Pineapple - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 329

Pathological disorders
Thielaviopsis rot (black rot, water blister, soft rot or
water rot)
It is a universal fresh pineapple problem characterized by
a soft watery rot caused by the fungus Chalara paradoxa
(De Seynes) Sacc (Rohrbach, 1983). The severity is de-
pendent on the degree of bruising or wounding during har-
vesting and packing, the level of inoculum on the fruit,
and the storage temperature during transportation and mar-
keting (Rohrbach and Schmitt, 1994). Susceptibility varies
with the cultivar, with 'Red Spanish' types being more
resistant than 'Smooth Cayenne' types. Infection occurs
within 8-12 hours following harvest and enters through
the broken peduncle or other wounds. After penetration,
the pathogen grows rapidly into the flesh resulting, ini-
tially, in a dark yellow cone shaped soft rot. As the disease
develops, the flesh becomes watery and the juice exudes,
resulting in an empty shell showing only dark fibers inside
(Py et al., 1987). As the flesh softens, the skin above readily
breaks under slight pressure. The rot is commercially con-
trolled in fresh fruit by minimizing bruising of fruit during
harvest and handling, by refrigeration, and using posthar-
vest fungicides such as benzoic acid, salicylanilide, sodium
o-phenylphenate tetrahydrate, Benomyl, and Triadimefon
applied to the cut stem end or to the pineapple fruit surface
within 6-12 hours after harvest (Rohrbach and Phillips,
1990). The use of a hot water dip (54 ◦ C for 3 min) also re-
duces disease development in inoculated pineapples stored
at 10 ◦ C for 21 days followed by 48 hours at an ambient
temperature (28 ◦ ± 2 ◦ C). Fruit inoculated and heat treated
held at 28 ◦ ± 2 ◦ C for 6 days remained healthy (Wijerat-
nam et al., 2005). Bacterial and yeast antagonists can be
used as biological control agents against black rot (Reyes
et al., 2004).

tional status are the main factors. The low acid hybrids, now
being grown commercially, are more susceptible (Rohrbach
and Johnson, 2003).
The symptoms include light brown to black soft rot of
the central part of an individual fruitlet. FCR and associ-
ated symptoms are of major economic significance only as
epidemics, not at endemic levels. Infection frequently can
lead to misshapen fruit that is normally culled before pack-
ing and shipping. Control of FCR is achieved by spraying
Endosulfan at forcing and postforcing flowering (Rohrbach
and Phillips, 1990; Manicom et al., 2006; Petty et al., 2006)
to reduce mite population. Nonetheless, the US Environ-
mental Protection Agency has initiated action to end the
use of Endosulfan because it can pose unacceptable health
risks to farm workers and wildlife, and can persist in the
environment. In July 2010, EPA signed a Memorandum of
Agreement with the registrants of Endosulfan that will re-
sult in voluntary cancellation and phase out of all existing
Endosulfan uses in the United States. The last use date for
pineapple will be July 31, 2016 (US-EPA, 2010). Endosul-
fan has been banned in the European Union because of its
toxicity (ILRF, 2008).

Fusariosis
This is caused by the fungus Fusarium subglutinans. Infec-
tion probably occurs through open flowers, although major
levels of disease also occur from inoculations to the devel-
oping inflorescence (Ventura et al., 1981) and from injuries
caused by insects. The disease incidence varies according
to the time of harvest and growing season. The greater
the number of hours below 23 ◦ C during flowering and the
rainfall between flower induction and harvest, the greater
the disease incidence (de Matos and Cabral, 2006). As the
number of hours greater than 28 ◦ C increases during inflo-
rescence development, the incidence of fusariosis is rela-
tively lower. Fusariosis in Brazil is the most serious prob-
lem causing significant yield losses. While genotypes such
as 'Perola' and 'Smooth Cayenne' are susceptible, 'Per-
olera' and 'Primavera' are resistant (de Matos and Cabral,
2006). The mild fruit symptoms are similar to those of FCR,
which vary from light through medium to dark brown, ex-
tending partially to completely down the fruitlet core. In
contrast to fruit symptoms in FCR, fusariosis involves mul-
tiple fruitlets, with the infected area of the fruit surface
appearing off color initially and later becoming sunken,
with profuse pink sporulation and exudation of gum. Con-
trol of fusariosis is most effective by planting disease-free
seed material and by controlling insects (Laville, 1980) or
fungicides.

Fruitlet core rot (FCR), black spot, fruitlet brown rot,
and eye rot
This disease is caused by an infection by a pathogen or,
more commonly, a group of pathogens such as Penicillium
and Fusarium, round yeasts and bacteria. In addition, two
mites have also been reported to be associated with the
occurrence of FCR epidemics (Rohrbach and Apt, 1986).
The degree to which the symptoms develop appears to de-
pend on the time of infection, the pathogen or mixture of
pathogens present, the cultivar, and the environmental con-
ditions (Rohrbach and Schmitt, 1994). Marie et al. (2000)
concluded that FCR in Martinique is promoted by a com-
bination of factors that determine the sensitivity of fruit.
Climatic conditions before harvest, acid content, and nutri-