Preventing and Treating End Rot Disease in Kale Plants

Preventing End Rot Disease in Kale

Kale is a hardy green that can withstand cold temperatures, making it a popular vegetable to grow in fall and winter gardens. However, kale's cold tolerance does not protect it from all diseases. One disease that can affect kale during cool weather is end rot. Here is what you need to know about identifying, treating, and preventing end rot disease in kale.

What Causes End Rot in Kale?

End rot in kale is caused by a calcium deficiency in the plant. Calcium is an important micronutrient that helps build strong cell walls. Without adequate calcium, kale is vulnerable to infection from fungus and bacteria. Two common pathogens that cause end rot are Xanthomonas campestris and Pseudomonas spp. These organisms infect the leaves and cause water-soaked lesions that eventually turn dry and brown. As the lesions expand, they can kill entire leaves or damage large sections.

Identifying End Rot in Kale

The first sign of end rot is typically brown or black lesions on the margins of leaves. These lesions originate at the tip or edges of the leaf and slowly spread inwards. As the disease progresses, the lesions expand to form large dead patches. A clear dividing line often forms between healthy green tissue and the diseased brown sections. The affected leaves become dried out and papery in texture.

In some cases, end rot manifests first at the base of the kale plant. The stem near the soil line becomes discolored and slimy. The leaves further up the stem soon yellow and die back. Without intervention, the rotting stems can cause the entire plant to collapse.

Preventing End Rot in Kale

The best defense against end rot in kale is prevention. Follow these tips to keep your kale healthy and productive all season:

• Test soil pH - Kale prefers a soil pH between 6.0-7.5. Neutral to slightly acidic conditions have optimal calcium availability.
• Add calcium amendments - Mixing organic matter like bone meal or eggshells into soil before planting provides a calcium boost.
• Use calcium-rich fertilizer - Fertilizing kale with a complete fertilizer containing calcium prevents deficiencies.
• Check soil moisture - Kale needs consistent soil moisture. Allowing plants to dry out causes stress and calcium issues.
• Rotate crops - Don't plant kale in the same spot as last year's crops. Rotate to avoid disease.
• Remove weeds - Weeds compete with kale for water and nutrients. Keep them cleared for healthy plants.
• Scout regularly - Inspect leaves frequently and remove any diseased material immediately.

Treating End Rot in Kale

If end rot lesions do appear, prompt action can sometimes save plants. Start by removing and destroying any severely damaged leaves. For minor lesions, try spraying kale foliage with a calcium chloride or calcium nitrate solution. Apply weekly as a foliar feed to increase calcium intake. Be sure to test soil moisture and water plants if needed to avoid further stress.

As a last resort, fungicides containing chlorothalonil or copper may stop end rot from progressing. Always follow label instructions closely when applying any fungicide. Thorough coverage of both upper and lower leaf surfaces is necessary for best results.

Growing End Rot Resistant Kale Varieties

Plant breeders have developed several kale varieties with improved end rot resistance. Trying one of these types can help avoid problems:

• Dwarf Blue Curled Kale - Heavily curled, blue-green leaves. Stays compact.
• Redbor Kale - Frilly leaves with vivid red stems and veins.
• Winterbor Kale - Extremely cold hardy hybrid. Ruffled dark green leaves.
• White Russian Kale - Light green leaves with white stems. Slower to bolt.

With preventative care and prompt treatment if signs appear, your kale can thrive and avoid end rot disease. Be sure to harvest leaves regularly, as mature kale is less susceptible than young growth. Enjoy the bounty of your winter vegetable garden.

FAQs

What are the symptoms of end rot in kale?

The initial symptoms are water-soaked brown or black lesions on the leaf margins that expand and cause sections of leaves to die. Stems may also become discolored and rot at the base.

What causes end rot in kale?

End rot is caused by a calcium deficiency that allows fungal and bacterial pathogens to infect the leaves. Common culprits are Xanthomonas campestris and Pseudomonas spp.

How can I prevent end rot in my kale?

Test and amend soil pH, provide adequate calcium, use calcium-rich fertilizer, maintain even soil moisture, rotate crops yearly, remove weeds, and scout regularly for early signs.

What's the best way to treat end rot in kale?

Remove severely damaged leaves, apply calcium chloride or calcium nitrate as a foliar spray, improve soil moisture, and use copper/chlorothalonil fungicides if needed.

What kale varieties are end rot resistant?

Try growing Dwarf Blue Curled, Redbor, Winterbor, or White Russian kale. These varieties have better tolerance for the disease.