DISEASES OF CULTIVATED PLANTS 485 



in advance of the normal season of ripening. The prematurely 

 ripened fruit almost invariably has a characteristic appearance which 

 a careful observer can detect. Instead of uniform masses and blend- 

 ing of color the fruit has a red spotted or blotched appearance ; these 

 red spots or blotches may be few or numerous and occur largely near 

 the surface or through tne flesh to the pit. The flesh surrounding the 

 pit is also usually much more red than in normal fruit. In some 

 instances affected trees produce fruit which is very highly colored and 

 the red spotting is almost obscured. Specimen fruits will sometimes 

 be found upon diseased trees which fail to show the characteristic red 

 spotting although the flesh about the pit will usually indicate yellows. 

 Sometimes only one branch of a tree will apparently be affected and 

 while the fruit upon this affected branch is prematurely ripe the fruit 

 upon the remainder of the tree will be entirely green. 



The flavor and quality of the premature fruit is somewhat vari- 

 able. When it ripens several weeks in advance of its normal season 

 it is usually under normal size, watery fleshed, insipid and sometimes 

 bitter. When the fruit ripens at about the normal time, however, 

 it may be of fair quality. Such fruit usually occurs upon trees which 

 have apparently been affected only for a short time. 



Peach trees sometimes produce premature fruit because of gird- 

 ling by borers or other injuries, but such cases can readily be deter- 

 mined from yellows. The premature fruit caused by yellows is very 

 susceptible to the brown rot and decays rapidly under conditions fa- 

 vorable to that disease. 



Another prominent symptom of yellows is the characteristic 

 development of slender, wiry, yellowish-green shoots upon the trunk 

 and lower branches of affected trees. The leaves upon these shoots 

 are smaller and more narrow than upon healthy twigs besides having 

 a starved, sickly, greenish-yellow appearance. The characteristic 

 shoots sometimes develop at the tips of branches as well as upon the 

 trunk and lower limbs. In some instances, only a few of these slen- 

 der, wiry shoots are produced on each tree while in other cases they 

 push out over the entire tree. Affected trees can often be detected in 

 the dormant season by this wiry twig development. Occasionally these 

 wiry twigs will make a late fall growth and retain leaves for a time 

 after the other branches are dormant. 



In advanced stages of yellows the premature red-spotted fruit 

 and the weak, sickly appearing shoots are commonly found upon each 

 tree, but in the earlier stages the red spotted premature fruit may 

 appear first and in other cases the slender shoots. Trees affected with 

 yellows commonly have a sickly, yellowish-green appearance, and the 

 diseased trees in an orchard can be detected from a distance because 

 of this. Closely observe the behavior of each tree in the orchard 

 from the beginning. If symptoms of yellows or little peach appear in 

 any tree, pull it out at once and destroy it by burning. Do not allow 

 an affected tree to remain in the orchard from fall until spring. 



Individual trees which grow very poorly in a yoiino; orchard arc 

 of doubtful value whether affected with yellows or not and had best 

 be pulled out and replaced by others. In certain special cases where 



