STATE POMOLOGICAL SOCIETY. 91 



dealing with parasites. Successful methods must be based upon a 

 general knowledge of fungi, and a familiarity with the life changes 

 of the one in hand. 



The following rules, based upon the general nature of fungi, may- 

 aid somewhat in checking, avoiding, or destroying these pests : 



1. If the parasite is established and lives within the host, reme- 

 dies are generally useless. 



2. If the parasite is external, spraying with a suitable fungicide 

 is often helpful, but sometimes the fungus will resist the action of 

 poisons as well, or better than the host. 



3. If a plant is hopelessly infested and liable to spread the dis- 

 ease to healthy plants, it should without delay be burned, root and 

 branch. 



4. Apply protective fungicides, to prevent the germination of 

 spores that fall upon plants. This is a preventive measure of great 

 promise. It would destroy summer spores, the greatest source of 

 infection, before the}^ have a chance to grow. Copper compounds 

 ^re coming largely into use. The}' destroy the spores which are so 

 rapidly formed during the summer months. 



5. Spray plants affected with a perennial fungus, during the 

 season of spore formation, to prevent the disease spreading to the 

 fruit and leaves and to other trees. 



6. When only portions of a plant are infested, use the knife at 

 once. Burn the diseased part. Do not throw it on the ground. 



7. Burn all refuse from crops in the fall, which may contain rest- 

 ing spores and perpetuate the disease over winter. Don't leave 

 rotten apples on the ground, or spread refuse from diseased apples 

 in the orchard. 



8. Destroy any wild plants or weeds, growing in the vicinit}' of 

 -crops, that harbor injurious fungi. 



9. Keep plants in health by proper fertilization. An impover- 

 ished or weak plant, like an animal lacking vigor, is an easy prey to 

 disease. 



10. Special fertilization, that is, the introduction into plants of 

 substancfts not harmful to their growth, but prejudicial to fungi. 

 This is problematical, though perhaps possible. 



The above principles are more or less applicable in the treatment 

 of fungi, but the life history of a particular fungus must be known 

 before a specific treatment can be adopted. Below we give a list of 

 a few common fungi that affect large and small fruits. 



In this paper only a few of the fungi of large fruits are consid- 

 ered, and these, for a want of time and space, have not received a 

 detailed consideration. 



