'204 STATE HOETICULTURAL SOCIETY. 



sible, I will beg leave to mention a few complications that may confront 

 the cultivator in spraying for these diseases. If these fungi were all 

 animals, like wheat and oats, so that each fungus lived but one sum- 

 mer, ripened spores for next year's crop, and then died, it would be a 

 simpler matter to deal with them. Just as some flowering plants live 

 over winter and start in spring from underground root-stalks, as well 

 as from seeds, so do some of these fungi live over in the mycelium 

 stage, in the tissues of the host plant. Some have more than one kind 

 of spores and behave differently in their different stages. The apple 

 scab not only ripens spores to live over winter and attack healthy 

 plants, but it also passes the winter in the mycelium stage within the 

 tender twigs. Even though all its spores were killed the fungus would 

 thus survive and perpetuate itself the coming season, just as rasp- 

 berries sprout up from the ground. Spraying does not effect the 

 mycelium that is growing down in the tissues of a plant, hence the 

 scab fungus may spread from the twigs to the developing leaves and 

 fruit in the spring, even though spraying is carefully done. The black 

 rot of the grapes produces three kinds of spores and attacks both the 

 leaves and fruit of the vine. The apple-leaf rust is a bimorphic fungus. 

 It exists in the one stage as a rust on the apple, haw and kindred plants, 

 where it develops spores that germinate on the red cedar, producing 

 the well-known •' cedar apples." These cedar apples ripen spores that 

 germinate on the apple or haw leaves and there produce the rust, thus 

 completing the life round of the fungus. 



These cases are sufficient to show that we may sometimes apply a 

 remedy carefully and still miss the object in view. Persistent effort, 

 however, in the use of the fungicides recommended by the Experiment 

 Station will eventually eradicate most of the diseases. Experiments 

 at the Station at Columbia show that a two-pound solution is more 

 effective in preventing scab in an orchard that has been sprayed three 

 or four seasons than a six-pound solution is in a similar orchard that 

 has never been sprayed. Continued spraying, year after year, will 

 enable us to weaken our solutions until the labor of applying them 

 will be the principle part of the expense. 



Another phase of the work that I would emphasize as being most 

 important, is to spray all orchards and fruit grounds from the time the 

 plants are started. It is easy to keep orange rust from a blackberry 

 plantation by spraying before it ever gets in, but a slow and difficult 

 work to eradicate the disease, once it has become prevalent. In a 

 young orchard on the horticultural grounds the trees have been 

 sprayed for insects and fungi since they were started from the graft 

 and no traces of these diseases have appeared among them, though 



