Potatoes pests and diseases

Aphids

Aphids are small, soft-bodied insects that suck the sap from plants, causing them to wilt, yellow and eventually die. They are commonly found on the leaves and stems of potato plants.

Symptoms

The presence of aphids can be identified by the presence of sticky honeydew on the leaves, which is a residue left behind by the insects. Potato plants with aphids may also show stunted growth, curled leaves, and yellowing.

Control or Prevention

There are several ways to prevent or control aphids in your potato garden. One of the simplest ways is to spray the plants with a strong jet of water, which will dislodge the insects from the plant. You can also introduce natural predators such as ladybugs or lacewings to your garden to control the aphid population.

Another effective method is to use insecticidal soap, which is a natural and non-toxic way to kill aphids. You can make your own insecticidal soap by mixing 1 tablespoon of dish soap with 1 quart of water and spraying it onto the affected areas.

Regularly inspecting your potato plants for aphids and taking action early on can help prevent an infestation that can damage your entire crop.

Colorado Potato Beetle

The Colorado Potato Beetle is a major pest that affects potato plants in the United States. These beetles are native to North America, and they have spread throughout the country since the 1800s. They are known for their ability to quickly destroy potato crops, causing significant economic losses for farmers.

Symptoms

The Colorado Potato Beetle can be identified by its bright yellow color with black stripes on its wings. The adults are about 3/8 inches long, while the larvae are about 1/4 inches long and have a reddish-brown color. The beetles feed on the leaves of the potato plants, causing them to become skeletonized. This results in reduced photosynthesis and stunted growth of the plant.

Control or Prevention

There are several ways to control and prevent Colorado Potato Beetle infestations. One way is to use insecticides that are specifically formulated to kill these beetles. However, this method can be harmful to beneficial insects and can also lead to the development of pesticide-resistant populations.

Another effective method is to use crop rotation, which involves planting potatoes in a different location each year. This helps to reduce the number of overwintering beetles in the soil.

Handpicking can also be effective in controlling small infestations of Colorado Potato Beetles. Simply remove the beetles and larvae from the plants by hand and drop them into a bucket of soapy water.

In conclusion, Colorado Potato Beetles can be a major threat to potato crops, but with proper prevention and control methods, it is possible to minimize their impact on your garden.

Early Blight

Early blight is a common fungal disease that affects potatoes and other plants in the Solanaceae family. It is caused by the fungus Alternaria solani and is characterized by dark brown to black spots on the lower leaves of the plant. The disease can quickly spread to other parts of the plant, causing defoliation and reduced yield.

Symptoms of early blight include circular or irregular-shaped spots on the leaves, which may have a target-like appearance with concentric rings. The spots may also have a yellow halo around them. As the disease progresses, the leaves may turn yellow and eventually die.

To control or prevent early blight, it is important to maintain good garden hygiene. Remove any infected plant material and debris from the garden to reduce the spread of spores. Plant resistant potato varieties and rotate crops annually. Fungicides containing copper or chlorothalonil can be applied preventatively or at the first sign of infection.

Early blight can be devastating to potato crops, but with proper prevention and management techniques, it can be controlled. Regular monitoring and prompt action can help ensure a healthy and abundant harvest.

Late Blight

Late blight is a destructive fungal disease that affects potatoes, tomatoes, and other members of the nightshade family. The disease is caused by Phytophthora infestans, which thrives in cool and humid weather conditions. Late blight can cause significant damage to potato crops, resulting in lower yields and quality.

Symptoms of late blight include dark, water-soaked lesions on leaves that eventually turn brown and papery. White fungal growth can be seen on the undersides of the leaves and on the stems. Infected tubers develop dark, greasy-looking spots that can extend deep into the flesh.

Prevention is the key to controlling late blight. Start by planting disease-free seed potatoes and use a preventative fungicide before symptoms appear. Avoid overhead watering to prevent prolonged leaf wetness. Remove any infected plant debris from the garden and do not compost it. Crop rotation is also important; do not plant potatoes or tomatoes in the same location for at least three years.

If you notice late blight symptoms in your garden, remove infected plants immediately to prevent further spread of the disease. Dispose of infected plants carefully and thoroughly clean any tools used to remove them. Fungicides can be used to control late blight but should be applied at the first sign of symptoms for best results.

Wireworms

Wireworms are the larvae of click beetles and are considered to be one of the most damaging pests for potatoes. They can be up to an inch long and are thin and wiry in appearance. Wireworms can stay in the soil for up to four years, and during this time, they feed on the roots of the potato plants, leading to stunted growth and reduced yield.

The symptoms of wireworm infestation include small, round holes in the potatoes, particularly near the stem end. The potatoes may also have a hollowed-out appearance and may be misshapen. In severe cases, the entire crop can be destroyed.

To control wireworms, it is essential to practice crop rotation, which means not planting potatoes in the same spot for at least three years. Additionally, you can use insecticides specifically designed for wireworm control. These insecticides should be applied before planting or immediately after planting to kill the wireworms before they start feeding on the potato roots.

Prevention is key when it comes to wireworms. If you have had a wireworm infestation in the past, it is crucial to remove any potatoes left in the soil after harvest, as these can provide a breeding ground for wireworms. Also, be sure to remove any weeds or grass around the potato plants, as these can attract click beetles, which lay their eggs in the soil.

Blackleg

Blackleg is a common bacterial disease in potatoes caused by the bacteria Dickeya and Pectobacterium. It is a serious disease that can cause significant damage to potato crops.

Symptoms: Infected plants will show wilting, yellowing, and blackening of the stem just above the soil line. The leaves may also turn yellow and eventually die off. The tubers may develop dark, sunken lesions and can rot in storage.

Control or Prevention: To prevent blackleg, it is important to start with certified disease-free seed potatoes. Practice good crop rotation and avoid planting potatoes in the same location for at least three years. Remove and destroy any infected plants or tubers immediately. If you suspect blackleg, have your soil tested for the bacteria to confirm diagnosis. Control measures include using copper-based fungicides and antibiotics, but prevention is key.

Blackleg can cause significant yield losses if not controlled. By practicing good crop management techniques and using certified disease-free seed potatoes, you can prevent the spread of this bacterial disease and ensure a healthy potato crop.

Rhizoctonia

Rhizoctonia is a fungal disease that affects potatoes and other crops. It is characterized by brown or black lesions on the stems, stolons, and tubers of the plant. The disease can also cause the roots of the plant to rot, leading to stunted growth and reduced yields.

Symptoms of Rhizoctonia can first appear as dark, sunken areas on the stem near the soil line. As the disease progresses, these lesions may expand and turn black or brown. Infected tubers may also develop dark, sunken spots on their surface or be covered in a fuzzy grey mold.

To control or prevent Rhizoctonia, it is important to practice good crop rotation and avoid planting potatoes in the same area for at least two years. Fungicides can also be used to protect potato plants from the disease. It is important to note that Rhizoctonia can survive in soil and plant debris for several years, so it is essential to properly dispose of infected plants and soil.

In addition to these preventative measures, it is important to maintain proper soil moisture levels and avoid over-fertilization, as both of these factors can increase the likelihood of Rhizoctonia infection. By following these steps, gardeners can successfully prevent or manage Rhizoctonia in their potato crops.

Fusarium Wilt

Fusarium Wilt is a serious disease that affects potato plants. It is caused by a soil-borne fungus called Fusarium oxysporum. This fungus infects the roots of potato plants and restricts the flow of water and nutrients to the rest of the plant.

Symptoms

The symptoms of Fusarium Wilt in potato plants include yellowing and wilting of leaves, stunted growth, and reduced yield. The lower leaves of the plant are usually affected first, followed by the upper leaves. The stems of infected plants may also show brown discoloration. In severe cases, the entire plant may die.

Control or Prevention

Prevention is key when it comes to Fusarium Wilt. To prevent this disease, it is important to practice crop rotation and avoid planting potatoes in soil that has previously grown potatoes or other crops that are susceptible to Fusarium Wilt. Additionally, planting disease-resistant potato varieties can help prevent infection.

If your plants are already infected with Fusarium Wilt, there are a few steps you can take to control the disease. Remove infected plants immediately to prevent the fungus from spreading to healthy plants. Do not replant potatoes in the same soil for at least two years. Fungicides can also be used to control the disease, but they are most effective when used as a preventative measure before infection occurs.

In summary, Fusarium Wilt is a serious disease that can have devastating effects on potato plants. However, with proper prevention and control measures, it is possible to protect your crop from this destructive fungus.

Verticillium Wilt

Verticillium wilt is a fungal disease that affects many plants, including potatoes. The disease can be particularly devastating as it can cause significant yield losses in affected crops.

Symptoms

The symptoms of verticillium wilt in potatoes include stunted growth, yellowing and wilting of leaves, and a decline in overall plant health. The leaves may also develop brown or black streaks, and the stems may show signs of discoloration or even collapse. Infected potato plants may also produce smaller and misshapen tubers, which can significantly reduce yields.

Control and Prevention

Unfortunately, there is no cure for verticillium wilt in potatoes once a plant has become infected. However, there are several steps gardeners can take to prevent the disease from taking hold.

Firstly, gardeners should ensure that they only plant certified disease-free seed potatoes. They should also rotate their potato crops, ensuring that they do not grow potatoes in the same soil for several years in a row. Additionally, gardeners can use a variety of cultural practices such as using clean equipment, controlling weeds and managing irrigation to prevent the spread of the disease.

Finally, if a plant is showing signs of infection, it should be removed immediately to prevent further spread of the disease.

Scab

Scab is a common disease affecting potatoes. It is caused by a bacterium called Streptomyces scabies, which can survive in soil for several years. Scab causes raised, rough, corky patches on the surface of the potato skin. While scab doesn't usually affect the taste of the potato, it can make them less visually appealing and more difficult to peel.

Symptoms

The first symptoms of scab are small, circular, brown spots on the surface of the potato. As the disease progresses, these spots merge together to form rough, corky patches. In severe cases, scab can cover the entire surface of the potato.

Control and Prevention

Scab can be prevented by planting disease-free seed potatoes and avoiding planting potatoes in soil that has previously been infected with scab. Maintaining a soil pH between 5.2 and 5.5 can also help prevent scab. Crop rotation and avoiding over-fertilization with nitrogen can also help prevent scab.

If scab is already present in your garden, remove any infected potatoes and avoid planting potatoes in that area for several years. Fungicides can also be used to control scab, but they are not always effective and may have negative environmental impacts.

In summary, scab is a common disease affecting potatoes that can be prevented by planting disease-free seed potatoes and maintaining proper soil conditions. If scab is already present, removing infected potatoes and avoiding planting in that area can help control the disease.