SPRAYING EXPERIMENTS. 55 



orange-yellow color (fig. 6, No. 4). About this time spores are 

 carried by the wind to apple trees, where in turn they produce 

 the summer stage of the rust. Spores from the summer 

 stage on the apple infect the cedar trees again during late 

 summer and autumn. 



RESISTANCE TO RUST AND SCAB. 



Varieties of apples differ widely in their susceptibility to rust 

 and scab. While a considerable number of our common vari- 

 eties of apples are not very seriously injured by scab, few of them 

 are perfectly free from its attacks. Varieties like Ben Davis 

 are commonly regarded as so resistant to scab that it does not 

 pay to spray them. They are nevertheless, far from being per- 

 fectly free from scab. From the behavior of young trees in the 

 Experiment Station orchards, Oldenburg, Whitney, Wealthy, 

 Salome, and Patten Greening might be said to be almost perfectly 

 free from scab. The writer has had no experience with old trees 

 of some of these varieties. From the same standpoint. Red 

 Astrachan, Windsor, Jonathan, Ingram, York Imperial, Ben 

 Davis, Gano, Northwestern, Missouri Pippin, Iowa Blush, and 

 Grimes Golden might be called fairly resistant to scab, while 

 Winesap, Mammoth Black Twig, Sheriff, RaUs Genet, Virginia 

 Beauty, Red June, and Northern Spy would be regarded as very 

 susceptible to scab. 



From publications of other Experiment Stations, notably Ala- 

 bama and Deleware, from reports received from a few fruit 

 growers in this State and from personal observation, the writer 

 has prepared the following provisional list of apples commonly 

 grow in Nebraska, arranged with reference to their resistance to 

 rust. Some of these varieties may have to be changed upon 

 further observation, and it is certainly desirbale to add to the 

 hst: 



