Corn rust is a pathogen caused by fungus that can attack corn plants and cause wide spread damage to this staple crop. Much of the midwest farmlands are used to grow corn. What method will best mitigate the impact of corn rust on this important crop?
A)Corn should only be grown in rainy season so its not needed to integrate land
B)Corn should be grown in cold season
C) Cloning
D) Genetic variation so at least some plants would be resistent to corn rust