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Incidence of bacteria inhibitory to Erwinia amylovora from blossoms in New Zealand apple orchards
Author(s) -
KEARNS L. P.,
HALE C. N.
Publication year - 1995
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 - 10.1111/j.1365-3059.1995.tb02751.x
Subject(s) - erwinia , biology , bacteria , fire blight , incidence (geometry) , botany , microbiology and biotechnology , genetics , physics , optics
Populations of total bacteria and Erwinia herbicola were monitored on apple blossom in selected orchards at two different geographical regions in New Zealand (Canterbury and Hawke's Bay). In all four orchards surveyed E. herbicola populations remained negligible (less than 50cfu/blossom) throughout flowering, increasing rapidly at petal drop to reach levels of 1 × 10 3 cfu/blossom (Hawke's Bay) to 1 × 10 5 cfu/blossom (Canterbury). Total bacterial populations increased 100‐fold at petal drop in both locations. Pseudomonas populations were predominant in Canterbury throughout all flowering stages and in Hawkes Bay after early flowering. When screened for inhibitory activity to E. amylovora , 26% of all isolates from Canterbury showed some inhibition in vitro , but none of the isolates from Hawke's Bay showed inhibition of E. amylovora in vitro. Two Canterbury isolates with strong in vitro inhibitory activity also inhibited E. amylovora in immature pear fruit. One isolate was identified as E. herbicola and one isolate as Pseudomonas fluorescens.