**3.3 Pathological disorders**

It has been reported that degreening can aggravate the incidence of some fungi. However, the effect of treatment depends on process conditions. The effect of degreening on *Penicillium* spp. development depends on the temperature at which treatment takes place. When degreening is performed at 20–22°C (Mediterranean Region conditions), the *Penicillium* incidence rises because these temperatures are close to optimal for this fungus to develop [21]. Nevertheless, when treatment is carried out at high temperatures (28–29°C) as in Florida, the action of this fungus is inhibited [49]. In this case, treatment can even be seen as curing, which lowers the *Penicillium* incidence. It has also been reported that *Penicillium* incidence in degreened fruit is maturation-dependent, and more mature fruit generally show greater severity [50]. After degreening, traditionally the selection of the fruit affected by *Penicillium* has been manually done, but artificial vision and hyperspectral imaging methods have been recently developed for the early detection of affected fruit [51]. In addition to sorting and discarding affected fruit, the application of washing, sanitation, and specific antifungal treatments before degreening is highly recommended.

Degreening may enhance the anthracnose incidence because ethylene induces conidia germination, appressoria formation, and *Colletotrichum gloeosporioides* germination due to more accessible nutrients on fruit surfaces [52]. The development of this disease depends on ethylene concentration and treatment duration [53].

Another disease associated with degreening is stem-end rot (SER) caused by *Diplodia natalensis*. SER develops from latent infections by this fungus established in necrotic fruit button tissue. After harvest, this fungus reactivates and infects fruit through the natural openings that form between fruit and buttons during button separation upon abscission [54]. The SER incidence can be enhanced by degreening

treatment when the temperature comes close to 30°C and the ethylene concentration is high [37].
