1562 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



Little Leaf— California Yellows 



Characterized by the development of 

 spindling, yellow, sickly looking shoots 

 on the new growth, with small, narrow, 

 yellow leaves. The leaves along the 

 shoots drop off during the summer, leav- 

 ing tufts at the ends. Fruit fails to 

 develop, shrivels and drops. Worst on 

 trees from three to seven years old. 



This trouble also attacks other stone 

 fruits, walnuts, pecans and other trees. 

 Always worst on lighter, drier soils, this 

 feature showing itself by the more pro- 

 nounced occurrence of the disease on 

 trees standing in sandy streaks or slight 

 elevations in the orchard. 



This trouble has no relation to the 

 true Eastern peach yellows, but is de- 

 cidedly climatic and seasonal in its ap- 

 pearance. Occurs mostly following un- 

 usually dry seasons, on trees standing 

 in light soil or one underlaid with a 

 coarse, sandy subsoil. Trees on a fairly 

 heavy subsoil, or those which have re- 

 ceived abundant irrigation throughout 

 the preceding season, are decidedly free 

 from the trouble even in the worst af- 

 fected localities. Appears similar in na- 

 ture to "mottled leaf" of the orange, and, 

 in fact, orange trees growing near 

 peaches affected by "little leaf" show a 

 typical "mottled leaf" condition. Many 

 other kinds of trees are also more or 

 less affected. 



In most cases, regular irrigation dur- 

 ing the summer shows a marked effect 

 in controlling this trouble. Such irriga- 

 tion should be given particularly in the 

 latter part of the season, after the crop 

 is off, especially when the rains are late 

 In commencing. 



Climatic Effect 



The trees fail to leaf out properly in 

 the spring and seem to become confused, 

 so to speak, as to the season. Later in 

 the summer the trees may bloom and 

 leaves begin to appear, but the 'tops 

 usually die back nearly to the forks 

 of the tree and sometimes the trees die 

 entirely. If not too badly affected, the 

 tree sends out new sucker growth from 

 the trunk and base of the main limbs. 



Plums, apricots, apples and other trees 

 are sometimes affected. 



This trouble is one which occurs 

 mostly in the southern part of the state 

 as a result of unseasonable climatic con- 

 ditions. It is usually most pronounced 

 in seasons when a period of warm, stimu- 

 lating rains in the winter is followed by 

 a long, cold spring. Similar results are 

 also produced by an abnormal, dry fall, 

 throwing the trees into a dormant con- 

 dition, followed by warm, spring-like 

 weather accompanying the winter rains. 

 These combinations and various others 

 often have unfavorable effects upon trees 

 which are accustomed to a definite rest- 

 ing period during the winter. Many 

 peculiar diseases of deciduous fruits de- 

 scribed in this bulletin under various 

 names, such as "die back," "yellows " 

 etc., are no doubt contributed to by such 

 disturbances in the normal period of 

 dormancy. Every few years there is 

 usually a season, especially in the south- 

 ern part of the state, when deciduous 

 trees are badly affected in such ways as 

 these. 



Following such an attack trees should 

 be pruned back to healthy, vigorous 

 wood, when they will usually form a new 

 top and come back into good condition 

 again. With peaches it is noticeable that 

 varieties of the saucer or Peen To type 

 are not affected in this manner, as are 

 the Persian varieties. 



R. E. Smith, 



California Experiment Station Bulletin 218 



Bibliography 



Ohio Experiment Station Bulletin 214. 



California Experiment Station Bulletin 



218. 



Ontario Department of Agriculture Bul- 

 letin 201. 



PEACH PESTS 



Apple Tent Cateepillab. See Apple 

 Pests, 



Black Peach Aphids. See ApMds. 



Brown Mite 



BryoMa pratensis Garman 

 The young mites hatched from eggs 

 early in spring are bright red and have 



