96 PROTECTION OF PLANTS — 1922-23 



These results show that this material has not given satisfactory control of 

 apple scab on our most important varieties. When used at a strength over 3 

 lbs to 40 gals, it is more costly than commercial liquid lime sulphur. From my 

 experience it has no advantages in handling. The only place for its vise at the 

 present time is with the very small grower, where the quantities used would 

 be trifling. 



Dusting continues to give satisfactory results in some orchards and this 

 year in one orchard apple scab was present on only 1% of the Fameuse apples. 

 In this orchard the expensive mixtures were not used but mixtures containing 

 50% sulphur 45% talc or hydrated lime and 5% insecticide. The use of these 

 diluted mixtures reduced the cost almost 50%. The use of Bordeaux dusts has 

 given bronzing and russetting every year and it has been decided not to recom- 

 mend their use in this province. Calcium arsenate has been used at rates of 

 5% to 10% of the mixtures containing no hydrated lime and there has not been 

 any foliage or fruit injury during the past six years. Materials for increasing 

 the adhesion of dusts to foliage and fruit are greatly needed but to my knowledge 

 there are none known at the present time which are satisfactory. Among the 

 many things tried wheat flour was the only one that gave promise of being worth 

 while in orchard dusting. Further experiments with wheat flour at various 

 strengths are to be carried out in 1923. 



The above remarks are relative to this province and I would advise those 

 living outside Quebec not to adopt any of the above mixtures in a commercial 

 way unless they have been tested and found satisfactory for their conditions. 



RESULTS OF ONION MAGGOT CONTROL WORK, 1922. 

 By W. J. Tawse, Dept. of Horticulture, Macdonald College. 



The onion maggot (Pegomyia ceparum, Bouche) control work was again 

 carried on under field conditions both at the College and with co-operating 

 market gardeners around Montreal. The pan system of setting out the 

 poisoned bait w^s used entirely as the diagonal spra}- was too costly, both 

 as regards time and material and further under local chmatic conditions the 

 results were very uncertain. The dry hot winds at this period of the growing 

 season have completely evaporated other sources of moisture and in consequence 

 the maggot flies or adults are quickly attracted to the pans of poisoned bait. 



It is to be regretted that Mr. Sauv6 on the Cote des Neiges Road was 

 unable to carry on the experiment after setting out the pans and filling them 



