4(52 



THE MONTHLY BULLETIN. 



drive through Hie residence portion, Ihcy may see hanging to the trees the sign 

 that is sometimes seen fastened to the fences when the roses are in bloom, "Strangers 

 are invited to help themselves." Then the avocado fruit will make itself known to 

 thousands of people who now think that the alligator pear is a kind of wild animal 

 food. 



APRICOT TROUBLES. 



By Earl L. Morris, County Horticultural Commissioner, San Jose, Cal. 



The following is a popular account of two abnormal conditions which may arise 

 during the early life of an apricot orchard. There has been a tendency to include 

 both of these and others under the term "sour sap," which may be used to indicate 



conditions resulting in the dying and later souring of 

 the cambium layer, the growing portion of the tree 

 between the bark and the wood. In fact, this term 

 has been applied to conditions not even characterized 

 by sour sap. 



Often in young orchards from one to three years 

 old many trees fail to start normally in the spring 

 or having started die back in from 30 to CO days. 

 In either case an examination shows the roots to be 

 in good condition but reveals a dead, sour cambium 

 layer nearly or quite surrounding the tree generally 

 near or at the ground. 1'sually in such cases a 

 vigorous shoot appears just above the union which 

 will make a large tree much quicker than one can be 

 grown from a replant since the root system is 

 already established. If for reasons to be discussed 

 later it seems best to replant there need be no fear 

 of a fatal disease passing from the dead tree to the 

 replant in the same hole. If a tree is grown from 

 the old root and new shoot the great danger is that 

 fungi causing wood decay may find entrance where 

 the dead stump has been removed before the new growth has closed over it, and that 

 in ten or fifteen years the tree will be weak at that point. Great care must be 

 taken to protect the wounds and even then there is danger of infection. 



Whether it is best to try to make a tree from a sound root which has been in 

 orchard form more than one year, if the whole top must be removed, or whether it 

 is best to replant, can be determined only by future observations. That a good 

 growth will come from such a root is certain. Two years time and the cost of trees 

 and labor is very little compared with the possible loss of trees after they have come 

 into full bearing. Some orchardists believe that either method is safe while others 

 hold that replanting is necessary. There do not seem to be any carefully recorded 

 observations to determine this point. Further discussion might prove helpful. 



Another condition wholly distinct from the above is found to be most serious in 

 trees from three to eight years old. It does not show in the spring. The trees 

 grow normally until about the first or middle of June when the leaves at the tip 

 of a branch wilt rather suddenly. This wilting may extend to other branches and 

 in some instances over the whole tree. The first wilting may appear any time from 

 June to November. The affected portion may make a feeble effort to put out new 

 leaves which never amount to anything. Except in very severe cases the portion of 

 the tree below the wilt will start and grow normally the next spring. The wilt may or 

 may not appear later. The fact that a few trees in an orchard are affected does 

 not mean that all the trees will become so. Neither does it mean that the particular 

 diseased trees are necessarily going to die. A few may die but if proper precautions 

 are observed most of them should make good profitable trees. Examination of a 

 cross section of an affected limb shows brown or black heartwood, which has given 

 rise to the local name of "blackheart." Investigations carried on by the Depart- 

 ment of Plant Tathology of our State Experiment Station show this trouble to be 



