Does anyone know the ideal crop for sustenance in the case of a nuclear/volcanic winter. Rhubarb springs to mind, grows well in cool climates and denying sunli

Does anyone know the ideal crop for sustenance in the case of a nuclear/volcanic winter. Rhubarb springs to mind, grows well in cool climates and denying sunlight produces a better crop. Any others? Edit: the book recommends stocking up on rice, beans & grains.