Wireworm and Slug Damage to Ware Potatoes, 1954–56

Abstract

Each autumn since 1947, the Potato Marketing Board (Potato Division of the Ministry of Food before 1955) has carried out a survey of maincrop potato growers in order to obtain good, pre-harvest estimates of ware production. Fields surveyed were, in general, on the same farms each year, and the original farm sample was selected to be as representative as possible of potato crops in each region of Great Britain having regard to variety, soil type, and potato acreage. Growers of less than one acre of potatoes have not been fully represented in the annual samples since 1955 because the Marketing Board could only obtain information from registered producers and registration was not required of those who set less than one acre.Since 1952, advantage has been taken of the crop check-weighing scheme to obtain information on the incidence of Common Scab, and in the report on this work in 1952(Large and Honey, 1955 the standard yield sampling method is described. Latterly, the sampling rate has been varied such that 4 samples are taken on fields between 3 and 10 acres in size, whereas up to 8 are taken in fields of 30 acres or miore. In 1953, information was wanted on insect pest damage to the ware crop, and in 1954 and the two following years the crop check inspectors were asked to obtain supplementary information on wireworm and slug damage in each of the fields on the sample lists. In practice, nearly 3,000 ware crops, representing about 4 per cent of the national potato acreage, were inspected each season, and the sample tubers were graded as " sound " (those standing on a li-inch riddle which the trade would accept as ware), " wireworm damaged " (those with sufficient wireworm holing to render them unsaleable on the ware market), and " slug damaged ". In the rather rare cases where both types of damage occurred on the same tubers, grading was according to the pest responsible for the greater part of the damage. ACCURACY OF THE DAMAGE ESTIMATESThe accuracy of the crop check yield sampling method is known to be satisfactory. A standard error of rather less than ±0-2 tons per acre on an average yield of about 8-5 tons per acre was found by Dyke and Avis (1953) when a similar method was used on a sample of 1,000 fields in England and Wales. There remain, however, three sources of error in the detection of pest damage within the yield samples : first, tubers lifted from moist or wet ground are often covered with a thin layer of adherent soil which can obscure traces of insect damage ; second, the crop check survey work necessarily has to be carried out ten to thirty days before the crops are lifted and cannot therefore give a true picture of wireworm damage at the time of lifting ; and third, if, as Miles and Cohen (1937) have suggested, wireworm injury continues in clamped tubers, a further source of error is introduced in the assessment of national losses from crop check survey results.

Wireworm Damage and Insecticidal Treatment of the Ware Potato Crop in England and Wales

“…These results suggest that treatment was applied in a rather haphazard manner which bore little relation to the wireworm status of the individual fields. There is evidence, both from this country (Bevan and Bryden, 1956;Baker and Waines. 1957;MaskeU, 1958), and Canada (Burrage, 1960;Fox and Smeltzer, 1959), that soil treatments seldom eliminate damage, and are not very eflSdent at low wireworm population densities, in the season of application.…”

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A SUMMARY of results from a survey of pest damage to the ware potato crop over the years 1954-56 has already been published (Baker and Waines, 1957). The present article covers the seven-year period 1954-60, and is restricted to a consideration of wireworm damage in England and Wales in relation to the use of soil insecticides.

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The Ecology of Slugs in Potato Crops, with Special Reference to the Differential Susceptibility of Potato Cultivars to Slug Damage

“…Baker & Waines 1957) and Stephenson (1965) showed that severe damage is likely where crops are irrigated. Baker & Waines 1957) and Stephenson (1965) showed that severe damage is likely where crops are irrigated.…”

WIREWORM AND SLUG DAMAGE TO THE POTATO CROP IN SCOTLAND, 1954 to 1960

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A SUMMARY of wirewomi and slug damage to ware potato crops in Great Britain for the years 1954to 1956(Baker and Waines, 1957) and a paper on wireworm damage to the ware potato crop in England and Wales, 1954 to 1960 (Strickland, Bardner and Waines, 1962 have already been published. In this paper, damage to potato crops in Scotland by wireworms and other soil pests (mainly slugs) is considered for the years 1954 to 1960.

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