average grain weight TO:0000589 TO_GIT:245 TO:0000509 plant_trait_ontology The average grain weight (TO:0000589) can be used to calculate the overall yield or produce from a field. A grain weight (TO:0000919) which is the average weight of a grain (caryopsis fruit; PO:0030104), including the caryopsis hull (PO:0006000). grain weight