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Effect of temperature of production of Botrytis allii conidia on their pathogenicity to harvested white onion bulbs
Author(s) -
BERTOLINI P.,
TIAN S. P.
Publication year - 1997
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1046/j.1365-3059.1997.d01-24.x
Subject(s) - conidium , biology , incubation , inoculation , horticulture , spore , germination , incubation period , botany , botrytis , germ tube , botrytis cinerea , biochemistry
Botrytis allii colonies incubated at low temperatures have been reported to produce larger conidia that germinate faster and give rise to longer germ‐tubes than those grown at room temperature. The present study compared the effect of conidia produced at 20°C and at 0 and –2°C on their pathogenicity to artificially inoculated white onion bulbs, and the effect of conidial concentration (5×10 3 and 5×10 4 conidia/mL) on disease incidence, lesion area, incubation and latent period during storage at 20, 5 and 0°C. At all storage temperatures and periods tested conidia produced at −2°C caused a higher disease incidence and larger areas of rot than those produced at higher temperatures. When the conidial production temperature was raised to 20°C, the duration of incubation on the bulbs inoculated with 5×10 4 conidia/mL was more than doubled during storage at 0°C, tripled at 5°C, and took 50% longer at 20°C. The incubation period was not significantly affected by conidial concentration at 20°C, and only slightly at 5 and 0°C, but at low temperatures the latent period was longer because of the delay induced in sporulation. These data are consistent with the packers' opinion that cross‐infection of spring onions by long‐term refrigerated onions in grading lines caused earlier and heavier rotting.