Avo 3.pdf
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I Main types of post harvest physiological deterioration of avocado Storage related damage CLOSE UP Chilling injury . Th s damage is caused by low temperatures generally lower than 3 ° C or by prolonged stor age . The symptoms may appear three days after packing during storage and more often when the fruits are removed from the cold room . Two forms of chilling injury are observed. The symptom of nterna chilling injury is a browning of he pulp starting at the base of he fruit and sometimes vascular browning in the same a ea. In Fuerte; this disorder takes the form of small dark spots in the pulp. The symptoms of external chilling injury are irregular black spots on the epiderm s . They may appear during storage and mo st frequent ly when th e fruits are removed from cold storage . 2 deficit and excessive C02. Too great a decrease in the 02 level (in particular to less than 1 ) can cause irregular brown spotting of he epidermis that can spread to the pulp. Too high a C02 level (over 10 ) can cause discoloration of he epiderm s and the development of unpleasant flavours, especially when the 02 level is low . Fungal infection in the field revealed during or after storage The control of fungal diseases requires effective orchard management and appropriate treatments before the harvest. All bruising of the fruits must be avoided at the post-harvest stage, they must be refrigerated rapidly and the cold chain maintained. Anthracnose. Th s is the most frequent disease du ring storage and is caused by infection of the fruit by Colle- totrichum gloeosporioides in the orchard and appears only du ing ripening. lt caus es serious necrosis. Ordinary small, scattered injuries develop into large circular brown spots on the epiderm s. The underlying pulp blackens and the rot reaches the stone. The rate of development of his rot depends on the transport and storage tem- perature and above all the state of maturity of he fruits. Stern end rot. This disease is also caused by infection by a fungus, Botryodip odia theobromae. Small pale brown spots appear initially in the stem zone. The rot spreads rapidly to the rest of the fruit. The pulp is then infected to the stone. Any injury in the epidermis favour s infection by the pathogen. Avocado Post harvest diseases caused y pathogenic fungi Pathogen · Diseases Alternaria spp Black rot Botryodiplodia theobromae Stern - end rot Botryosph aeria ribis Dithiorella gregaria) Stern - end rot Col/etotrichum gloeosporio ides Anthracnose : Black rot Fusarium spp Stern - end rot Penicillium expansum Blue mould Pesta/otiopsis perseae Brown spots Phomopsis perseae Brown rot Phytophthora citrico/a Small surface injuries Pseudocercospora purpurea Soft rot Rhizo pus stolonifer Corky patches on epidermis N o. 225 Septembe r 2014 Photos e Guy rehinler 1 0 1 N o. 225 Septe m be r 20 1 4 9
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