EXPERIMENT STATION BULLETINS. 411 



growers that do not mound, do leave the soil out of the pit around the 

 base of the tree in "worming" until it fills during the summer, thus 

 allowing time for the sun to dry the wounds and toughen the surface. 

 There is also present in Michigan the Lesser Peach-borer, which works 

 more in the body and limbs, and the upper part of the tree. 



Paradichlorobenzene is a solid crystalline substance, the use of which, 

 in this connection bids fair to supercede the practice of "worming" 

 peach trees just described. Recent experiments seem to show that it 

 will kill borers in the crown and roots which lie below the line of the 

 application, without injury to the tree. Undoubtedly extensive use of 

 this comparatively new method will develop new kinks and make its 

 use more safe to the tree. Thus far its use seems to be restricted to 

 trees of six years or older. 



The dose usually applied is % ounce or 1 ounce to a tree, the cry- 

 stals being fairly fine aud all lumps crushed and screened. Prepare 

 the tree by clearing away weeds, grass, leaves, etc., from about the base 

 of the trunk, clearing a space but not loosening the soil, and distribute 

 the crystals in a narrow band one inch wide and two inches from the 

 trunk of the tree. Then place several shovelfuls of soil about the tree 

 over the crystals, so as not to disturb them. The best time to apply 

 seems to be the last week of August or the first week of September and 

 the soil should be left undisturbed for three or four weeks after which 

 it should be pulled away from the tree, in order to avoid an over-dose. 

 More detailed directions will be furnished on request by the Department 

 of Entomology. 



PEACH YELLOWS. 



This is a veiy infectious disease the cause of which is unknown. The 

 first symptoms in a young tree, previous to bearing, are indicated by 

 the leaves of one or two limbs turning from a rich dark green to a 

 "j^ellowish-green or reddish-rusty-green" color; this is accompanied by 

 a rolling of the leaves from their edges. These leaves ripen and fall 

 earlier than normal leaves. The fruit-buds are larger and more ma- 

 ture in appearance and in the spring will invariably bloom earlier than 

 healthy buds. In some instances, the symptoms are not confined to 

 one or two branches, but many of the leaves in the center of the tree 

 turn yellowish or light-green, roll slightly at their edges and droop con- 

 siderably. These latter symptoms are often present in case of "Little 

 Peach." 



Upon bearing trees, there may be any one or all of the following 

 symptoms: The fruit may ripen prematurely — one to three weeks — 

 upon one or two branches or over the entire tree. The fruit may have 

 numerous red spots on the surface, the spots sometimes extending in 

 red streaks partially or wholly through the flesh to the pit. Often the 

 flesh, about the pit is full of radiating streaks of red. The surface of 

 the fruit may be smooth or considerably roughened and the flesh more 

 or less stringy and very insipid. The leaves may be yellowish, pale 

 or reddish rusty-green in color, usually rolling and drooping. In ad- 

 vanced stages, numerous finely branched shoots bearing many slender, 

 sickly leaves, appear on the trunk or main limbs and sometimes near 

 the ends of the branches. Finally the tree dies. 



Winter injury to the bark of the trunk or main limbs, mechanical 



