1891.] ESSAYS. 10!) 



The ai)plo tree is less subject to disease than any of tlie tree 

 fruits and its principal enemies are the borer, canker worm and 

 codling moth. Many young trees are destroyed by the borer ; 

 the eggs are deposited in the bark, generally at or near the 

 ground ; they hatch from the middle of July to the last of 

 August. Various washes are recommended for destroying this 

 pest which may prove more or less eftectual, but a sure remedy 

 is in a careful examination of the trees the last of July and 

 again the first of September ; as soon as the eggs hatch the 

 young borers commence operations and cause a moist spot and 

 discoloration in the bark easily seen and they may be quickly 

 removed with the point of a knife. If any have escaped the 

 previous year they will have eaten through the bark, and tho 

 dust or chips made in their progress through the wood will 

 be seen at the base of the tree, which betrays their presence ; 

 they usually ascend the trunk and if their course has been 

 straight they may be easily removed with a small wire ; if the 

 course is irregular and they cannot be reached with the wire, 

 the track should be followed with the knife or small gouge 

 until they are found. If undisturbed they will remain tenants 

 three years ; it is a case where eviction is not only justifiable but 

 desirable. 



The arsenites have been found the most eftective means of 

 destroying the canker worm, either Paris green or London 

 purple is generally used ; as the latter is more soluble in water 

 it is more easily applied ; mixed with water at the rate of one 

 pound to two hundred and fifty gallons, one application 

 thoroughly wetting the leaves has been found sufficient, but if 

 the application is soon followed by rain it will be necessary to 

 repeat it ; the application is made with a hand pump having a 

 hose attachment having a nozzle throwing a fine spray. Ex- 

 periments by Prof. Cook seems to prove that the same mixture 

 applied to the trees as soon as the blossoms have fallen has 

 destroyed a large portion of the codling moths. 



The apple under ordinary conditions is a biennial crop the 

 trees bearing in a fruitful year so profusely that they make 

 little growth and few if any fruit-buds. The bearing year for 

 10 



