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An assessment of fungicides for the control of wilt and die‐back caused by Phytophthora cinnamomi in container‐grown Chamaecyparis lawsoniana cv. Ellwoodii
Author(s) -
SMITH PAULINE M.
Publication year - 1980
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1980.tb03914.x
Subject(s) - fungicide , phytophthora cinnamomi , biology , inoculation , phytophthora palmivora , horticulture , phosphonate , compost , captan , tris , botany , phytophthora , agronomy , biochemistry
SUMMARY In fungitoxicity tests against Phytophthora cinnamomi on Chamaecyparis lawsoniana cv. Ellwoodii, a drench of furalaxyl (1000 mg a.i./l) applied to the compost in which 1‐yr‐old plants were growing, 1 wk before they were inoculated with 650 000 zoospores, controlled disease for at least 12 months. With an inoculum dose of 650 zoospores/plant, furalaxyl at 500 mg a.i./l controlled disease even when inoculation was 12 wk after fungicide treatment. Aluminium tris (ethyl phosphonate) (2000 mg a.i./l) applied as a drench 1 wk before inoculation with 650 000 zoospores/plant did not prevent root infection but delayed foliar symptoms for 9 months: the same treatment, using etridiazole (500 mg a.i./l) only slightly reduced disease incidence. When applied as a single drench 2 days before inoculation, prothiocarb (2000 mg a.i./l) and cuprammonium compounds (200 mg a.i./l) were much less effective than furalaxyl (1200 mg a.i./l), sodium ethyl phosphonate (1500 mg a.i./l), aluminium tris (ethyl phosphonate) (1500 mg a.i./l) or etridiazole (500 mg a.i./l). However, a drench of furalaxyl at 1000 mg a.i./l, aluminium tris (ethyl phosphonate) at 2000 mg a.i./l or etridiazole at 500 mg'a.i./l did not eradicate P. cinnamomi from compost containing infected root debris. Pre‐planting drenching of the compost was ineffective. All fungicide treatments were non‐phototoxic to 1‐yr‐old C. lawsoniana cv. Ellwoodii. These results are of special relevance to the control of P. cinnamomi on container‐grown woody ornamentals.