Stumbled across this link of a guy who holds 9 world records for largest of 9 different vegetables. His secret is compost tea. His exact recipe is a secret but it certainly looks like he's putting worm castings and kelp in it (as expected). They also said he's adding micronutrients so I'm thinking he's adding mulched up dynamic accumulators (though I didn't see any growing in his ridiculous garden).
https://www.youtube.com/watch?v=GaMN...layer_embedded
I think the long Alaskan sun is still part of the vegetable size but I think the tea is clearly the biggest part. I think he's also watering unprocessed sugars into the soil to feed the root zone microbes.
Food for thought.