Alternative fruit rot (postharvest disease)
Apple and pear fruits are affected by alternaria fruit rot, and in Japan and Korea the disease causes a great deal of pear damage. In most countries where apples and pears are grown, this type of caries is a common post-harvest disease.
Symptoms
Mostly on apple fruits with Alternaria fruit rot, round spots, brown to black, dry, firm and shallow usually formed around the ruptured and damaged skin or in the holes of the abdomen and ovaries. Occasionally, in the central area around the ovary, the black to gray mold grows and promotes decay in the meat. In pear fruit, decay starts from the place where the tail is cut.
The cause of the disease after harvest
Alternaria fruit rot is caused by Alternaria alternata. Another name for this fungus is A.tenuis Nees. The simple or branched conidiophores of this fungus are single or grouped, with one or more conidiic effects on them. The fungal conidia that are chained are golden- brown, smooth or warty.
Disease Cycle
A. alternata is a causative agent of Alternaria fruit rot, a weak saprophyte or pathogen that lives on dead and weakened tree tissues and attacks apple and pear fruits before or after harvest. The fungus attacks and infects fruits from weak or damaged tissue pathways as a result of mechanical or chemical damage, physiological aging and sunburn.
Control
– To Control and prevention of Alternaria fruit rot (postharvest disease), the fruits should be carefully removed during harvesting and packaging to prevent scarring and contamination.
– Transportation and storage box of fruit should be disinfected with chlorinated water or water vapor before use.
If the fruits are sprayed with benzimidazole group fungicides after harvesting to control other storage diseases, the incidence – of alternaria fruit rot disease will increase.