Effect of downy mildew on productivity of sugar beets, and selection for resistance

SUMMARY The numbers of sugar‐beet plants infected with downy mildew in experimental crops increased slowly over a period of 8–15 weeks from late May. Few new infections appeared after the middle of August, although less than half the plants were then infected. Most infected plants recovered, and recovery was most rapid and complete in young plants, irrespective of the weather. Plants infected when young produced small roots, but their sugar content and juice purity at harvest was similar to those of uninfected plants. Plants first infected in late July and early August had the smallest sugar content and most juice impurities.

Section: Introductionmentioning

confidence: 99%

Field experiments on sugar‐beet downy mildew (Peronospora farinosa)

Byford

1967

“…As a high proportion of wild beet is diseased, it obviously provides a potential source of infection for sugar-beet crops. I did not study the spread of fungus diseases from the wild beet, but other workers have shown that such spread occurs and can cause considerable damage (Blencowe, 1955(Blencowe, , 1956(Blencowe, , 1957Hughes, 1959;Hull, 1949;Leach, 1945;MacKay, 1957).…”

Section: Discussionmentioning

confidence: 99%

Studies on the Importance of Wild Beet as a Source of Pathogens for the Sugar‐beet Crop

Gibbs¹

1960

“…Kuhn (1872) and Voglino (1899) described mycelium in the crowns of seed plants during the winter, and others have recently stressed the importance of the seed crop (Hochapfel, 1950;McKay, 1957;Mikheeva, 1958;Krexner, 1959;Pozhar, 1960). Other primary sources of the fungus are usually considered less important than seed crops, Leach (193 I ) obtained only few infected seedlings from commercial seed or seed harvested from infected plants.…”

Section: E a N S O F P E R E N N A T I O N O F T H E F U N G U Smentioning

confidence: 99%

“…After a mild winter, groundkeepers are the main source of infection in Sweden, and seed crops are only locally important (Bjorling & Mollerstrom, 1964). McKay (1957) and Blencowe (1956) reported Beta rnaritima as a source of downy mildew. We have seen infected groundkeepers in crops of cereals, peas, and potatoes, and on sites of the previous season's clamps, and occasionally they have started attacks of downy mildew in root crops.…”

Section: Fig I Sugar-beet Downy Mildew Infection End Of July 1965mentioning

confidence: 99%

Some observations on the economic importance of sugar‐beet downy mildew in England

Byford¹,

Hull²

1967

S U M M A R YSugar-beet downy mildew is most prevalent in England in the sugarbeet and mangold seed-growing area of South Lincolnshire and West Norfolk. The most widespread and severe recent outbreaks were in 1957, and in 1965 when 6412 acres were reported with more than 1 0 % infected plants. The fungus usually overwinters in sugar-beet and mangold seed crops, and in England other ways of overwintering are seldom important. Steckling beds are infected in the autumn, and the disease may increase rapidly in the seed crop in early spring. Summer-sown stecklings get more downy mildew than stecklings sown in spring under a cereal cover crop, and direct-drilled seed crops get more downy mildew than transplanted crops.