24 BULLETIN 299, U. S. DEPARTMENT OF AGRICULTURE. 



Black ash growing in swamps seems to be quickly affected by 

 drainage, and there are large quantities in gradually draining swamps 

 in New York and the Lake States either dead or dying. Excessive 

 transpiration kills these trees down from the top. 



In the culture of ash on sites subject to drought, plants from seeds 

 of drought-resisting trees should be used, and the area cultivated for 

 several seasons till good extensive root systems are developed. 



ANIMALS. 



The tender young shoots and leaves of small ash seedlings and 

 sprouts form unusually attractive browsing for wild animals, espe- 

 cially deer and cattle, which greatly reduces natural reproduction of 

 the genus and causes double leaders on many trees. Trees whose 

 crowns are above browsing distance are practically free from damage 

 by animals. 



DISEASES. 



Ash is not subject to extensive damage by diseases, which is an 

 important point in its favor. Only one (white rot) has done much 

 serious harm, though a number have been found on the different 

 species. Diseases on ash are confined for th« most part to trees 

 whose vitality has been weakened by old age, fire, or generally 

 adverse conditions. Ash stands grown under proper methods of 

 forest management should be practically immune from serious attacks. 



White rot occurs in the heartwood of the trunk and main branches, 

 and is caused by the fungus Polyporus fraxinophilus, which turns the 

 wood into a mass of yellow pulp. This disease is common in over- 

 mature green ash in the lower Ohio and Mississippi River bottoms, 

 near their confluence; also on white ash near the western limit of its 

 range in Iowa, Missouri, Kansas, and Oklahoma, on dry limestone 

 hills, where 90 per cent of the trees are infected. 1 The ash-leaf rust, 

 JEdduim jraxini, is probably the most common fungous parasite, 

 occurring on almost all species of ash, but doing little or no serious 

 damage. Other fungi appear on ash leaves and twigs, but rarely in 

 sufficient numbers to do serious injury to the trees affected. Among 

 them are several species of Glmosporium and Sphseropsis, as well as 

 Septoria Jraxini, Phyllosticta fraxini, and Sphseronema spina. 



INSECTS. 



During the last several years the oyster-shell scale (Lipidosaphes 

 ulmi) has increased so much on ash trees in northern Ohio as to kill 

 off entire stands, and is still on the increase in that locality. There 

 are a number of other insects which attack standing ash, but none 



1 Full discussion of this disease in Bulletin No. 32 of the Bureau of Plant Industry, '• A Disease of the 

 White Ash caused by Polyporus fraxinophilus." 



