Does PH affect tuber production?

[Boutique Tomatoes]

I'm barely getting any tubers and they're all on the small side. I planted short rows of a few different varieties this year and only got about twice what I planted. We had good moisture here, so it wasn't that they were too dry.

The soil has a decent amount of organic material, aged compost was put on the bed last year and they were mulched with some 2 year old straw bales that had been out in the elements. I've got high P and K, low/moderate nitrogen and decent minerals except for copper, but even after tilling in a lot of peat and adding sulfer and gypsum to the point my soil tests high on sulfer the PH is stuck at 7.2.

Could it just be the PH? I know they are supposed to like a much lower PH, but I've been reluctant to add aluminum sulfate.

[fortyonenorth]

I think the low pH advice for potato growing is aimed at preventing scab. I don't think that your 7.2 pH would affect yield that dramatically. Did you hill them up in a timely manner and so forth?

[Worth1]

Soil temperature plays a big roll in production.
Here is an excerpt from this link.
http://www.google.com/url?sa=t&sourc...Fqgclg&cad=rja

Potato is a cool-season vegetable that ranks with wheat and rice as one of the most important staple crops in the human diet around the world.
The white potato is referred to as the "Irish potato" because it is associated with the potato famine in Ireland in the 19th century.
Potatoes are not roots but specialized underground storage stems called "tubers." Maximal tuber formation occurs at soil temperatures between 60° and 70°F.
The tubers fail to form when the soil temperature reaches 80°F.
Potatoes withstand light frosts in the spring and can be grown throughout most of the country in the cooler part of the growing season, but they prefer the northern tier of states for maximal yield and quality.




Worth

[Boutique Tomatoes]

They were planted in trenches and the trenches filled in as the plants grew, then hilled on top of that. Plenty deep.

Worth may be on target with the soil temperature, but in the opposite direction. Everywhere else I've grown potatoes was at least 15+ degrees warmer on average.

This year the soil temperature was barely 60 in early June, in the trenches it may have been lower than that for quite some time.

[wmontanez]

If your soil has too much nitrogen favors folliage and not tuber formation. I had less potato yields this year compared to last year and did almost the same. Some people here in this forum reports low yields and I got at least 3 plants had NO potatoes at all but these are only one plant per variety so I don't know what was expected.