Scientists Find Way To Stop Peaches Brown Rot

Press, Volume C, Issue 29634, 3 October 1961, Page 12

Scientists Find Way To Stop Peaches Brown Rot

’"I’M Fress“ Special Service

AUC3CXAND, October 2. Hrown rot in peaches, one of toe major problems for the New Zealand canning industry, is steadily losing ground through scientific research. The rot, caused by a fungus, attacks the fruit as it ripens and can cause devastating losses in years when high temperatures combine with high humidities during the ripening period. Since New Zealand is now virtually self-supporting for its supplies of canned peaches —nearly 200,000 bushels were

processed last year—and will soon be looking for overseas markets, the problem is one to the Because of toe rot, growers often harvest their fruit before it is properly mature and while it is still resistant to toe fungus. This avoids rot but gives poorer peaches in toe can. A new ripening technique has been developed in Australia for cutting the losses' from brown rot and for ensuring foe production of highquality canned peaches. “We ran a series of trials at our research orchard in Havelock North last season, with very promising results,” said Mr W. A. Fletcher who is carrying out research on fruit and vegetable processing at the fruit research division of toe Department of Scientific and Industrial Research. Temperature Control The technique is based on the discovery toot foe brown rot fungus stops growing at a temperature of around M degrees, Fahrenheit, while the ripening process of the peaches continues aatufoctorilyat this temperature. idea is to harvest toe peaches slightly immature, before brown rot develop and to ripen foem in a store of M or S 5 If the quantity of fruit rip «™’d by this means is too much for immediate canning toe surplus can he immediately transferred to cool "forage at n degrees and held in good condition for two or three weeks.” During the last season trials SEL“SISI’£ O SS edged as one of the finest canning peaches in the world brown rot, even when they

were deliberately inoculated with the brown rot fungus. The heat-ripened fruit also developed a deeper and more attractive colour and a firmer flesh texture than fruit ripened at ordinary temperatures or tree-ripened fruit. They looked far more attractive in toe can or on a plate. The only problem was that the heat-ripened peaches developed a slightly unusual flavour. Taint From Paint “We don’t know yet whether this is due to the high temperature or, as we suspect, a taint derived from paint in the new ripening room,” said Mr Fletcher. “Further trials next season should test this point and see whether other varieties can be treated as effectively as Golden Queen. “More information is needed on this effect on flavour before we can recommend the heat-ripening as a commercial practice. But the major canneries in the country are very interested in the investigations and a few are contemplating carrying , out trials of their own next season. “In fact,” he said, “one Nelson firm has already made limited use of the technique, with apparently satisfactory results, although we have not yet been able to check samples of their treated