Most cut flower growers prefer a minimum of 5-7g tubers for commercial cut flower production, however some have achieved good success with 3-5g planting stock. The heavier the tuber, the more bells and taller, stronger stems.
Tubers heavier than 5g are often 'split' prior to planting, as the second growing point can often be much later and weaker than the first dominant point.
Cut tubers should treated with a fungicide immediately after cutting and planted straight away.
Typical fungicides include - Topsin (thiophanate-methyl), Risolex (tolclophos-methyl).