94 PROTECTION OF PLANTS 1922-23 



SOME RESULTS FROM SPRAYING & DUSTING APPLES IN QUEBEC. 



By C. E. Petch, Dominion Entomological Laboratory, 

 Hemmingford, Que. 



During the past four years four spraying systems have been tested in the 

 same orchard on the same variety. The variety chosen was Fameuse, because 

 it is very susceptible to apple scab (Venturia pomi) and many of our common 

 insects, especially apple maggot (Rhagoletis pomonella). 



The spraying schedules used were as follows: 



Plot no. 1 — nova scotia spray calendar 



Green Tip Spray — Bordeaux 3-1 0-40 + arsenate of calcium 1 lb 



Pink Bud Spray • — ^Bordeaux 2-1 0-40 + arsenate of calcium 1 lb 



Calyx spray — Soluble sulphur 1 lbs; hydrated lime 5 lbs; cal. ars. 3^ lb 



After calyx spray — Bordeaux 2-10-40 — arsenate of lime 1 lb. 



Plot no. 2 — Ontario spray calendar 



Green Tip spray — Lime sulphur 1 gal. to 20 water 

 Pink Bud spray — Lime sulphur 1 — 40 + arsenate of lead 13^ — 40 

 Calyx spray — Lime sulphur 1 — 40 + arsenate of lead 1—40 



After calyx spray — Lime sulphur 1 — 40 + arsenate of lead 1 lb — 40 



plot no. 3 



Green tip spray — Lime sulphur 1.008 sp. gr. + calcium arsenate "^ lb — 40 

 Pink bud spray — Lime sulphur 1.007 sp. gr. + calcium arsenate % lb — 40 

 Calyx spray • — Lime sulphur 1.006 sp. gr. + calcium arsenate ^ lb — 40 



After calyx spray — Bordeaux 3 — 10 — 40 + calcium arsenate lib — 40 



plot no. 4 



Pinkbudspray — Lime sulphur 1.010 sp. gr. + calcium arsenate M lb — 40 

 Calyx spray — Lime sulphur 1.009 sp. gr. + calcium arsenate ^ lb — 40 



After calyx — Lime sulphur 1.007 sp. gr. + calcium arsenate % lb— 40 



Spray 2 weeks later — Lime sulphur 1.007 sp. gr. + calcium arsenate % lb — 40 



As often as possible the applications were made on the same day and there 

 was never over 24 hours between any of them. The average of the injuries for 

 the past four years has been as represented in the following table: — 



plot scab insect injury russeting foliage injury 



No. 1 1.86% 2.5 % 9.25% 2.5 % 



No. 2 1.39% 2.0 % 0.0 % • 3.75% 



No. 3 .85% 1.63%o 1-25% 2.50% 



No. 4 1.34%, 1.55% 0.0 % 4.25% 



