Management of disease resistance diversity of cultivars of a species in single fields: controlling epidemics.
The use of a diversity of resistance genes limits the development of polycyclic epidemics caused by airborne pathogens and reduces the risk that resistance be overcome by virulent races. Diversity can be easily achieved by growing mixtures of cultivars with different resistance genes and homogeneous agronomic traits. The mechanisms by which disease is reduced in cultivar mixtures include the loss of inoculum due to the presence of resistant plants between susceptible ones and resistance induced by avirulent pathogens. The complementary effects of individual mixture components reacting to disease pressure and to abiotic stresses result in greater yield stability compared with pure stands. The quality of products from mixtures is at least equal to that obtained with pure stands. This type of resistance management is applicable to both annual and perennial crops.
de Vallavieille-Pope
Claude
C
UMR INRA/INA-PG d'épidémiologie végétale et écologie des populations, BP 01, 78850 Thiverval-Grignon, France. claude.pope@grignon.inra.fr
D000383:Agriculture / Q000379:methods*; D010935:Plant Diseases / Q000235:genetics*