Loading in 2 Seconds...
Loading in 2 Seconds...
How does host genotype diversity affect the pathogen population?. Mixtures (blends) and multilines (mixtures of NILs) Mechanisms Dilution of inoculum Barrier effect Induced resistance. Technically… Mixture : different species fescue + bluegrass Blend : different varieties, same species
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
“Planting blends is one way to reduce the chances of picking the wrong variety for the conditions that develop.”– Jim Shroyer, Kansas State University agronomist
“Ted Wolf grows equal amounts of three different varieties, then plants them as a blend the following year.”
So far, nine rust R-genes identified, mostly from C. canephora and C. liberica
Figure 12. Susceptible Coffea arabica on the left; a resistant hybrid with C. canephora on the right.
Rust caused by the fungus Melampsora is the most serious disease in short rotation coppice (SRC) willow plantations for renewable energy. Willows (Salix) are grown as a major SRC crop for energy because of their yield potential and coppicing ability. In most willows, rust only infects expanded leaves (left picture). However, in some willows, such as Salix viminalis and S. caprea, rust also attacks stems and young leaves. When severe, rust defoliates susceptible plantings prematurely (right picture) and reduces yields by as much as 40%. Severe rust also predisposes plants to infections by secondary pathogens which may lead to death of the plants.
* Venturia inequalis causes apple scab
* Within-row mixtures: 7-21% reduction in incidence over 2 yrs, 35% reduction in severity in second yr, compared to monoculture of S cultivar
Chin and Wolfe (1984, Plant Pathol. 33:535-546) : planted pure stands and mixtures of 2 or 3 barley cultivars (H, W, M), each with a different gene for mildew resistance
Effects of wheat cultivar mixtures on epidemic progression of Septoria tritici blotch and pathogenicity of Mycosphaerella graminicola, 2002, Cowger and Mundt, Phytopathology 92:617-623.
Inconsistent performance of a mixture confronted with a splash-dispersed epidemic depending on environment