This sunflower has been the subject of much speculation this summer as to how tall it is. We decided to find its biomass as well.
It was 3 metres 2ocm long.
We weighed it like this, having cleaned as much soil from the roots as possible.
Repeat readings for mass were 4.7kg, 4.6kg, 4.5kg and 4.4kg. The balance kept turning itself off. Not sure if there was some drift there but mean is 4.5kg if we round down.
Almost all of that is from carbon dioxide and water over the space of 4 months. It is a wet biomass because it has not been oven dried so contains liquid water. The flower head is about a quarter of the total mass.
