24 



BITTER PIT INVESTIGATION. 



In the Burnley Gardens a tree of the variety Annie Elizabeth, which is particularly 

 subject to Bitter Pit, was specially reserved, together with others around it, in order to test the 

 theory that spraying with arsenate of lead is the cause of it. This tree was sprayed in June, 1911, 

 with red oil emulsion, but had no spraying of any kind afterwards. The Principal of the School 

 of Horticulture kindly undertook to see that this tree and all the trees surrounding it were not 

 sprayed with anything after the red oil emulsion, and precautions were taken to prevent any 

 arsenical spray reaching the tree from a distance by the agency of the wind. Not only so, but as 

 soon as the fruit had set, about 12th October, a number of clusters were enclosed in white calico 

 bags, thus preventing the access of insects, and the possibility of the arsenical spray being carried 

 to the fruit. 



This particular tree is twelve to thirteen years old, on Northern Spy stock, and growing 

 vigorously. The fruit was picked on 6th March, 1912, and that enclosed in the bags was kept 

 distinct. There were 58 bags altogether, and in nine of these the fruit did not grow. 

 (Fig. 111.) 



It was interesting to observe that the fruit enclosed in the bags grew to the normal size, and 

 occasionally there were faint red streaks on the fruit, but usually the colour had not developed. 

 The fruit was carefully examined, with the following result : — In the bags there were 136 apples 

 altogether, 75 of which were pitted, and 61 clean, 5 of the pitted apples being also " crinkled." 

 On the tree there were 132 apples, 50 being pitted, 81 clean, and 1 with crinkle. Of the apples 

 enclosed in the bags, 55 per cent, were pitted, and on the tree 39 per cent. Thus, a tree was 

 treated in the manner suggested by the propounder of the theory, and in the exposed unsprayed 

 fruits there was actually a less percentage of pitted apples than in the fruits protected by calico 

 bags. 



HISTOEICAL EVIDENCE FROM AUSTRALIA. 



As far back as 1886 Frazer S. Crawford, Inspector under the Fruit Act in South Australia, 

 published a pamphlet, in which " Spotted Apples " were described in such a way as to leave no 

 doubt as to the nature of the disease. In the same pamphlet he gave an analysis of the replies of 

 the leading orchardists to questions concerning " Black Spot " or " Scab " of the apple, and there 

 is not a single reference to spraying. Under the heading of " Remedies Tried," it is stated that 

 one orchardist syringed the trees with kerosene soap. Since we have here a definite date when 

 Bitter Pit was known in several varieties of apples in South Australia (not to mention the statement 

 of the Honorable Thos. Playford, one of the oldest fruit-growers, that he first saw it in 1860), it 

 can be shown that spraying, as an orchard practice, had not been then introduced. I am 

 indebted for the following references to W. Catton Grasby, F.L.S. : — 



In August, 1886, in a report of the meeting of the South Australian Gardeners' Society, 

 held on 3rd July, Mr. F. S. Crawford mentioned that a local maker had constructed a spray nozzle 

 upon the pattern of the cyclone. He considered that this would help in the spraying, but stated 

 " the present difficulty was to secure a cheap and suitable pump for the work. They wanted a 

 light affair, a pump in a bucket, which could be filled with the solution, and carried in the 

 hand." 



In the Garden and Field for December, 1886, Mr. Crawford referred to the cyclone nozzle, 

 stating tha^ he was not in any way the inventor, and incidentally establishing the date of the 

 introduction of spray pumps into South Australia 



In March, 1890, Mr. Crawford read a paper before the first Congress of the Agricultural 

 Bureau of South Australia, in which he recommended spraying with Paris Green and 

 other arsenical compounds. This is the first reference to the use of arsenic in South 

 Australia. 



