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Experiments on the time of application of insecticide to decrease the spread of yellowing viruses of sugar beet, 1954‐66
Author(s) -
HULL R.,
HEATHCOTE G. D.
Publication year - 1967
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.1744-7348.1967.tb04501.x
Subject(s) - biology , sugar beet , sugar , agronomy , toxicology , horticulture , botany , microbiology and biotechnology , food science
SUMMARY Sprays of demeton‐methyl insecticide decreased the spread of yellowing viruses by aphids in sugar‐beet crops in England. Between 1957 and 1960, when yellows was prevalent, the incidence, assessed as ‘infected‐plant‐weeks’, was decreased by 36–41 % by one spray, depending on when it was applied, and by 55 % by two sprays, giving average yield increases of 1½ and 2 ton/acre of roots respectively. Between 1962 and 1966, when yellows spread less, a spray at the time when growers were advised to spray by the British Sugar Corporation decreased yellows incidence by 37 %, whereas sprays 2 weeks earlier or later decreased it by 24 % and 25 % respectively. Between 1958 and 1966 an annual average of 160000 of the country's 440000 acres of sugar beet has been sprayed, often to control Aphis fabae as well as to check the spread of yellows. A spray gives a profitable yield increase when yellows incidence in unsprayed plots is 20 % at the end of August.