Planting date/cultivar evaluation: Thirty-six sweet corn cultivars were evaluated for resistance to natural infection by common smut (Table 1). Plots were seeded to 30,800 plants/acre on May 16 and Jun 23 on the Hermiston Agricultural Research and Extension Center on Adkins fine sandy loam (pH 6.7, 0.9% organic matter). The...
Thirty-one sweet corn cultivars were evaluated for resistance to natural infection by common smut. To determine if there is High Plains virus resistance in commercial processing sweet corn cultivars, trials were conducted at the Hermiston Agricultural Research & Extension Center, and in two commercial sweet corn production fields near Moses...
Nearly complete sequences of RNA-CP and 3'-proximal RNA-TGB were determined for 43 samples of potato mop-top virus (PMTV) originating from potato tubers and field soil from Sweden, Denmark and the USA. The results showed limited diversity and no strict geographical grouping, suggesting only a few original introductions of PMTV from...
Describes the symptoms and damage caused by silver scurf, a fungal disease of potatoes. Includes color photos of symptoms. Discusses sources of inoculum and the disease life cycle. Suggests management practices (seed selection, crop rotation, seed treatments, management of die-down, sanitation, harvest, and storage) to minimize disease problems.
Two types of smut attack corn in the Pacific Northwest: common smut and head smut. This publication provides descriptions of symptoms and the disease cycle, and management strategies (which differ considerably between the two types). There is also significant new information, particularly related to common smut, regarding losses and control...
In Kentucky bluegrass (Poa pratensis), Claviceps purpurea, the causal agent of ergot, typically releases ascospores during the early-morning hours, between about midnight and 10:00 A.M., corresponding to time of flowering, when the unfertilized ovaries are most susceptible to infection. During aeromycology studies of C. purpurea in perennial ryegrass (Lolium perenne)...
Full Text:
County Extension Service, La Grande 97850;
Philip B. Hamm,Department of Botany and Plant Pathology
Ergot, caused by Claviceps purpurea, is a major disease of perennial ryegrass grown for seed in eastern Oregon. The objective of this research was to quantify and describe the spatial patterns of ergot severity in each of three 50-ha commercial fields of perennial ryegrass grown for seed in 2012 and...
In Kentucky bluegrass (Poa pratensis), Claviceps purpurea, the causal agent of ergot, typically releases ascospores during the early-morning hours, between about midnight and 10:00 A.M., corresponding to time of flowering, when the unfertilized ovaries are most susceptible to infection. During aeromycology studies of C. purpurea in perennial ryegrass (Lolium perenne)...