In June 2009, wilted hop bines were observed in a yard in Marion County, OR. The wilt was associated with a stem rot that occurred ∽1 m from the ground near the point where bines are tied together for horticultural purposes. Samples of affected stems were submitted to the Oregon...
Hop (Humulus lupulus L.) production recently has expanded across the United States to include areas of the country that have not previously grown hop commercially. In June 2015, a grower in western North Carolina detected powdery mildew in a small (<0.5-ha) yard during routine scouting. Characteristic signs of powdery mildew...
In August 2012, wilted hop bines were observed in a yard near Seneca Castle, New York, affecting 10 to 20% of the plants. Affected bines had a dark stem discoloration and wilted leaves that remained attached after bines were killed. Dark brown to black, erumpent pycnidia were aggregated in the...
Many plant disease epidemic models, and the disease management decision aids developed from them, are created based on temperature or other weather conditions measured in or above the crop canopy at intervals of 15 or 30 min. Disease management decision aids, however, commonly are implemented based on hourly weather measurements...
The binary power law (BPL) has been successfully used to characterize heterogeneity (overdispersion or small-scale aggregation) of disease incidence for many plant pathosystems. With the BPL, the log of the observed variance is a linear function of the log of the theoretical variance for a binomial distribution over the range...