INSECTS AND DISEASES 87 



A careful study of this disease in different por- 

 tions of the country seems to indicate that a long 

 rotation of crops, extending over five or six years, 

 will assist very greatly in keeping down the dis- 

 ease, as the germs are carried over from year to year 



Fig. 19. A rust-resistant Rocky Ford; note the fine netting. 



in the soil. In no case should watermelons follow 

 watermelons two years in succession. Then, too, 

 all diseased vines should be burned and all infected 

 fruit be disposed of in some place where the land 

 will not be used for growing melons. 



Disease-Resistant Plants. If we go into a melon 

 field where this disease is quite prevalent, we will 

 usually find here and there plants which are per- 



