No abstract

Botrytis bunch rot (botrytis) can reduce grape yield and wine quality Standardised assessment methods are needed to allow greater precision in wine making and to allow the use of disease management decision support models in grape production This study developed a botrytis disease assessment key to assist the accuracy of visual disease assessment Associated computer training software designed to improve the accuracy of disease assessments was also developed and tested The mean absolute error in estimates of percentage botrytis severity was significantly (P

Therapeutic study-case series with no comparison group, Level IV.

Botrytis bunch rot (BBR), caused by Botrytis cinerea, results in serious losses to wine-grape production in some seasons during the preharvest period. In order to predict seasons that are at risk from BBR, datasets consisting of 25 disease, weather and vine phenology variables were aggregated from 101 SiteYears across seven regions and nine growing seasons. Automated analyses were used to compare a range of statistical methods for their ability to predict BBR epidemics, including the Kruskal-Wallis test, logistic regression, receiver operating characteristic analysis, and skill-scores. Variables based on relative humidity and surface-wetness duration were significant and consistent predictors of BBR epidemics across the range of analyses applied. Variables integrating temperature and wetness duration, including the Bacchus and Broome models, also demonstrated high predictive ability; however, they did not outperform their constituent components in all analyses. Automation of data analyses was an effective way to compare a wide range of statistical methods and a large number of variables with minimal user input, following initial code development. Significant time was needed to check input data and software code, but a greater return on investment would occur should the analytical process be applied to new datasets, including those from other pathosystems.