Black scurf is a fungal disease that attacks the roots and lower stems of potato plants. The disease is caused by the fungus Rhizoctonia solani, which often lays dormant in the soil waiting for favorable conditions to initiate an attack. The fungus can cause significant yield losses if left untreated, and therefore, it is important to take preventive measures and control the disease as early as possible.
Here are some ways to control black scurf in potato:
1. Crop rotation: Practicing crop rotation is a critical control measure for black scurf. The fungus R. solani can survive in the soil for several years, so planting potatoes in the same soil over consecutive years can build up the levels of the disease. Therefore, crop rotation can help to reduce the incidence and severity of the disease by breaking the disease cycle.
2. Soil sterilization: Soil sterilization is another control method that can kill the fungus in the soil. This process involves heating the soil to a temperature of around 85 degrees Celsius and maintaining it for about half an hour using chemicals or steam. Once the soil is sterile, you can plant potato seeds without worrying about black scurf.
3. Plant certified seed potatoes: It’s essential to use certified seed potatoes that are free from diseases, including black scurf. Certified seed potatoes have undergone various tests and inspections to ensure that they are disease-free. When you plant certified seed potatoes, you have a better chance of producing a healthy potato crop.
4. Fungicide treatment: Fungicide treatment is another option for controlling black scurf in potato. Several fungicides are available to control the disease. Applying a fungicide before planting the seed potatoes can protect them from the fungus. It’s important to follow the label instructions carefully and use the recommended amount of fungicide to avoid adverse effects.
5. Cultural practices: Cultural practices such as maintaining good soil fertility, avoiding waterlogging, and timely weed control can help in the control of black scurf. Proper soil fertility helps to maintain the vigor of the potato plant and, therefore, can withstand attack from the fungus. Waterlogging can increase the disease severity, and timely weed control helps to reduce humidity, which can promote the spread of the disease.
In conclusion, controlling black scurf in potato requires an integrated approach that involves a combination of cultural practices, crop rotation, soil sterilization, the use of certified seed potatoes, and fungicide treatment. With proper management, it’s possible to control the disease and produce a healthy potato crop.