No abstract

2011. Variability among forecast models for (he apple sooty blotch/flyspeck disease complex. Plant Dis. 95:1179-1186.Several disease forecast models have been developed to guide treatment of the sooty blotch and flyspeck (SBFS) disease complex of apple. Generally, these empirical models are based on the accumulation of hours of leaf wetness (leaf wetness duration [LWD]) from a biofix at or near the phenological growth stage petal fall, when apple fiower petals senesce and drop. The models recommend timing of the initial fungicide application targeting SBFS. However, there are significant differences among SBFS forecast models in terms of biofix and the length of LWD thresholds. A comparison of models using a single input data set generated recommendations for the first SBFS fungicide application that differed by up to 5 weeks. In an attempt to improve consistency among models, potential sources for differences were examined. Leaf wetness (LW) is a particularly variable parameter among models, depending on whether on-site or remote weather data were used, the types of sensors and their placement for on-site monitors, and the models used to estimate LW remotely. When SBFS models are applied in the field, recommended treatment thresholds do not always match the method of data acquisition, leading to potential failures. Horticultural factors, such as tree size, canopy density, and cultivar, and orchard site factors such as the distance to potential inoculum sources can impact risk of SBFS and should also be considered in forecast models. The number of fungal species identified as contributors to the SBFS disease complex has expanded tremendously in recent years. A lack of understanding of key epidemiological factors for different fungi in the complex, and which fungi represent the most challenging management problems, are obvious issues in the development of improved SBFS models. If SBFS forecast models are to be adopted, researchers will need to address these issues.Sooty blotch and flyspeck (SBFS). a disease complex caused by numerous fungal species, impacts pome fruit production in humid regions worldwide (4,5.18,21.35.58,60). Although the disea.se is limited to waxy cuticles and does little damage to trees or fruit, the blemishes it causes can substantially decrease apple fruit quality and. therefore, value. In the eastern production regions of the United States, growers generally apply from 30 to 50% of a season's fungicides, usually from four to eight applications, to manage a set of summer diseases, including SBFS, black rot {Botryosphae-ria obtusa (Schwein.) Shoemaker), bitter rot {Glomerella cingutata (Stoneman) Spauld. & H. Schrenk), white rot or bot rot {B. dothidea (Moug.) Ces. & De Not.). Brooks fruit spot {Mycosphae-rella potni (Pass.) Lindau), and Alternaria blotch {Alternarla niali Roberts) ( 54). SBFS is the only consistent summer disease problem in northem regions such as New England but the other diseases become increasingly important going from north to south.Calendar-based management programs of ...

University of Maine researchers developed three commodity-specific grower focus groups (lowbush blueberry, apple, mixed vegetable) to discuss and survey 1) current access to weather information, and 2) interest in weather-based decision support tools. NOAA National Weather Service (30%) (n=47) was most commonly cited as a weather information source. Growers ranked greater forecast accuracy (31%) and localization (19%) (n=48) as highest priorities. Only 34% of growers reported current use of weather-based decision support tools, but 86% expressed interest in future use (n=134). The project team is using grower input to improve weather data access and decision-support tools for Maine farmers.