Die Belastung der Kartoffelknolle mit dem Erreger der Schwarzbeinigkeit und Knollennaßfäule,Erwinia carotovoravar.atroseptica(van Hall) Dye, und anderen Naßfäule verursachenden Bakterien unter industriemäßigen Produktionsbedingungen

Contamination of potatoes by Erwinia carotovora during grading

“…If most of the bacteria survived in storage, as observed when deep external wounds were incurred during grading. the risks of decay would be high (Scholey et at., 1968;Naumann et at., 1978). Also, if the bacteria were predominantly Fea, a high blackleg incidence could be anticipated in the following season (Boyd & Penna.…”

“…1980;McCarter-Zorner et ai, 1984) and it is more commonly isolated from the virus-tested stocks during their early years of multiplication in the field (Graham et at.. 1976;Perombelon et at., 1976), However, in later years the stocks are handled by mechanical methods because of the quantities involved, Eor example, the same grader may be used for both VTSCderived stocks and lower-grade seed stocks which may be contaminated by Fca. Eurthermore, Fea predominates in naturally rotted tubers in store (Perombelon, 1972;Naumann et al, 1978;Campos et at., 1982) because it is more pathogenic than Fee at the low temperatures of < 15 C which prevail in stores (Perombelon ct at., 1979), There-fore, Fca from the ubiquitous rotting tubers rather than Fee is more likely to spread within and between stocks during grading.…”

“…In store, mechanical grading has long been thought to cause spread of the bacteria because there was more soft rot (Scholey et al, 1968; * Present address: International Potato Center (CIP), PO Box 5969, Lima, Peru, Naumann et al, 1978) and blackleg (Boyd & Penna. 1967: Graham & Hardie, 1971Henriksen.…”