370 Fruit-growing in Arid Regions 



are eighty trees to the acre, it will require sixty-four tanks cf two 

 hundred gallons each to make the application. 



If the weather is warm, some varieties will close their calyxes 

 within six days from the time the petals are off, and the little 

 apples that close their calyxes first are the ones most likely to 

 set and make fruit. 



When making the first spray, the grower must determine upon 

 one thing, if he is to get anything like perfect fruit, and that is 

 to stay with each tree until every calyx has been filled with the spray. 

 He should stop occasionally and examine the blossoms to find 

 out whether this is being done. 



With large trees always have a tower or platform above the 

 tank where two men may stand with long rods to spray down- 

 ward while one or two men with short poles upon the ground 

 spray upward through the trees. 



A pressure of one hundred to one hundred fifty pounds is suf- 

 ficient to do good work, if proper nozzles are used. 



San Jose Scale. See under Plum. 



DISEASES OF THE APRICOT 



Blight (Bacillus amylovorus). The germs of pear-blight occa- 

 sionally attack apricot trees. The twigs and branches are killed, 

 and the fruit rotted much the same as pear or apple trees are 

 attacked. 



The only remedy is to cut out and burn the infected parts. 

 See Pear. 



San Jos6 Scale. See under Plum. 



INSECTS OF THE CHERRY 



Pear-tree Slug (Eriocampoides limacina). While the slug is 

 primarily a pear-tree insect, it is more common on cherry trees. 

 It is the larva of a fly, slimy in appearance, resembling a snail. 

 It feeds on the upper surface of the leaves, rapidly skeletonizing 

 them. It is common to see cherry trees denuded of foliage by 

 these insects in midsummer. This results in serious damage to 

 the trees ultimately, but there is no excuse for such injury as the 

 slugs are easily controlled. 



