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Chemical Control of Carrot Fly ( Psila rosae (F.)) on Parsnip
Author(s) -
Hill D. S.
Publication year - 1973
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.1365-3059.1973.tb01788.x
Subject(s) - phorate , diazinon , biology , infestation , horticulture , acre , larva , agronomy , botany , toxicology , pesticide
SUMMARY During the past few years the recommended treatment for the control of carrot fly larvae on parsnip roots has been phorate granules applied ‘bow‐wave’ at drilling at 31b active ingredient/acre (3·36 kg/ha), followed by two foliar sprays of chlorfenvinphos each at 2 lb a.i./acre (2·24 kg/ha). This has been the standard recommendation for the control of carrot fly on carrots grown on peat soils. In a trial in 1972 this treatment gave useful control of a heavy carrot fly infestation on parsnips on a peat soil in eastern England. Protection lasted for approximately 30 weeks, after which the amount of damage increased sharply. Of the granular insecticides tested in the same trial as alternatives to phorate at drillng, chlorfenvinphos was reasonably eifective, but neither disulfoton nor diazinon gave adequate control. Two sprays of chlorfenvinphos applied later in the season to previously untreated parsnips were ineffective. Parsnips in untreated plots were heavily attacked by both first and second generation larvae; 37–40 per cent of the untreated plants were actually killed by the first generation larvae.