The tolerance of grain amaranth (Amaranthus cruentus L.) to defoliation during vegetative growth is compromised during flowering

Tolerance to defoliation in Amaranthus cruentus changes during development and across warm season SS or cold season AW. As the plant builds carbohydrate reserves in stem and roots, it becomes more tolerant and maintains grain yield despite leaf damage. Tolerance is lowest if defoliation occurs at flowering, probably because carbohydrates are remobilized for new vegetative growth instead of being used for seed filling.