be destroyed before or after germination.
Cauliflower is the most sophisticated vegetable of the Brassicas, considered more of a delicacy than a mainstay. It isn't as healthy or as prolific as its relative broccoli. It must have the exact growing conditions to grow otherwise it won’t thrive. It dislikes severe heat or cold, as well as being too wet or too dry.
Cauliflower is considerably more difficult to cultivate organically. It is subject to the slew of pests that attack cabbages and can be a real challenge for organic producers. However, if you give it precisely what it wants, it is typically not too difficult to be happy.
Symptoms of Damping off:
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Damping off of cabbage happens in two stages: pre-emergence and post-emergence.
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Seedlings are destroyed shortly before they reach the soil surface during the pre-emergence phase.
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Seedlings that emerge develop a lesion near where the tender stem contacts the soil surface, and the seedling collapses. The young radical and plumule are destroyed, and the seedlings decay completely.
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In some cases, the seedling may continue to grow even though the lesion girdles the stem.
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The infection of the immature, juvenile tissues of the collar at the ground level characterizes the post-emergence period.
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The lesion is quite sunken, and the stem resembles a wire, hence the name wirestem. The diseased tissues soften and become water drenched. The seedlings fall or topple over.
Etiology:
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It is caused by several soil-inhabiting fungi predominant: Pythium aphanidermatum, Pythium debaryanum, Phytophthora sp. and sometimes Rhizoctonia solani involved.
Favourable conditions:
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For a few days, high humidity, high soil moisture, cloudiness, and low temperatures below 24° C are excellent for disease infection and development.
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Crowded seedlings, heavy rainfall, poor drainage, and an abundance of soil solutes all impede plant development and exacerbate pathogenic damping-off.
Survival and propagation:
Primary spread: Soil, Seed, and Water
Secondary Spread: Conidia by rain splash or wind
Management of the disease:
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Deep ploughing in the summer kills the fungus.
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Preparation of elevated seed beds 15 cm high with drainage canals around them
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Before planting, cover the seed bed with farm waste materials such as rice husk, tobacco stubbles, waste grass, and palmyrah leaves, among others.
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To minimize seedling overcrowding, use a seed rate of 3 g/ha alone.
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Watering should be controlled to minimize excessive wetness on the bed surface.
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A Bordeaux combination of 0.4% (40 gm copper sulphate + 40 gm lime in 10 litres of water) or Copper oxychloride @ 0.2% (20 gm in 10 litres of water) is to be applied with a rose can to a 10 sq.m bed 2 weeks after planting.
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Three weeks after seeding, two to three spray drenchings of beds with 0.2% Metalaxyl are applied (20 g of Metalaxyl in 10 l of water).
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This must be performed every four days in regular weather and every two days in rainy and overcast weather. In the event of significant rain, the application must be resubmitted.
Use insecticides with caution!
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Wear protective clothing and safety equipment as directed on the label. After each usage, take a bath or shower.
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Even if you've used the pesticide previously, read the label. Follow the label's instructions exactly (and any other directions you have).
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When applying insecticides, exercise extreme caution. Understand your legal obligations as a pesticide applicator. You may be held accountable for pesticide-related injuries or damage.
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