Parasite interference does not affect the demonstration of vertical resistance, but it can totally destroy the evidence for high levels of horizontal resistance.
12.
Breeding for comprehensive horizontal resistance will require simultaneous quantitative improvements and will eventually control all the parasites that have epidemiological competence in a particular agro-ecosystem . ( 5 ).
13.
In breeding crop plants for horizontal resistance to their parasites, the disciplines of plant breeding, plant pathology, and crop entomology should be regarded as being amalgamated into a single discipline.
14.
This is because parasite interference declines as the area of a horizontally resistant host population increases, and it is least when the entire crop of a region has a high level of horizontal resistance in all of its cultivars.
