16 N.S. ENTOMOLOGICAL SOCIETY. 



a trace of russetting as a result. Bordeaux we have found is the best fungicide and the 

 most lasting one on our list. We have found that poisons used with Bordeaux are re- 

 duced in insect killing value by about 43 per cent and also that poisons will injure the 

 foliage less when used with Bordeaux than with any other fungicide. Bordeaux does 

 not cause curling of the leaves and causes less yellowing than any other fungicide, when 

 combined with a poison, and does not cause dropping of the fruit when used two weeks 

 after the blossoms and later, adding, when a poison is required, lead arsenate. 



Lime and sulphur we have found can more safely be combined with a good com- 

 mercial arsenate of lime than with lead arsenate, because the commercial arsenate of 

 lime contains less than 1 per cent soluble arsenic, whereas the arsenate of lime, resulting 

 from the double decomposition of lead arsenate and lime and sulphur contains about 5 

 per cent soluble arsenic. We have found that lime sulphur reduces the value of arseni- 

 cals used with it by about 19 per cent, thus making it a more efficient carrier for pois- 

 ons than Bordeaux. We ha\e also found that lime and sulphur used 1 to 50 and 1 to 60 

 and even 1 to 75 is practically as efficient as a fungicide, over short periods as 1 to 40. 

 We have found that excessive quantities of any arsenical cannot be used with lime 

 and sulphur without serious leaf yellowing. On account of these various characteris- 

 tics we have found lime and sulphur a good spray to use in the average Nova Scotian 

 orchard for the first three sprays. When fungous diseases are particularly bad it would 

 seem best to use Bordeaux for one or both of the pre-blossom sprays. Where biting 

 insects are bad, it would seem best to use straight arsenate of lead or soluble sulphur 

 and arsenate of lime as a substitute for the particular spray when high insecticidal 

 value is required. 



Sodium sulphide we have found can only be safely combined with arsenate of lime 

 as a poison and then is much safer if a small quantity of slaked lime is added. We 

 have found that soluble sulphur increases the toxicity of poisons used with it by about 

 13 per cent and that it is almost, if not quite, as valuable a fungicide as dilute lime 

 sulphur. Soluble sulphur has in the past, when used with arsenate of lime more than 

 once or twice in a season, resulted in a more or less yellowing of the foliage and leaf 

 drop in most orchards. In spite of this, it has not caused dropping of the fruit even 

 when the leaves were seriously yellowed, to the same extent as lime and sulphur, show- 

 ing that the yellowing caused, although conspicuous, is really less injurious than the 

 curl caused by lime sulphur. On account of its increasing the value of arsenicals used 

 with it, we are recommending sodium sulphide aresenate of lime, as a substitute for 

 lime sulphur arsenate of lime for the first spray, or for the second or third in case a pow- 

 erful insecticide is required for them, but so far we recommend its use only once in a 

 season in our orchard. 



Barium tetra-sulphide like the other sulphides should only be used with arsenate 

 of lime. It comes in powder form and is very convenient to handle but gives more yel- 

 lowing than lime sulphur. When used with arsenate of lime, it reduces the value of the 

 arsenicals used with it by about 16 per cent. It is apparently slightly less efficient as a 

 fungicide than lime sulphur. We have yet to find a place on the spray program where 

 it is superior to all other sprays. 



Lead arsenate regular, double or triple strength is our most rapid killer. This in- 

 sectide is proving an excellent one under the most adverse conditions. It is the safest 

 of arsenical poisons on foliage and in spite of this, we find that repeated applications will 

 result in slight leaf burn and slight yellowing in poorly fertilized orchards. As this 

 spray would only be used where an orchard is threatened with extreme leaf injury or 

 defoliation, the slight injury resulting from this spray would not figure. 



From this you can see the difficulty of devising a spray calendar that will fit all 

 conditions. The number and kind of biting insects present, the susceptibility of the 

 orchard to scab infection, the fertilizing and general health of the trees all influence the 

 spray program; and while we know that enormous improvements have been made by 



