By Scout Nelson
Nebraska dry bean growers may see bacterial diseases rise this season after thunderstorms, hail, and higher temperatures. Growers need to watch for major diseases and learn how to identify them.
Four main bacterial diseases can damage Nebraska’s dry bean crops — common blight, halo blight, brown spot, and wilt. Each disease comes from a different type of bacteria. They all spread more easily when the moisture levels are high.
These diseases often appear when plants are wounded. Storms, hail, animals, or farm equipment can injure plants, making it easier for bacteria to enter. Bacteria need wounds or natural leaf openings to infect plants. Storms with strong winds and hail help spread bacteria by causing damage and moving infected plant parts between fields.
Bacteria also survive in leftover crop material. When the weather turns favorable, they can infect plants again. Each disease grows best at certain temperatures:
- Halo blight at less than 80°F
- Brown spot at less than 85°F
- Common blight and wilt at more than 85°F
Making the right diagnosis is key. “The efficacy of several control measures depends on the particular pathogen involved.” Correctly identifying the bacteria helps growers choose the best way to manage the disease.
Managing bacterial diseases is hard. Copper-based sprays give mixed results based on the weather and disease levels. Some success has been seen with hydrogen dioxide products.
Few bean types have tolerance to bacterial diseases, and full resistance is hard to find. Breeding programs are working to develop better disease-resistant beans.
Other helpful practices include:
- Using healthy seeds and avoiding nearby infected fields
- Tillage to break down infected plant material
- Avoiding plant damage from machinery or walking in wet fields
Growers should wait until plants are dry before entering fields to avoid spreading diseases further.
Photo Credit:nebraska-extenstion
Categories: Nebraska, Crops, Weather