REPORT OF THE HORTICULTURIST. 109 



TREATMENT OF APHIDES IN THE ORCHARD. 



It is not often that orchard trees under good cultivation suffer from the attacks of 

 aphides. The summer of 1897 was marked by the most serious visitation of this little 

 insect that I have known. Plum trees were severely attacked throughout Ontario and 

 Quebec. Cherry trees in some instances lost their foliage in midsummer, while in bad 

 cases the growth of vigorous apple trees was completely arrested in midseason. The 

 attack began in spring with the unfolding leaf buds and was continued with more or 

 less vigour till the leaves fell. Two weeks of fiercely hot weather in July and again 

 towards the end of August retarded the increase somewhat, but the check was only 

 temporary. Nursery stock and young orchard trees suffered most. The Farm orchards 

 were sprayed four times to prevent injury from this little pest. Among remedies the 

 following were tried : — 



KEROSENE EMULSION (Riley-Hubbard formula). 



Rolfe apple tree. — Applied June 15. Examined June 16. A few (about 10 per cent) 

 of aphis killed. Sprayed again June 17. Examined June 19. About 20 per cent of 

 aphis killed. Leaves of tree quite rusty ; considerably injured by spray. 



Rubicon apple tree. — Sprayed June 28. Examined June 29. Not more than 10 

 per cent killed ; foliage slightly spotted. Sprayed again July 3. Examined the follow- 

 ing day. About 50 per cent of aphis killed ; foliage considerably injured. 



Borsdorf apple tree. — Sprayed June 28. Examined June 29. About 80 per cent 

 of aphis killed. Foliage badly injured. Sprayed again July 3. Examined July 5. Aphis 

 nearly all dead, but foliage badly injured. 



In every case where kerosene emulsion was used two or more times, the foliage 

 was considerably injured although every care was exercised in preparing and applying 

 the emulsion. For this reason other insecticides were tried. 



TOBACCO WATER. 



Made by soaking 8 lbs. of home grown tobacco leaf and stems in a barrel of water 

 for 48 hours with 2 lbs. of soft soap added, applied to Scotts Winter. Three applica- 

 tions completely cleared the tree. 



Rolfe apple tree. — Treated June 25. Examined June 26. About 50 per cent of 

 aphis killed. Sprayed again June 26. Examined June 28. No living insects visible. 



Fanny apple tree. — Treated on June 24, and again on the 26th. Examined June 

 28. A few colonies were found upon twigs that were not thoroughly sprayed. 



Ordinary tobacco waste did not give satisfactory results. Three sprayings of 

 tobacco water made from this material only killed about 50 per cent of the insects upon 

 a Rubicon apple tree. The efficacy of this brand was increased by soaking the stems 

 in hot water. One application destroyed about 95 per cent. 



A tree of the Peter apple, sprayed once with tobacco decoction prepared as just 

 described, was cleared of aphis on July 14, by one application. 



TOBACCO WATER AND LEMON OIL. 



One half pint of lemon oil was added to five gallons of water. This was applied to 

 a badly infested Scotts Winter apple tree. A single application completely ridded the 

 trees of aphis. The foliage and young wood were somewhat discoloured, but did not ap- 

 pear to be injured. 



QUASSIA CHIPS AND WHALE OIL SOAP. 



To prepare : — Quassia chips, 4 lbs., boiled ^ an hour in 4 gals, water. Whale oil 

 soap, 2 lbs., stirred in. Diluted to 1 barrel or 45 gals, water. 



