Blight is a fungal disease that can affect tomatoes, potatoes and other members of the nightshade family. Early Blight is caused by the Alternaria solani fungus while late blight is caused by the Phytophthora infestans (p. infestans) fungus. Late Blight was responsible for the Irish Potato Famine between 1845 and 1849, destroying nearly 80 percent of Ireland’s potato crop. This devastating disease can infect and destroy your potatoes quickly. While good sanitation practices and the application of fungicides early in the growing season can help ward off blight in your potatoes, growing blight-resistant potato varieties may be more effective.
What is a blight-resistant potato?
Blight-resistant potatoes are potatoes known to resist the fungi responsible for blight, namely, Alternaria solani and p.infestans, thereby resisting the effects of blight. Some potato varieties appear to have a natural resistance to blight while others are being bred specifically to resist blight. Growing varieties known to be blight resistant is one of the best ways to avoid blight in your potatoes.
How do blight-resistant potatoes stop getting blight?
Blight-resistant potatoes are not susceptible to the Alternaria solani or p. infestans fungus. This means that even when the fungus is present in the soil, or nearby crops are infected with the fungus, the blight-resistant potato may be able to avoid infection in much the same way a person with a good immune system may avoid viral or bacterial infections.
Blight resistance does not mean the potatoes cannot get blight. It is still important to practice good gardening hygiene, like sterilizing knives and tools used for planting or harvesting potatoes, disposing of garden debris away from the garden, and keeping weeds at bay.
Are blight-resistant potatoes fully resistant to blight?
Blight-resistant potatoes are better able to resist or avoid blight, but they are not immune. The higher the potato rates as blight-resistant the higher the chances are that your potatoes will not be affected by blight. When weather conditions are favorable for blight, even blight-resistant varieties can succumb to late blight.
Are some varieties more blight-resistant than others?
Potatoes are typically listed as having high, moderate or low resistance to blight. Potato varieties listed with high resistance to blight are those most likely to remain free of blight, while those with low resistance are most likely to be infected if the Alternaria solani or p.infestans fungus is present in your garden. When reading plant descriptions online or in seed catalogs, look for a specific mention of blight resistance. If it is not mentioned, read the section on common diseases or pests with the variety you are considering to see if the variety is likely to be affected by blight.
Are there waxy and floury blight-resistant potatoes?
Some of the best waxy and floury blight-resistant potatoes include:
Waxy Blight Resistant Potatoes
- Molly Magic: This delightful purple potato has dense color all the way through. It can be eaten as new potatoes or left to mature for winter use. It is ideal for frying or roasting with other root vegetables.
- Nicola: Nicola is an early- to mid-season potato that produces large oblong potatoes. It is prized for potato salads. It also produces delicious new potatoes.
Floury Blight Resistant Potatoes
- Blue Danube: This is a mid to late-season potato prized as a baker, but is also good for frying or in salads. It has blue skin and white or cream-colored flesh. It keeps well for the winter in a cool, dry place.
- Cara: Cara is a white potato ideal for either mashed or baked potatoes. Cara is a long-season potato variety that matures in 140 to 154 days.
- Setanta: Setanta is a red-skinned potato that is best baked or fried. It matures in 126 to 140 days.
- Robinta: Robinta is a red-skinned potato with yellow flesh. It is used for boiling, mashing and baking. It is a late-season variety that stores well.
Which is the most popular blight-resistant potato variety?
Elba is considered the most blight-resistant variety of potato sold in the United States. It is a great table potato and can be cooked in a variety of dishes. It keeps well and maintains its unique and delicious flavor throughout the winter. Elba produces young “baby” or “new” potatoes as early as 65 days from planting and produces mature tubers in 90 days.
Top 5 blight-resistant potato varieties
- Nicola: Nicola is a yellow-fleshed potato with waxy flesh. It is prized for making potato salads, has a high yield, and stores well. It produces oval or oblong tubers.
- Cara: Cara is prized for its delicious mashed or baked potatoes. It produces large, round potatoes and stores well.
- Acoustic: Acoustic produces well-shaped oval or round tubers with white flesh. These potatoes are a good all-around table potato and are suitable for nearly any dish. It produces a high yield.
- Kennebec: Kennebec potatoes are a good all-purpose potato with white flesh. These potatoes mature in 80 days and are a good storage potato.
- Red Luna: This red-skinned potato has yellow flesh and is prized for making distinctive potato salads and fries. This early potato is ready in 68 days.
Blight can be a devastating disease that causes your potato tubers to liquefy or rot making them unsuitable for eating. While it isn’t always avoidable, you can lessen the chances your potatoes will get blight by practicing good gardening habits, like sterilizing your tools and keeping the garden clean, and by purchasing blight-resistant potato varieties from a reputable seller. Look for certified seed to ensure the seed you are buying is free of diseases.
While it might be tempting to save your own potatoes to use as seed potatoes the following year, doing so may introduce diseases (like blight) to your crop. I know that’s not a risk I am willing to take, what about you?