REPORT OF THE SOCIETY 45 



ONION MAGGOT CONTROL 



On the farm of Mr. Jack McEvoy, Rosemount, Montreal 



1st plot next the highway above the storage. 



2 acres, requiring 40 pans. 

 2nd plot below far storage in the centre of the farm. 



13^ acre requiring 30 pans. 

 3rd plot just beolw the first storage house was sprayed with the watering 

 can diagonal bait. 



Pans set out and filled May 27— 28th. 



2nd. Refilled May 31 — Weather hot and dry. 



3rd. " June 6 — Owner refilled on the 2nd and again on the 



4th on account of heat and heavy rain 

 on June 3rd. 

 4th. " " 10—. 



5th. " " 15. 



Note: — The spraying was carried out each time the pans were filled. 



Summary of Observations 



I. — First, the two acre plot above the storage was 98% free of maggot injury. 

 l^Jumerous counts showed from 12 to 20 dead flies in and around the 

 pans. 

 II. — Secondly, the one and a half acre plot below the far storage showed very 

 little injury with the exception of the end near the manure pile next to 

 the storage. This end was attacked before we set out the pans as the 

 heating manure provided seemingly an ideal refuge against the cold 

 winds and nights. Observations during the flj^ period and latter 

 throughout the summer did not change the proportion affected by the 

 maggot, which was placed at 5-8%. 



III. — The third plot of four acres on which was tried the diagonal watering can 

 spray was situated just back of the first storage house. The results 

 here were not to be compared with the pan control as the spray seemed 

 to drj^ too quickly and as a result there were 20% or more of the 

 onions attacked by the maggot. This field was also attacked by onion 

 smut (Urocystis Cepidae) which further reduced the yield. 



lY. — The fourth plot of Mr. M. IMcEvoy's consisting of ten acres was left for 

 a check as he had not previously been bothered with this pest. How- 

 ever, on June 10th, the field was so badly attacked that Mr. ]\IcEvoy 

 secured 200 pans and treated the whole piece, which quickly controlled 

 the flies, as we counted in and around the pans twelve to twenty eight. 

 * Beyond patches here and there this field finall}' turned off a fair crop 

 of onions for the past season of good average size. 



These growers were very pleased with the results obtained from the pans 

 as they were easily and quickly refilled and did not hinder cultivation. They 

 did not, however, like the diagonal spray as it required twice the amount of 

 liquid and was not nearly so easy to apply. It required more material and 

 time to apply while the damage to the standing crop was only kept down by 

 carefully watching the rows. 



