166 Missouri State Hortimdtural Society. 



We rather incline to this theory as the first cause, followed by 

 the work of the aphis. 



Last spring, a curl similar to this affected both pear and apple 

 trees, resulting in much indifferent and scabby fruit. 



The yellows, in the first appearance of this malady, the young 

 twigs on the tree become sickly, growing slender and wiry, the 

 leaves yellowish, pale and small. The fruit ripens, two or four 

 weeks before its proper season. During the first year the peach 

 may attain its full size, then decreasing as the strength of the tree 

 weakens. Varieties that are most vigorous and healthy have' been 

 found more subject to be attacked than those of a slower growth. 



Prof. Penhallovv regards this disease the result more of a 

 deficiency, or an excess of proper nutriment in the soils, than 

 insects or fungus. Though the latter, after the tree is diseased, 

 help on the destruction. 



Downing and Elliot hold similar views. The former believes 

 the malady to have first been produced by bad cultivation, and the 

 exhaustion of the soil by overcropping, the continued sowing and 

 planting of seed and trees from stocks so enfeebled. 



Thus far, in the west, the yellows have not been troublesome 

 to the planter. Mention is made in our journals, of their ap- 

 pearance in some parts of the Michigan peach region, where the 

 soils are light and sandy. Why its appearance exists in some 

 localities more than others we quote from Downing, some facts 

 bearing on the subject : 



'^For upwards of a century after the peach tree Avas intro- 

 duced it was cultivated everywhere, — the great natural fertility of 

 the soil was unexhausted, lands occupied by orchards were seldom 

 put to any other use, most of the soils of these states ( Md., N. J. 

 Del., and Virg. , ) at first though naturally rich, was light, warm 

 and sandy. Peach trees here always produced to excess — soon 

 impoverishing the soil. In these fields the disease first appeared 

 and gradually spread." 



Trees that were affected, have been recovered by salt, lime or 

 ashes worked into the soil, and cutting back the trees one-half. 



Some believe the disease to be contagious. Xursery men 

 should not plant seeds for stocks, from regions so infected — diseased 

 trees should be burned and fresh situations chosen for orchards. 

 These when properly cultivated, manured and trimmed, the 

 original health and longevity of the tree will be established. 



The commercial value of the peach product is estimated at 

 upwards of sixty million dollars annually. This is on the increase. 



