APPEARANCES MISTAKEN FOR BITTER PIT. 



25 



Then, finally, the Angaston Experimental Committee was appointed to conduct a series of 

 experiments, for the purpose of preventing or eradicating the fungus diseases of fruit-trees. 

 Spraying operations commenced on 20th July, 1891, with a Dobbie's Triple Cyclone nozzle, and 

 the materials used were Ammonio-Copper Carbonate, Eau Celeste, and Bordeaux mixture. 



This was really the beginning of the general practice of spraying fruit-trees in South 

 Australia, and Bitter Pit had existed there many years previously, for in his report of 1886, Mr. 

 Crawford writes — " For several years I have received apples from various parts of the Colony 

 covered with slightly depressed, roundish spots or pits, about one-eighth of an inch in 

 diameter." 



EVIDENCE FROM OTHER COUNTRIES. 



In dealing with evidence from other countries, one must first be satisfied that the Australian 

 Bitter Pit is identical with the disease so-called elsewhere, and in the references to be given 

 there is definite proof that this is the case. In Germany, Sorauer has illustrated and described 

 it in his " Atlas der Pflanzenkrankheiten " and in South Africa, Lounsbury has represented the 

 disease in its natural colours. There is no doubt, therefore, that the same disease is 

 referred to. 



Dr. Paul Sorauer, the well-known author of a standard Text-book on Plant Diseases, writes 

 me as follows, after a perusal of Dr. White's paper : — " I cannot adopt the view of Dr. White. With 

 us the disease appears without the use of any spraying material, and, indeed, in many cases isolated 

 in the fruit pulp, and then without being connected with the epidermis, so that the cause cannot 

 come from the outside." 



Dr. Galloway, Chief of the Bureau of Plant Industry, Washington, writes: — " Now, as to 

 your question about Bitter Pit in relation to arsenate of lead. We have also found the Bitter Pit 

 on trees not sprayed with arsenate of lead. Furthermore, the disease has been known for 

 years in certain districts in the United States before the arsenate of lead was used in the 

 orchards." 



Lounsbury, Chief of Division of Entomology, Union Department of Agriculture, Pretoria, 

 has written several pamphlets on the subject, and closely observed the disease in the orchard. Iti 

 one letter to me, he writes : — " There are many parts of this country where it is still unnecessary 

 to spray apple-trees with any arsenical compound whatever, and, indeed, with anything at all. and 

 yet in many such localities Bitter Pit is very troublesome indeed. I have seen the disease bad in 

 unsprayed gardens and orchards, both in the east and west of the Cape Province, and in the 

 Transvaal." In another letter, he writes : — " That one may cause spotting of apples by chemical 

 agencies is neither new nor surprising. The New York Geneva Station reported on a spot in some 

 marketed apples years ago, which appeared to have been caused by some gas to which the fruit 

 had been subjected. Similar injury was experimentally produced by sulphur fumes. I tried 

 the experiment here, with like results. One might mistake such spots for Bitter Pit on slight 

 acquaintance with the trouble. But our true Bitter Pit has its maximum development on the high 

 plateau of South Africa, far from any source of atmospheric pollution, and utterly independent of 

 any insecticide or fungicide. If arsenic in the soil were the cause, our soils must be terribly 

 poisonous." 



It will be seen that the evidence is all against Bitter Pit being caused by spraying, whether 

 with arsenical or other compounds. 



CHEMICAL EVIDENCE. 



Apples and pears, both healthy and pitted, were submitted for analysis to Mr. I\ K. Scott, 

 Chemist for Agriculture, in order to determine whether arsenic were present or not, and in every 

 instance the results were negative. 



