[Fantasy] [Low-Tech] Crops with extremely short cycle and low yield

[vicky_molokh]

Greetings, all!

What would be the unforeseen consequences of a fantasy setting having crops of extremely short lifecycles but also very low yields. E.g. a crop with 1/300 the yield, but capable of providing this yield (and dying) in just 24 hours. Or 1/50 the yield, but with a cycle of 7-10 days.

I am of course postulating this to be fantasy, not historical low-tech. Some more considerations are that (a) it's probably best to make the crop somewhat picky, so that it wouldn't be able to take over the rest of the ecosystem (or make other plants similarly vigorous) and (b) I'm not sure if I want a setting with seasons or without, so I'm wondering about both variants.

Thanks in advance!