Excision and mechanical perturbation induces pithiness in
celery petioles, and the induction appears to
involve the plant hormones ABA and ethylene
(Pressman et al., 1984; Saltveit and Mangrich,
1996). Mechanical wounding (i.e. cutting) of
harvested celery also appears to exacerbate aerenchyma
formation (i.e. pithiness) during storage.
Pithiness can be minimized by selecting dense
petiole segments, by excluding ethylene from the
storage atmosphere, and by maintaining high
relative humidity and the recommended storage
temperature of 0 8C. The third deleterious change,
flaring of the cut ends, has not received much
attention, but it appears to be the result of cellular
expansion and rupturing of the parenchymatous
cortex and pith tissues.