Potato

1. Q: I used potatoes purchased at the grocery store as seed for planting and they rotted without sprouting. Why?

A: Many potatoes sold for fresh market consumption have been treated with chemicals to prevent sprouting in storage. These chemicals will also prevent sprouting after planting. Another possibility is that the potatoes that you purchased in the store were from this year's crop and had not been stored properly to break the rest period. Potatoes have a rest period which must be broken before the seed will sprout. Cool temperatures or extremely warm temperatures can break the rest period and allow potatoes to sprout. Next time plant certified seed that has been properly stored to induce sprouting.

2. Q: Can I save the small potatoes from my spring crop for planting in the fall in my garden?

A: Yes. This is commonly done because good seed potatoes are scarce in the fall. Sometimes the potatoes saved from the spring garden fail to sprout when planted in the fall because of a natural dormancy in newly harvested potatoes. Considerable controversy exists as how to handle these potatoes in order to break the dormancy and enable them to sprout when planted. One recommended procedure for breaking the dormancy includes harvesting the potatoes and placing them in a cool storage area, preferably in the range of 50 degrees F. until about 3 to 4 weeks before the anticipated fall planting date. At that time, remove the small potatoes and maintain them at normal environmental conditions until planting time. Maintaining the seed potatoes at a high humidity during this time by covering them with moist burlap bags or some similar material will also initiate sprouting. The small potatoes should be planted whole and not cut to prevent rotting.

3. Q: What size piece should seed potatoes be cut into?

A: Each seed piece should contain at least 2 to 3 "eyes". Research has shown that the best size seed piece weighs approximately 2 ounces.

4. Q: Sometimes my potatoes or the potatoes I see at supermarkets have a green color. Are these potatoes poisonous?

A: Potatoes that exhibit a green color contain a substance known as Solanine. This substance, if consumed in extremely large quantities can cause severe illness or death. This greening of potatoes is caused by exposure to light during the growing period or excessive exposure to artificial lights at grocery stores or supermarkets. In the garden, this is most common after heavy rains which uncover potatoes near the surface exposing them to sunlight.

5. Q: How do I know when my potatoes are ready for harvesting?

A: Potatoes are generally mature when the plant starts to turn yellow. Potatoes require 75 to 140 days from planting to maturity depending upon variety and the season in which they are grown. Immature potatoes will often skin and bruise easily. When digging potatoes, if the skin is not set and is easily removed, delay the harvest. Dig spring-planted potatoes before the soil becomes hot. Avoid harvesting the potatoes when the soil is wet to avoid potato diseases.

6. Q: I have some seed potatoes left from my spring garden. Would it be all right to eat them?

A: No. Potato tubers purchased for seed purposes definitely should not be eaten. Frequently, such tubers have been chemically treated. Like all treated seeds, seed potatoes should not be fed to humans or animals.

7. Q: After harvesting, how should I handle my potatoes to result in the longest storage time possible?

A: Dig potatoes when the soil is dry, being careful not to skin or bruise the tubers. Do not wash the potatoes. Place them in crates or some suitable container and store them in a dark area for about 10 days at a temperature of 60 degrees to 65 degrees F. with a relatively high humidity. After this curing period, keep the potatoes at 40 degrees to 45 degrees F. with the humidity near 85 percent and provide good air circulation.

8. Q: Can potatoes be left in the ground for storage?

A: Generally, no. Cool, humid conditions (38 degrees to 45 degrees F., and 85 percent relative humidity) are best for Irish potato storage. Leaving the potatoes in the ground with a heavy mulch to keep the soil cool will provide good temporary storage if the soil is not saturated and is free of wireworms and grubs. The potatoes would not stay dry enough in the soil to prevent second growth or sprouting. Several weeks at high temperatures can break the rest period in home-grown potatoes after which sprouts will develop on the tuber. All things considered, it is better to dig the potatoes and put them in a cool, damp area.

9. Q: Why do home-stored potatoes have a different flavor in the winter than in the summer?

A: Irish potatoes stored at temperatures below 55 degrees F. will taste sweeter and be stringier than those stored at warmer temperatures. At temperatures less than 55 degrees F., enzymes within the tuber convert starch into sugars causing the sweet taste and stringy consistency. Potatoes to be eaten should never be stored in the refrigerator. Sugars within the potatoes can be converted back into starch by storing the potatoes at temperatures above 65 degrees F. for a week or two prior to use. Some gardeners store potatoes in large lots in cooler temperatures to keep them from sprouting and keep a small quantity inside their house for immediate consumption.

10. Q: My potato plants produced small tomatoes this year. I planted them next to my tomatoes. Could they have crossed or have my potatoes mutated?

A: The fruit on the potato plant is actually the fruiting structure of the potato plant. The potato and tomato belong to the same botanical family and have similar growth characteristics. The potato flower looks very much like the tomato flower and is pollinated and fertilized identical to the tomato flower. The fruit will mature if the plant is left long enough. Your potato and tomato plants have not cross fertilized.

11. Q: What is a "Topato" which is advertised in gardening publications?

A: The Topato is a patented name used by a company to describe a plant which supposedly produces tomatoes above ground and potatoes beneath the ground. If a Topato is ordered, you will receive several potato seed pieces, a few tomato seed and usually a razor blade with instructions as to how the Topato should be planted. This generally consists of hollowing out the potato seed piece, placing several tomato seed in the hollowed out area and planting the result in your garden. If it germinates and grows, the result is both a tomato and a potato plant above and beneath the ground. It will not be a cross, one plant with the ability to produce tomatoes and potatoes, but will be two individual plants producing normally.

12. Q: The stems of my Irish potato plants are decayed. The plants weaken but do not die.

A: This is Rhizoctonia. It is a soilborne fungus that causes decay in stems and seed pieces. Approved seed-piece fungicides are the best of control. Follow the label instructions closely to get maximum control.

13. Q: After a rainfall, the plants in one area of my garden began to die rapidly. The stems were rotted. A dark discoloration is moving up the stem to the top of the plant, and the stem has a foul odor.

A: This is black leg of potatoes, one of the major bacterial potato problems. To avoid this, plant only in well- drained areas. Seed piece treatment will also help prevent the entry of bacteria and other organisms.

14. Q: When I dug my potatoes, they were covered by small, raised bumps.

A: These are root knot nematodes. They are a serious problem on potatoes.. Root knot is a species of nematode which causes galls or swellings on plant roots. It restricts the uptake of nutrients from the root system to the foliage, resulting in a yellow and stunted plant. Root knot lives in the soil and can survive on a number of weed and vegetable crops. It is best controlled by planting a solid stand (close enough for root systems to overlap) of marigolds three months before the first killing frost of fall and/or planting cereal rye (Elbon) for a winter cover crop. Cereal rye should be shred and tilled into the soil 30 days before planting a spring crop. Also, rotate where nematodes have become a major problem.

15. Q: After I dug my potatoes, I found that they were rough with deep scars.

A: This is potato scab, caused by a soilborne organism. To control this, maintain an acid soil around your potato plants. Maintain a uniform moisture level from the time the potato is formed until it is harvested. Seed-piece treatments have proven somewhat effective in preventing this problem.

16. Q: The lower foliage on my potato plants is beginning to turn yellow and is covered with brown spots.

A: This is early blight of potatoes and is similar to blight on tomatoes. Spray with chlorothalanoil-containing fungicide as soon as spots are observed and repeat at 7- to 14-day intervals for two to three sprays.

17. Q: The foliage of my potato plants is distorted, rolled and is not as thrifty as it should be.

A: Several viruses attack potatoes. The best prevention of potato viruses is to plant only certified seed pieces.

18. Q: When I dug my potatoes, I noticed small holes chewed in the potato. How do I prevent this?

A: Several soil-inhabiting insects such as wireworms and white grubs cause this type of damage. Use control measures for these pests before planting. Diazinon is effective on soil pests. Use as directed on the label.

19. Q: The leaves of my potatoes are disappearing fast. All I see on the plant is some pinkish worms.

A: These pinkish larvae are immature Colorado potato beetles. They can defoliate plants and should be controlled with Sevin, Thiodan, or methoxychlor. Use as directed on the label. In small plots, control by hand picking the larvae and destroying them.

20. Q: Is the potato the most popular vegetable in the world?

A: The potato is not the most popular but certainly the most important.

When Europe's 15th century explorers went looking for the riches of the East, they found the West. They also came upon a treasure that would ultimately prove to be more valuable than gold or spice: the potato. However, not until the middle of the 17th century, when Frederick William of Prussia planted them in his garden in Berlin, was any effort made to even grow potatoes in Europe. And it took even longer for the spud to find its place on the world's tables. That didn't happen until Frederick the Great began distributing them to the poor 100 years later.

It was a Frenchman named Parmentier who was the potato's biggest booster. Parmentier developed a taste for them while a prisoner in Germany, and upon his release, returned to France with a bag full of them that he used to cultivate more. His first crop was such a success that he presented a bouquet of creamy potato blossoms to his king. Louis XVI, who stuck a single flower in his buttonhole and gave the rest to his queen, Marie Antoinette. She, in turn, appeared at dinner with potato blossoms worked into an elaborate coiffure. That's all it took. France quickly adopted the potato, and soon the lowly brown tuber was bubbling away in pots all over the country. "France will thank you some day for having found bread for the poor," Louis XVI told Parmentier. And so it did, naming the now-classic French potato soup potage Parmentier.

21. Q: Can I save the small potatoes from my spring crop for planting in the fall in my garden?

A: Yes. This is commonly done because good seed potatoes are scarce in the fall in Texas. Sometimes the potatoes saved from the spring garden fail to sprout when planted in the fall because of a natural dormancy in newly harvested potatoes. Considerable controversy exists as how to handle these potatoes in order to break the dormancy and enable them to sprout when planted. One recommended procedure for breaking the dormancy includes harvesting the potatoes and placing them in a cool storage area, preferably in the range of 50 degrees F. until about August 1. At that time, remove the small potatoes and maintain them at normal environmental conditions until planting time. Maintaining the seed potatoes at a high humidity during this time by covering them with moist potting mix or compost material will also initiate sprouting. The small potatoes should be planted whole and not cut to prevent rotting.



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