Showing papers on "Globodera rostochiensis published in 1977"
TL;DR: Following joint tests in the Netherlands, Germany and the United Kingdom a new scheme is proposed for naming pathotypes of potato cyst-nematodes, with several of the pathotypes recognised in the British, Dutch and German National Schemes are the same.
Abstract: Following joint tests in the Netherlands, Germany and the United Kingdom a new scheme is proposed for naming pathotypes of potato cyst-nematodes. Pathotypes of Globodera ( = Heterodera) rostochiensis and G. pallida are designated separately using a simple nomenclature Ro1 to Ron for G. rostochiensis and Pa1 to Pan for G. pallida. Currently seven clones are used to differentiate five pathotypes of G. rostochiensis and three of G. pallida. Several of the pathotypes recognised in the British, Dutch and German National Schemes are the same. Results of pathotyping tests may show considerable variation; adequate replication and standardisation of method are essential. With an internationally used scheme it is highly desirable that new pathotypes or differential clones are added only after testing at Institutes in several countries.
248 citations
TL;DR: The life history of an Entomophthora-like fungus, which kills females and causes the breakdown of the cuticle preventing cyst formation, is described and a method is described for estimating the number of diseased eggs in females and cysts.
Abstract: Most populations of the cereal cyst-nematode are parasitised by fungi killing females and eggs. The life history of an Entomophthora-like fungus, which kills females and causes the breakdown of the cuticle preventing cyst formation, is described. This fungus attacks other cyst-nematodes but not Globodera rostochiensis. A method is described for estimating the number of diseased eggs in females and cysts. Verticillium chlamydosporium was the most frequently observed egg parasite; it killed 50% of the eggs in females on barley roots in July in a field trial. Tarichium auxiliare and Cylindrocarpon destructans were found more frequently in soils where the nematode failed to multiply than in those where it increased but were not considered important as few females were infected. Similar numbers of new females were produced in soils where populations multiply or decline but in decline soils many failed to form cysts and few healthy eggs were produced.
128 citations
01 Jun 1977
TL;DR: Resistant cultivars available at present are effective against only some pathotypes and except where high crop values make use of nematicides economic, it is important to combine extended crop rotation with such cultivars.
Abstract: Potato cyst-nematode species are believed to have evolved in South America but now have a worldwide distribution and can be major and persistent pests except in the warmest soils. Both species contain pathotypes and their correct identification, although difficult, is important when planning control with resistant potatoes. Some closely related and very similar species are of minor economic importance. Resistant cultivars available at present are effective against only some pathotypes and except where high crop values make use of nematicides economic, it is important to combine extended crop rotation with such cultivars.
114 citations
TL;DR: The method has the advantage of not requiring light, and rearing canisters can be stacked in standard incubators, and its high reliability renders the method particularly suited to pathotype analysis.
Abstract: A method is described for the laboratory rearing of potato cyst nematode, Globodera rostochiensis (Wollenweber, 1923) Mulvey & Stone, 1976 and G. pallida (Stone, 1973) Mulvey & Stone, 1976. Potato root systems were grown in 500 ml of sand in closed, clear plastic canisters. The enclosed system inhibited foliage growth and stabilised moisture balance. Root systems were sustained by the seed tubers, but supplementary nutrient was added. Potato cyst nematode eggs were inoculated into the sand after root initiation. At optimum rearing temperatures of 15–20°c the life cycle was completed within 8–12 weeks. The cyst‐to‐cyst multiplication factor was 10–20‐fold. The method has the advantage of not requiring light, and rearing canisters can be stacked in standard incubators. Its high reliability renders the method particularly suited to pathotype analysis.
33 citations
TL;DR: In a study of heavily infested soils in England from 1972 to 1975, potato cyst nematodes were often as numerous in soil 20–40 cm deep as in soil 0–20 cm deep.
Abstract: SUMMARY
In a study of heavily infested soils in England from 1972 to 1975, potato cyst nematodes (Globodera rostochiensis (Woll.) Mulvey & Stone and G. pallida (Stone) Mulvey & Stone) were often as numerous in soil 20–40 cm deep as in soil 0–20 cm deep. Below 40 cm the nematodes were uncommon. Beet cyst nematode (Heterodera schachtii Schm.) was also as numerous or more numerous 20–40 or 40–60 cm deep as 0–20 cm deep. Pea cyst nematode (H. goettingiana Liebs.) was uncommon below a depth of about 20 cm.
22 citations
TL;DR: Small, sprouted tubers of potatoes grown for 6 wk and then pulled out of soil infested with potato cyst-nematode, Globodera rostochiensis Roi, increased the hatch of larvae, so that 100 days after planting the top 20 cm of the soil contained only one third of the original number of eggs.
Abstract: SUMMARY
Small, sprouted tubers of potatoes (cv. Pentland Crown) grown for 6 wk and then pulled out of soil infested with potato cyst-nematode, Globodera rostochiensis Roi, increased the hatch of larvae, so that 100 days after planting the top 20 cm of the soil contained only one third of the original number of eggs. The artificial hatching agent picrolonic acid alone at 8-6, 17*2 or 34-4 kg/ha rotavated into the soil did not increase hatch but 17*2 kg, incorporated in the soil after potatoes grown for 4 wk, did.
15 citations