Comparison of monitoring- and weather-based risk indicators of botrytis leaf blight of onion and determination of action thresholds

Carisse, Odile; McRoberts, Neil; Brodeur, Luc

doi:10.1080/07060660809507542

Cited by 18 publications

(32 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent reports on evaluations of these management systems undertaken in the Netherlands, France and Canada indicate that the estimation of infection is the weakest part of these systems (De Visser, 1996; Huchette et al. , 2005; Carisse et al. , 2008a).…”

Section: Discussionmentioning

confidence: 99%

“…Most of them are protectants and hence should be applied before inoculum deposition on onion leaves. To circumvent this problem, the risk indicators used by the scouting network was expanded to include B. squamosa airborne inoculum monitoring (Carisse et al. , 2008a,b; Van der Heyden et al.…”

Section: Discussionmentioning

confidence: 99%

“…In that study, BLB risk indicators based on field monitoring of lesion density or airborne conidial concentrations were found to be the most reliable. Among the weather‐based indicators, those predicting the risk of BLB based on sporulation potential were more reliable than those based on infection potential (Carisse et al. , 2008a).…”

Section: Introductionmentioning

confidence: 99%

“…When BLB is at or above the upper threshold of 5 and 10 lesions on the youngest and oldest green leaves, respectively, the use of translaminar fungicides is recommended. This approach has proven efficient for managing BLB (Carisse et al. , 2008a; Van der Heyden et al.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, the accuracy of these BLB predictors was examined (Carisse et al, 2008a). In that study, BLB risk indicators based on field monitoring of lesion density or airborne conidial concentrations were found to be the most reliable.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A new risk indicator for botrytis leaf blight of onion caused by Botrytis squamosa based on infection efficiency of airborne inoculum

Carisse¹,

Levasseur²,

Heyden³

2012

Plant Pathology

View full text Add to dashboard Cite

Botrytis leaf blight (BLB) caused by Botrytis squamosa is a major leaf disease of onion. Various forecasting systems have been developed to help growers manage the disease. To improve forecasting reliability, the influence of temperature and wetness duration on B. squamosa infection was quantified by inoculating onion leaves with a conidial suspension and incubating them under various combinations of temperature (10-30°C) and leaf wetness duration (0-84 h). Infection was measured as the number of lesions per cm 2 of leaf and converted to the proportion of maximum infection (PMI). Regardless of leaf wetness duration, only a few lesions developed at 30°C and the number of lesions increased as the temperature rose from 10 to 20°C but decreased at 25°C. Between 10 and 25°C the number of lesions per cm 2 of leaf area increased gradually with increasing leaf wetness duration from 12 to 72 h. Relative infection was modelled as a function of both temperature and wetness duration using a modified version of the Weibull equation, which provided a precise description of the response of B. squamosa (R 2 = 0AE88). To facilitate field validation, receiving operating characteristic curve analysis was performed to determine the accuracy of various sets of criteria for establishing the length of an infection event based on field weather data. The total number of leaf wetness and RH >90% hours over a 72 h period was the best criterion, regardless of the wetness interruption pattern (sensitivity = 90AE91, specificity = 84AE62, area under the receiving operating curve = 0AE878). The model describing the relationship of PMI to temperature and leaf wetness duration, and field observations on airborne conidium concentration (ACC) were used to calculate the risk of infection (RI BLB ) as RI BLB = PMI · ACC. In 2009 and 2010, this risk index was compared to the observed rate of BLB progress (Rate BLB+5 days ) during the following 5 days. There was a linear relationship between RI BLB and Rate BLB+5 days indicating that this new risk indicator was reliable for predicting the risk of BLB development. These findings will help to improve the timing of fungicide applications for BLB management.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations