Authors
Stephen S.
Strong
,
Former Graduate Student
,
Bridget K.
Behe
,
Associate Professor
, and
C. Fred
Deneke
,
Former Assistant Professor, Department of Horticulture
;
Kira L.
Bowen
,
Associate Professor, Department of Plant Pathology
; and
Gary J.
Keever
,
Professor, Department of Horticulture, Alabama Agricultural Experiment Station, Auburn University, Auburn 36849
ABSTRACT
Phytophthora parasitica was transmitted within 6 weeks from vinca (Catharanthus roseus) plants growing in infested potting mix, on the drain end of ebb-and-flow benches, to plants in noninfested potting mix. Transmission of Phytophthora was very low when potting mix was not pasteurized. When potting mix was steam pasteurized, infection of plants, disease incidence, and severity increased with time and decreased with distance from plants in infested pots. The cultivar Pretty in Pink was more susceptible to infection by P. parasitica than cv. Peppermint Cooler, allowing more rapid and severe disease development as well as pathogen dissemination and transmission. Pot spacing did not significantly affect transmission of P. parasitica on an ebb-and-flow bench.
