472 INSECTS AFFECTING VEGETATION 



criminal deception. Various secondary causes may contribute to the 

 dying of such trees as we have described, but such factors are usually 

 of little importance, and in many cases are an actual blessing to the 

 owner in hastening the time when his expenditures for the mainte- 

 nance of such an orchard are brought to an end. (Cal. E. S. B. 218.) 

 Other Almond Diseases. Yellows (See page 482) ; Crown 

 Gall (See page 451). 



DISEASES OF APRICOTS. 



Shot-hole and Fruit Spot. This fungus is the same as that 

 causing the peach blight and produces in the apricot a spotting of 

 the fruit, shot-hole effect in the leaves and killing of the <buds. Spray 

 w T ith Bordeaux mixture during November and again in spring just 

 as the buds open. (See Bulletin 203, page 33, California Experi- 

 ment Station.) 



Bud Blight. Characterized by a dying of the buds during the 

 early winter and caused very largely <by the fungus just mentioned. 

 Similar trouble is caused more or less by sour sap conditions. 



Scab. Causes a scabby spotting on the surface of the fruit. 

 Has never been sufficiently serious to warrant treatment in Cali- 

 fornia. 



Brown Rot. A decay of the fruit while still on the tree, oc- 

 curring some seasons in the vicinity of San Francisco bay and other 

 moist localities. The young growth as well as the fruit is also some- 

 times affected, the new shoots wilting and dying back from the at- 

 tacks of this fungus. This is the most serious obstacle to stone fruit 

 production in the eastern states, but does not find sufficient moisture 

 for its development in California, except on early varieties in occa- 

 sional seasons of late rains in the localities mentioned above. No 

 definite remedy for this trouble has been demonstrated in California, 

 but spraying with self-boiled lime sulphur just as the fruit 'is setting 

 and again with the same following subsequent rains is recommended 

 for trial. 



Blossom Rot. The young fruit decays while still very small 

 and enclosed by the calyx or outer cup of the blossom. The trouble 

 occurs when wet rainy weather prevails during the time of fruit 

 setting. It commences in a rotting of the calyx cup, which is dead 

 and susceptible to decay by saprophytic fungi, which decay spreads 

 to the young fruit. It is caused by various fungi, of which perhaps 

 a species of Sclerotinia, apparently S. libertiana, is most common, 

 causing a decay of the young fruit on the tree. When such fruit is 

 picked and placed in a moist chamber it develops an abundant cot- 

 tony mold in which black sclerotia soon forms. This appears to be 

 the same fungus causing the cottony mold or white rot of the lemon 

 storage. Botrytis vulgaris is also common in this trouble. Same 

 treatment as brown rot. Spraying for shot-hole fungus might also 

 be of some benefit in this trouble. 



Sour Sap and Seasonal Effects. The apricot is particularly 

 sensitive to sour sap (see Almond) and other seasonal effects. It is 

 a tree having a free flow of sap, quick to respond to stimulating in- 

 fluences and one having the characteristic of all the stone fruits of 



