473 REPORT OF TiiE SECRMAtlt OP THK 



I do not attach any great importance to mj own opinion as 

 to the cause of Yellows ; but if I should advance an opinion, 

 it would be that the Yellows was probably caused by a fungus 

 growth, and that liability to attack by this fungus was very 

 greatly increased by the fact of a tree's being in an enfeebled 

 condition from any cause. 



INVESTIGATIONS. 



By invitation of the Berrien County Horticultural Associa- 

 ^tlon, I visited Benton Harbor last Seijtember, inspecting a large 

 (jmmber of orchards, and examining as far as possible all classes 

 •of diseased trees. Many trees exhibited the well-known symp- 

 toms of the Yellows : viz.: purple blotches on the prematurely 

 ripened and somewhat insipid fruit, small wiry branches on 

 'the trunk and main limbs, bearing small leaves of a sickly 

 yellow color, and here and there upon the tree shriveled and 

 'dry peaches still adhering to the boughs. In many trees having 

 symptoms of the Yellows, peculiar brown spots were found in 

 the inner bark, next the wood ; but similar spots were found 

 in trees apparently healthy, and this indication was, therefore, 

 neglected. Some trees suspected of having the Yellows proved 

 to be injured by the borer. 



The soil occupied by peach orchards in Benton Harbor is 

 for the most part a gravelly loam, — what would be called a 

 quick and warm soil. In consequence of its porous nature, 

 vegetable matter or humus tends to rapidly disappear from the 

 soil. The liberal dressings of muck and marl which many 

 have applied to their soils, show an intelligent apprehension of 

 the nature and needs of their soil. 



I obtained, for a subsequent examination, specimens of dis- 

 eased wood (roots and branches) leaves, fruit, and a quantity of 

 ashes secured by burning the wood of a tree unmistakably dis- 

 eased with the Yellows. 



MICROSCOPIC EXAMINATION. 



Specimens of all the diseased structures, including the wiry 

 shoots, leaves, bark of root and branches, and the fruit, were sub- 



