112 



BITTER PIT INVESTIGATION, 



17. Cobb, N. A. Cause of an important Apple Disease. Ibid., VIII., pp. 126 and 221. 1897. 



The woolly-aphis is suggested as a possible cause, and it is also suspected that the disease is transmitted by 

 grafting. 



18. — — Bitter Pit. Ibid., IX., p. 683. 1898. 



No evidence to prove disease caused by fungus. 



19. Letters on the Diseases of Plants — Stigmonosc. Agricultural Gazette, New South Wales, XIV., p. 692, 1903 ; 



and Department of Agriculture, New South Wales— Miscellaneous Publication, No. 666, p. 38. 1904. 



Bitter Pit and other obscure diseases of the apple, probably a kind of Stigmonose. 



20. Cooke, M. C. Fungoid Pests of Cultivated Plants — Apple Brown Spot, p. 118. London, 1906. 



" Surface of the fruit and interior marked with brown spots. Cause unknown." 



21. Cotton, A. D. Bitter Pit of Apples. Kew Bulletin, No. 10, p. 401. 1910. 



Refers to two important communications on the subject by Pole Evans and Lounsbury. 



22. Cbaig, J. A Dry Rot of Apples. Canada Exp. Farms Report for 1896, p. 171. 1897. 



The description and drawing show the disease to be Bitter Pit. 



23. Crawford, F. S. Report on the Fusicladiums, the Codlin Moth, and certain other Fungus and Insect Pests attacking 



Apple and Pear Trees in South Australia, p. 53. Government Printer, Adelaide, 1886. 



Under the heading of " Spotted Apples " this disease is fully described, and the opinion of a fruit-grower is given 

 that it is due to the trees being young and making too much sap when planted in a damp situation. It is 

 also noted that certain varieties are subject to spots when a short crop. 



24. Davies, R. A. Bitter Pit in Cape Apples. Kew Bulletin, No. 4, p. 142. 1907. 



Disease of a purely physiological nature, found on trees grafted on " French Crabs " and other stocks, as well 

 as " Northern Spy." In the Transvaal, natural varieties which reproduce themselves truly are all immune. 



25. Delacroix, G. Maladies des plantes cultivees, Maladies non parasitaires — " Points bruns de la chair des pommes." 



Office des Renseignements Agricoles. Paris, p. 275. 1908. 

 Apparently the first reference to this disease in France. 



26. Despeissis, A. The Handbook of Horticulture and Viticulture of Western Australia — Bitter Pit, p. 506. Government 



Printer, Perth, 1903. 



In Western Australia trees badly affected in damp localities on the plains hardly ever show the disease on well- 

 drained soils and on the gravelly slopes of the Darling Ranges. 



27. Diakonofjf, H. In Russland beobachte Pflan^nkrankheiten. Zeitschr. /. Pflanzenk. XX., Pt. 8, p. 464. 1910. 



Bitter Pit found in various districts of Russia. 



28. Stippigkeit der Aepfel. Ibid., p. 482. 1910. 



The disease is a consequence of too rapid growth of individual groups of cells of the flesh, and wherever the 

 conditions are very favorable to hastening the ripening process, either on the tree or in store, there it occurs. 



29. Elkins, D. Bitter Pit in Apples. The Garden. LXXVL, p. 142. March 23, 1912. 



Reply to letter, giving information as to rainfall, &c. 



30. Eustace, H. J. A Core Decay of Baldwin Apples. New York Agricultural Experiment Station, Geneva. Bull. 235. 



July, 1903. 



Reference to Baldwin Fruit Spot. Conditions which favour its development not the same as those which favour 

 the development of core decay. 



31. Evaks, I. B. P. Bitter Pit of the Apple. Transvaal Department of Agriculture. Technical Bulletin, No. 1. Pretoria 



1909. 



The main factors believed to be responsible for the spotting are excessive transpiration during the day followed 

 by its sudden checking and complete abeyance during the night, when root action is still vigorous owing 

 to the warmness of the soil. The theory is propounded of the bursting of the cells due to too great internal 

 pressure, with the result that the dry and tough Bitter Pit spots are formed. 



32. Ewaet, A. J. On Bitter Pit and the Sensitivity of Apples to Poisons. Proceedings, Royal Society, Victoria, XXIV. 



(N.S.), Pt. II. 1912. 



" On three points, however, it may, I think, be stated with confidence that we are on a solid bedrock of estab- 

 lished fact, namely, that Bitter Pit is, strictly speaking, not a disease at all, but is a symptom of local 

 poisoning produced in the sensitive pulp cells of the apples, that more than one poison may produce it, and 

 that such poisons may be derived from more than one source." 



33. Farmer, J. B. Bitter Pit in Cape Apples. Kew Bulletin, No. 6, p. 250. 1907. 



" All attempts to establish a fungal or bacterial origin for the disease failed. The cells of the affected area are 

 always full of starch, and stand out in this respect in marked contrast to the surrounding healthy tissue. 



