pcourterelle wrote in message ...
Hi all...for the past three years I've planted potatos and each year I had
lots of plant/greenery but very few spuds. Typically the greenery will be up
to 1 meter high and spread out over a 1 metre radius but yeild only one
giant spud and a three or four smaller spuds per plant. The soil is great
and I add compost and steer manure every spring. I mound up around each
plant. The spuds and rest of the veggie garden get a dose of liquid
fertilizer every two weeks. I've planted late maturing Burbank Russets. I am
in North America, Zone 4. I am considering trimming back the plants (as it
encroages other areas of the garden). Any advice you could provide would be
appreciated?

Thanks

ps Any good treatments to prevent potato scabs?

scab is prevented by lowering the pH. Potato yield is increased by
high phosphorous. So why not try to add rock phosphate next year,
which will do both?
and the way the plants have developed, it sounds like your garden (or
the way you fertilize) is very N-rich. So just the rock phosphate next
year, perhaps a bit of sulphur to further lower the pH, and nothing
else, and see how it goes.