I’m really dependent on tillage for all my potatoes so I can’t comment on that. I did do a trail (was with tuber grown) where a section of multiple rows didn’t get hilled. The yield was much lower. It’s like potatoes love getting hilled, seems like consistently have a growth spurt. This spring for my TPS seedlings I used a wheel hoe for hilling, and besides making more space for tubers, they get weeded, and also the extra benefit was that I covered all the small seedlings because I planted them a little close together. I suppose one could do the same with mulch, but not at my scale and my lack of enough time+ materials. Next year I want to reduce tillage more than I did last couple years in general, but I don’t see it happening with my potato patch.
For yield, my first year I got like 5x higher yields than in 2022 (yields in 2021 were up to 11 lbs for some plants!) , so I’ve thought about the reasons why quite a bit. They really need to grow fast in the spring and have good growth, because once they start flowering the growth slows way down, and they don’t have enough photosynthetic capacity to develop bigger tubers. One theory I have that is probably wrong for my season in 2022 is that it was so cloudy in the spring that the lack of sunlight triggered them to start flowering earlier than would have been preferable. It wasn’t a lack of water, or fertility, because the exact same thing happened in a couple rows that had more compost (and I irrigated regularly) I’m going to try to figure that part out in 2023! The seeds that I sent out were mostly berries from tubers that I had saved from and replanted from the best in 2021, so the potentially big yielding (in my climate anyway) and colorful selections.
This discussion I posted this morning talks about no till potatoes a bit. How to deal with slugs/crimping a cover crop - #2 by Landrace