My sweet potato plants got very large leaves, size is almost the same as my hand size.
It's "White Triumph" variety. Afaik, sweet potato leaves are much smaller. Possible they have been overfertilized or it's normal for that variety?
I'm afraid they are overfertilized and I will get large leaves and no tubers. What do you think?
That's how they looks now:
Disclaimer: While I have a lot of experience with plants and fruiting vegetables, I don't have a lot of experience with sweet potatoes.
I wouldn't worry about it. They're too young for that kind of over-fertilization to have a big negative impact on the end result (unless it burns the plant or makes it susceptible to disease/pests), unless you keep doing it and it doesn't get enough of the other nutrients it needs beside nitrogen. At this stage, more plant vigor is a good thing.
Large leaves aren't generally a result of high nitrogen (lots of leaves are). Large leaves are more a result of plant maturity, and a good supply of phosphorus; it could also indicate that the soil is warm. In most vegetables, large leaves are a good thing.
If you know it has too much nitrogen, at some point, and you're still worried about it having too much nitrogen, adding some calcium/potassium should be helpful to balance that (but don't overdo it on the calcium, as that can change your pH, and I believe sweet potatoes wouldn't like that).
well, it seems they've been overfertilized in this case. Otherwise, I have no idea why I got so bad results. Bunch of large leaves, but tubers are very thin and long. There was fermented nettle fertilizer applied also and I guess it was a big mistake to do that. Usually, that kind of fertilization is fine, for most plants, but apparently, it should not be used for sweet potato.