The Development of Eyespot on Seedling Leaf Sheaths in Winter Wheat and Winter Barley Crops Inoculated with W‐type or R‐type Isolates of Pseudocercosporella herpotrichoides

Abstract

In 1986???88 the development of eyespot lesions in winter wheat or winter barley differed plots inoculated with W-type isolates of Pseudocercosporella herpotrichoides and plots inoculated with R-type isolates. In the spring of 1986, after a cold winter, the incidence (%shoots infected) and severity (number of leaf sheaths penetrated) of eyespot lesions in wheat before GS 30/31 were greater in plots inoculated with R-type isolates than in those inoculated with W-type isolates. In 1987, after amild winter, eyespot incidence and severity in both wheat and barley were initially greater in W-type plots than in R-type plots. However, by GS 30/31 or 1987. In 1988, when the crop was October-sown, eyespot incidence and severity were greater in W-type than in R-type plots at GS 30/31. Differences in eyespot incidence and severity between W-type and R-type plots were smaller in barley than in wheat. Both the incidence and severity of eyespot were greater in early-sown than in late-sown plots. Seed rate, had little effect on the rate of lesion development in 1987, but in 1988 the rate of penetration was less at the low seed rate for both wheat and barley

Development ofOculimacula yallundaeandO. acuformis(eyespot) on leaf sheaths of winter wheat in the UK in relation to thermal time

“…The field experiments from 1985/86, 1986/87 and 1987/88 have been described previously, and the data analysed using chronological time (Goulds & Fitt, 1990a, 1990b, 1991). The experiments were arranged in two randomized blocks of nine plots (10 × 3 m) in 1985/86, or 12 plots (8·5 × 32 m) in 1986/87 and 1987/88.…”

“…The experiments were arranged in two randomized blocks of nine plots (10 × 3 m) in 1985/86, or 12 plots (8·5 × 32 m) in 1986/87 and 1987/88. Some details of these experiments are given in Table 1; full details are given by Goulds & Fitt (1990a, 1990b, 1991). Only data from plots of winter wheat (cv.…”

“… a As recorded in the Electronic Rothamsted Archive (ERA). Full details of experiments are described by Goulds & Fitt (1990a, 1990b, 1991). Only data from plots of winter wheat cv.…”

“…Most of the isolates used for inoculation came from Rothamsted (Goulds & Fitt, 1990a). In 1985/86 and 1986/87, the inoculum was a mixture of seven MBC‐sensitive isolates of OY or six MBC‐sensitive isolates of OA.…”

“…Thermal time (accumulated °C days) provides a more appropriate scale than a scale based on days from sowing, and has previously proved helpful in describing the progress of foliar disease of cereals (Beresford & Royle, 1988; Lovell et al ., 2004a). However, only days after sowing has previously been used as a measure to compare progress in stem‐base tissues of eyespot caused by OY and OA (Goulds & Fitt, 1990a; Poupard et al ., 1994).…”