What are those hard black spots which appear on the skins of Yucon Gold potatoes, and are they harful if digested?
Potato Freckles
Sounds like you may have scab. If so you can peel the potatoes and they'll be just fine for eating.
Shoe
Thanks Shoe, my thoughts as well. Neighbor who received his seed potatoes from me was concerned and I told him we had the problem before and did as you suggested. Appreciate the feedback.
morgan
Did your neighbors potatoes show up with scab, too?
Just curious as there is a "common scab" that is due to soil pH and there is another type which is the result of a soil-living pathogen (from what my limited-use mind remembers).
Regardless I hope you got a nice potato harvest for winter use. Ahhh, potatoes...baked, country-fried, french fried, scalloped potatoes, boiled potatoes (in a basil/butter sauce). Well, don't get me started!
Shoe
Shoe, tell us more about the basil butter sauce! I just planted my fingerling potatoes (topsy-turvy planting schedule down here).
Shoe, did some net search on potato scab and came up with some interesting articles. Neighbor's potatoes, specifically the Yucon Gold were the ones affected. I went back and checked all of my Yucon Gold and found a couple which were affected. However, the spots are on the surface, and they are small, hard and black. Sounds like a variation to the more common brownish colored ones. I didn't care for the pH adjustment down to 5.2 as a method of treatment since nutrient uptake is better at 6.5. The main thing I did different than the neighbor was watering. I use soaker hoses and water each day as necessary, keeping the ground moist but not saturated. The recommended watering for potatoes is to water well during the tuber production, starting after the plant leaves appear and continue for 4 to 6 weeks. At six weeks my plants looked bigger and healthier than the neighbors, so apparently I got the watering part right.
Another thing I plan to do is to follow potatoes with corn the next season in the crop rotation patern. I had also heard that potatoes should not be heavily fertilized with organic matter such as fresh manure. I did check the saved potatoes for next season's crop to make sure there was no evidence of potato scab. Neither the reds or the russets ever seemed to have a problem. Probably best to go with treated seed potatoes for the Yucon Gold if problem persists.
Potato crops were excellent this year Shoe, and it doesn't appear that the scabs on any of the neighbor's potatoes are a problem from the edibility standpoint. Just peel the affected parts and dispose of the peelings rather than compost them.
Thanks again Shoe for the lead. It's been fascinating reeding.
Great! Sounds like you have a grip on things to me. And boy howdy taters sure do need some water, glad to hear you have those soakers. And yes, I agree on not using excessive amounts of manure for your taters rows. I tend to go more for potassium/phosphorus with a tad of nitrogen (cottonseed meal works great but is expensive for large plantings).
I tend to grow beans/peas after potatoes so they help put N back in the soil. Corn is such a heavy feeder I'm pretty much a cheapskate and will let the beans/peas help me with the fertilizer bill! Where I am I can sow early peas, harvest them and till them under then plant bush beans, harvest, then till, and still have plenty of time to set Brassica in those areas and they benefit from the N from the peas/beans and the clay soil I have benefits from all the leaf matter that was turned under helping to give it good tilth.
Cala, the basil and butter "sauce" (Alex's term) is simple cut up potatoes, boiled in lightly salted water, then drained and half a stick (or more?) of butter added to the hot potatoes along with some chopped basil. Stir it all around to coat the taters and serve. Easy, tasty, delicious but guard your plate cus people will swipe it if you aren't looking.
Shoe
Shoe, the basil/butter sauce sounds great for small steamed red potatoes. Can’t wait to try it!
I’ve been playing around with the rotational plan for next season as well. I fertilize in the fall with some well aged cow manure/hay, however I will try to avoid the area where I plan to plant potatoes.
I have toyed with the idea of planting some pole beans next to the corn after it is 6 to 12 inches tall. Since I will be following the potatoes with corn from now on I will probably concentrate on this area with a much of the composted manure as I can reasonably work in.
Thanks Shoe for the "recipe." Great way to use up some of the basil in the garden.
Mraider, why are you following your potatoes from now on with corn?
Calalily, according to the information I down loaded from the net, potatoes followed by a small grain crop such as alfalfa or corn can reduce the disease in subsequent potato crops. Other than starving out the infection, no really good explanation was given for this. Corn seemed the more reasonable choice to me for a subsequent rotational crop. The bacteria (Streptomyces scabies) responsible for potato scab can survive saprophytically in the soil for years, feeding on organic matter as well as other fleshy root vegetables such as beets, carrots, parsnips, radishes, trunips, etc. A three year rotational plan where none of the fleshy root crops are applied to the area where you plan to plant potatoes again is advisable. My garden plan is based on a four year rotational plan, so this should be sufficient.
Chemical treatment is not recommended for the family garden because of it's relative ineffectiveness, and most of us would prefer to avoid this measure if possible. I think besides crop rotation the watering was the second best measure I read about to control or prevent this disease. Watering at near saturation for 2 to 6 weeks during tuber production (starting with plant leaf immergence) was precisely what I did. I use a soaker hose on each row of potatoes, and a timer, watering four times a day for up to thirty minutes per watering. Each of four rows has a header system with four ball valves controlling the flow of water. I can increase or decrease the amout of water as necessary. The idea is to keep the rows constantly moist but not saturated. This worked fine for me since I found absolutely no evidence on my stored potatoes this year, and the neighbor who used some of my seed crop from last year had the problem this year. His system of watering was patterned after mine, however he did not use a timer, and watering was somewhat sporratic.
The third measure I use is NOT to heavily fertilize the area in the fall where I plan to plant potatoes next spring. Corn on the other hand gets an extra dose of composted cow manure.
Hope this helps Calalily.
morgan
We use corn in one row where I accidentally introduced nematodes.(trap crop, pull and burn) Corn is good for more than eating!
Calalily, how is it you accidently introduced nematodes? I understand there are several good species which can be added to the garden and have considered doing so. The trap, pull, burn sounds like a good idea to me...had not heard of that with corn. I have a rock wall at the back of my yard which I use for all garden scraps. Just lay them on top of each other and burn in the spring. Nothing gets turned back into the garden. This is contrary to one of my neighbors who tills back in everything including grass clippings. Although his soil is darker than mine he has way more problems.
Thanks again for the corn tip Calalily, will add that one to my bag of tricks. I have been collecting anecdodial tips from DG for several years now and I have hundreds of ideas which I incorporate into my plant files. Several weeks ago I was visiting kids in Colorado and went to several estate sales. One had a bunch of gardening books for a quarter. One of the books was called "1,001 Gardening Secrets...The Experts Never Tell You". I have been browsing this book for something new and have yet to discover anything new or of value. Can't compae at all to this place.
I bought tomato plants that had nematodes. I didn't know that's what the "bumps" were until I started losing the plants much later in the season and by pulling them up the roots were horrible with so many knots on them.
I've added beneficial nematodes, they don't kill the bad ones, but are great for soil dwelling pests.
Calalily, I recall seeing knots on the stems of tomato plants in the past, just didn't pay much attention to them. Gives me a new topic to research...Thanks for the input.
Whoa now, "knots on the stems of tomatoes" are not the same as knots on the roots of tomatoes. What you probably saw were the beginnings of roots, Mraider (a.k.a. "primordial roots" or "primordia").
Shoe
Ah, gotcha...thanks shoe.
Just trying to ease your worries....
Enjoy the day!
Best,
Shoe