Sporulation of Pyrenopeziza brassicae (light leaf spot) on oilseed rape (Brassica napus) leaves inoculated with ascospores or conidia at different temperatures and wetness durations

摘要: In controlled environment experiments, sporulation of Pyrenopeziza brassicae was observed on leaves oilseed rape inoculated with ascospores or conidia at temperatures from 8 to 20°C all leaf wetness durations 6 72 h, except after 6 h duration 8°C. The shortest times inoculation first (l0), for both ascospore and conidial inoculum, were 11–12 days 16°C 48 h duration. For inoculum (48 h duration), the number produced per cm2 area seven eight less than 8, 12 16°C. Values Gompertz parameters c (maximum percentage sporulation), r rate increase in sporulation) l37 (days 37% maximum estimated by fitting equation data, linearly related values predicted inserting temperature treatment into existing equations. data fitted better logistic equations (which overestimated low temperatures). latent period derived 50% sporulation, l50) P. generally 16°C, increased as decreased Minimum numbers spores needed produce ≈25 ≈700 leaf,