IQII.] 



Spraying Experiments. 



891 



during the night after the day on which the spraying had 

 been done, though it did not visibly remove any of the wash. 

 On other occasions— later in the season and under different 

 weather conditions— spraying with the wash at the same 

 strength " scorched " the foliage of Cox's Orange Pippin very 

 severely. 



Conclusions. — In the above experiments no opportunity 

 occurred for testing the value of lime-sulphur as a fungicide 

 against apple "scab" or "black spot." As, however, it has 

 been stated, as the result of experiments carried out in the 

 United States, that it "is about as effective" for this purpose 

 as Bordeaux mixture, the lime-sulphur wash may be recom- 

 mended for trial in this country on those varieties of apples 

 whose foliage or fruit will not stand spraying with Bordeaux 

 mixture. The above experiments show that while the foliage 

 of some varieties, e.g. Worcester Pearmain, show no injury 

 when sprayed with a lime-sulphur wash of sp. gr. roi, the 

 foliage of other varieties, e.g. Cox's Orange Pippin, Charles 

 Ross, King of the Pippins, Blenheim Orange, and Besspool 

 (Tower of Glamis) are severely "scorched" by the wash at 

 this strength. For such varieties a lime-sulphur wash of 

 sp. gr. 1*005 should be used when spraying them in June or 

 later — though possibly the "full-strength" wash is safe to 

 use in May. It must not be forgotten, however, that in 

 righting apple "scab" or "black spot" Bordeaux mixture 

 still remains the best fungicide known, and should always be 

 used for this purpose except on those varieties of apples 

 which are liable to "Bordeaux injury." The lime-sulphur 

 wash, as well as the iron sulphide and copper-sulphide washes 

 mentioned above, should only be used at present experi- 

 mentally and on a small scale. 



The experiments noted above give some evidence that the 

 "home-boiled" lime-sulphur wash is efficacious against 

 "powdery mildews." Although the wash has been used at 

 "full strength" (sp. gr. roi) in May on the foliage of apples 

 and gooseberries without causing any injury, it is advisable 

 at present to use the wash at "half-strength " (sp. gr. 1*005) \ 

 later in the season a weaker wash is necessary when used on 

 certain varieties of gooseberries — a point which requires 

 further investigation. 



