FOR PROFIT. 151 



need four or five washings instead of one, if done at 

 first spring sight of the insects, even repeated spray- 

 ings will not effect a complete cure owing to the great 

 difficulty of spraying the fluid into the curled foliage. 



The second vulnerable period is in the autumn. 

 Owing to the migratory habit above referred to, it is 

 often noticed that an orchard suffering severely may 

 be in a few days entirely free, though no washing 

 has been done. Growers must be on the watch in 

 the autumn for the return of these Aphis for their 

 egg laying. The leaves will not then be curled, and 

 spraying at this time, especially in the case of the 

 Apple Aphides, must be carried out with vigour. It 

 must also be done in the case of non-migratory species, 

 again in autumn, as the prevention of egg laying, 

 which begins about September, will mean a clean 

 orchard the following year. 



FAILURE OF FRUIT TREES TO CROP. There are 

 many reasons why trees fail to bear fruit, the principal 

 of which are as follows : When trees bloom, but set 

 no fruit, spring frosts may be suspected, or an insect 

 or fungoid attack may destroy the young fruit see 

 for Pears, the Midge ; Apples, the Apple Sucker and 

 Weevils ; for Acid Cherries, the Brown Rot. 



When no bloom is present, the failure may be due 

 to lack of fruit buds through too strong a vegetative 

 growth (see Root pruning), or to birds having, in 

 winter, destroyed the buds. Plums and Gooseberries 

 frequently fail from this cause, and the remedy is 

 obvious. If the birds cannot be destroyed, lime- 

 washing the trees may keep them off, and for low 

 bushes, black thread spun from twig to twig will 

 frighten them by entangling their feet and wings. 



