352 MAINE AGRICULTURAL EXPERIMENT STATION. I9IO. 



one or more kinds are probably parasitic. However, all are 

 agreed that lichens are decidedly objectionable on fruit trees. 

 They harbor insects and fungi, tend to keep the branches moist 

 and more likely to decay, besides being untidy and unsightly. 

 While they may not secure any nourishment from the trees they 

 certainly must interfere seriously with the functions of the bark 

 on the younger limbs. 



Two or 3 pounds of copper sulphate to 50 gallons of water or 

 a 5-5-50 bordeaux sprayed on the trees before the buds swell in 

 the spring will generally destroy the lichens. A wash such as is 

 ur.ed for borers consisting of one pound of potash or concen- 

 trated lye to 5 gallons of water, put on with a brush, is said to 

 be effective. None of these materials should he sprayed on the 

 trees when in, leaf on account of injuring the foliage. Thorough 

 spraying with 3-3-50 bordeaux in the spring and early summer, 

 as recommended for apple scab and other fungous diseases, 

 would doubtless do much to hold the lichens in check, if not de- 

 stroy them altogether. Hence, if the orchard is well cared for 

 and sprayed it will not be infested with lichens. 



Parasitic Diseases. 



diseases of the foliage and eruit. 



Scab. Probably no other disease of the apple is of so much 

 economic importance to Maine orcharding as the common apple 

 scab caused by the fungus Venturia pomi (Fr.) Wint, The 

 losses from this disease are not so much in the destruction of the 

 fruit as in the lowering of its market value. On account of the 

 attacks of this one disease, which is largely preventable, the 

 financial returns from the orchards of many sections of the 

 country are reduced from 25 to 50 per cent yearly.* Were it 

 properly controlled in Maine a large proportion of the crop of 

 some varieties which now goes as No. 2 and No. 3, might be 

 marketed with the No. i grade. Moreover where spraying op- 

 erations have not been generally practiced the importance of 

 this fungus is in no way realized. For years it has been com- 

 mon and widespread, particularly on certain varieties and the 

 Orchardist has learned to regard it as one of the things to be 



Duggar, B. M. Fungous Diseases of Plants, p. 265, 1909. 



