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Susceptibility of tobacco blue mould ( Peronospora hyoscyami ) to metalaxyl
Author(s) -
JOHNSON G. I.,
SHEPHERD R. K.
Publication year - 1983
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.1744-7348.1983.tb02672.x
Subject(s) - metalaxyl , biology , inoculation , fungicide , horticulture , bioassay , solanaceae , botany , veterinary medicine , medicine , genetics , biochemistry , gene
SUMMARY The lethal dose (LC 50 ) of metalaxyl for a wild isolate of Peronospora hyoscyami f. sp. tabacina was determined using a bioassay. Infection levels were recorded using 5‐wk‐old tobacco seedlings that had been treated with foliar sprays of metalaxyl (Ridomil®) 24 h prior to inoculation. Plants were maintained in a controlled environment cabinet. LC 50 estimates determined by probit analysis of the data from three independent experiments ranged between 0–46 and 0–58 μg/ml. Pooling the results for all three experiments, probit analysis gave a slope of 8·733 (S.E. 0·805) with an LC 50 of 0·51 μg/ml (95% fiducial limits 0·45, 0·57). This determination will be useful as a guide to future monitoring of P. hyoscyami for resistance to metalaxyl.