The Canadian Horticultun^ 



Vol. XXXVII 



APRIL, 1914 



No. 4 



What Spray Mixtures Shall Wc Use ? 



Prol. L. Caesar, Provincial Entomologist, Guelph, Ont. 



I HAVE been asked several times what 

 spray mixtures I should recommend 



for fruit trees this coming season. The 

 following in my opinion are the best : 



For the dormant spray lime-sulphur, 

 either commercial or home-made. If there 

 is San Jose Scale in the orchard the com- 

 mercial should not be used weaker than 

 about one gallon diluted to eight, or a 

 specific gravity reading on the hydrome- 

 ter of 1.032 to 1.035. Weaker solutions 

 often fail to give good results. If there 

 is no scale, either Oyster Shell or San 

 Jose, the wash may be diluted one gallon 

 to eleven or twelve. On peaches this 

 should be applied early before the buds 

 have any more than begun to swell, but 

 on apples or pears it may be applied any 

 time, say from two or three weeks be- 

 fore the buds burst right up to the time 

 they are bursting. On plums and cher- 

 ries it is better postponed until a few 

 days before the buds burst. 



For the second application on apples 

 and pears, which should be just before 

 the blossms begin to open, — the earliest 

 varieties being sprayed first, — either 

 lime-sulphur of the specific gravity 

 strength of i.oio or 1.009, which is 

 equivalent to the commercial diluted not 

 more than about one gallon to thirty, or 

 bordeaux mixture four-four-forty, should 

 be used as the fungicide, the latter being 

 given the preference. To each forty gal- 

 lons of either of these mixtures two or 

 three pounds of paste arsenate of lead 

 should be added as a poison. 



To prevent apple scab this application 

 should be done very thoroughly and as 

 near the time advocated as possible. 

 Many tend to overlook the importance of 

 this spraying but after such a bad season 

 for scab as we had last year, the greatest 

 care should be taken this season. 



The second application for plums and 

 cherries should be in about. a week after 

 the blossoms have fallen or as soon as 

 the fruit is well set. The same mixtures 

 should be used as for apples but in the 

 case of Japanese plums and possibly 

 sweet cherries the lime-sulphur should be 

 a little weaker. 



If peaches receive a second application 

 paste arsenate of lead alone, two or three 

 pounds to forty gallons of water should 

 be used when the fruits are formed, and 

 about one-third of an inch in size. The 

 object of this spray is to destroy the 

 plum curculio in the peach. 



The third application for apples and 



pears should be, especially in the case of 

 apples, as soon as from eighty to ninety 

 per cent, of the blossoms have fallen, be- 

 ginning with the earliest varieties. By 

 this time the bees will have almost aban- 

 doned the trees and gone to other flow- 

 ers. For this application it is not advis- 

 able to use bordeaux mixture for these 

 fruits as it often causes russeting, in- 

 stead I prefer lime-sulphur of the strength 

 of about 1.008 specific gravity, which is 

 equivalent to one gallon of the commer- 

 cial diluted to from thirty-five to forty 

 gallons. To every forty gallons of this 

 diluted mixture two pounds of the paste 

 arsenate of lead should be used. More 

 than this is not necessary but does no 

 harm. This is the great application for 

 codling moth and apple scab, and the 

 trees cannot be loo thoroughly and 

 promptly sprayed. 



For cherries and plums the third ap- 

 plication should be about two weeks after 

 the second and the same fixtures as for 

 the second may be used. 



If the weather in about ten days after 

 the third application is cold, dark and 

 wet it will be absolutely necessary to 



give a fourth application for apples and 

 pears with the same mixtures as for the 

 third, otherwise there will be an attack 

 of apple scab, especially in varieties like 

 Snow and Mcintosh. If the weather, how 

 ever, is dry and warm there is no need 

 for this application except in the far 

 eastern part of the province where it 

 should always be given. 



Cherries should receive a fourth ap- 

 lication with the above mixture or bor- 

 deaux as soon as the fruit is off to pre- 

 vent leaf spot. Plums that are inclined 

 to rot should be sprayed as late as pos- 

 sible without danger of staining the fruit 

 for market, either lime-sulphur or bor- 

 deaux being used. Peaches may receive 

 an application of the so-called self-boiled 

 lime-sulphur about one month after the 

 blossoms fall to ward off brown rot. For 

 method of making this see Spray Calen- 

 dar or Bulletin 198. 



Towards the end of August or in early 

 September cold, wet weather sometimes 

 requires an extra application to keep off 

 late attacks of scab and sooty fungus on 

 apples. I should use the same mixtures 

 as for the third application. 



A Power Sprayer Po*tei«ing Uteful Feature* 



Thia atrt-aymotor etoos and starte up automatically by moaJiB of the preesure. No safety valvo 

 is required Tho pump only pumps up the pressuro when it etopa itself. 



