Premium
Effects of foliar sprays of daminozide on the incidence of potato common scab
Author(s) -
MCINTOSH A. H.,
BATEMAN G. L.
Publication year - 1979
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.1744-7348.1979.tb02955.x
Subject(s) - daminozide , biology , chlormequat , common scab , agronomy , horticulture , plant growth , bacteria , streptomyces , genetics
SUMMARY Single foliar sprays of the growth retardant daminozide (1.5–12 g/l) approximately halved the incidence of common scab, caused by soil‐borne Streptomyces scabies , on potted potato plants in the glasshouse. Two analogues of daminozide ( N‐ dimethylaminomaleamic and N ‐(dimethylamino)‐methylsuccinamic acids) also decreased scab, but others were inactive. Of 22 other unrelated growth regulators and translocated chemicals tested as foliar sprays, only gibberellic acid (0.1 g/l) decreased scab incidence, but many of the tubers were distorted. Chlormequat chloride and chlorphonium chloride, as root treatments, were inactive. In other experiments with daminozide, scab incidence was decreased after application to soil. In tests with two plants per pot, spraying one of each pair decreased its rate of stem extension, but did not affect the other, indicating that little or no daminozide passed into the soil from the roots of the sprayed plant. The decrease in scab brought about by foliar sprays was not altered by varying their timing during the period before symptom development (1 to 5 wk after potting). In agar plate tests, daminozide was only weakly toxic to S. scabies. It is concluded that daminozide probably decreased scab by altering the physiology of the plants, so that scab symptoms did not develop.