4 



BITTER PIT INVESTIGATION. 



CONTENTS — continued. 



PAGE 



XIV. The Skin of the Apple and Pear— 



Stomata and Lenticels . . . . . . . . . . . . . . . . 40 



Corky or Rough Skin . . . . . . . . . . . . . . . . 41 



Sub-epidermis or Hypodermis . . . . . . . . . . . . . . 41 



XV- Respiration of the Apple . . . . . . . . . . . . . . . . . . 42 



XVI. Chemistry of the Apple, Sound and Pitted — 



Growth . . . . . . . . . . . ." . . . . . . . . 46 



Ripening . . . . . . . . . . . . . . . . . . . . 46 



XVII. Analysis of Replies to Questions by Fruit-growers . . , . . . . . . . . . 47 



XVIII. Various causes assigned for Bitter Pit — ■ 



Mechanical Agencies . . . . . . . . . . . . . . . . 58 



Unfavorable conditions of Soil and Climate . . . . . . . . . . . . 59 



Insects . . . . . . . . . . . . . . . . . . . . 59 



Fungi and Bacteria . . . , . . . . . . . . . . . . 61 



XIX. Degeneration of Apple-tree varieties . . . . . . . . . . . . . . 66 



XX. Geographical Distribution of Disease . . . . . . . . . . . . . . 69 



XXI. Bitter Pit and its Contributing Factors — 



Where it originates . . . . . . . . . . . . . . . . 71 



When it originates . . . . . . . . . . . . . . . . 71 



Its occurrence towards the " eye " end . . . . . . . . . . . . 72 



How it originates . . . . . . . . . . . . . . . . . . 73 



Origin of 1 ' Crinkle" .. .. .. .. .. .. 76 



Contributing Factors . . . . . . . . . . . . . . . . 70 



Practical Applications . . . . . . . . . . . . . . . . 77 



Remedial Measures . . . . . . . . . . . . . . 78 



XXII. Experiments with a view to controlling the Disease — 



A. Manurial Experiments— 1. Box Hill, Victoria .. .. .. .. 



2. Bathurst, New South Wales . . . . . . . . 83 



3. Blackwood, South Australia . . . . . . . . 39 



4. Tamar Valley, Tasmania . . . . . . . . 90 



B. Pruning Experiments — 5. Burnley Horticultural Gardens, Victoria . . . . 92 



6. Deepdene, Victoria . . . . . . . . . . 95 



7. Bathurst, New South Wales . . . . . . . . 95 



8. Blackwood, South Australia . . . . . . . . 9$ 



C. Experiments with Stocks — 9. Burnley Horticultural Gardens, Victoria . . . . 99 



10. Blackwood, South Australia . . . . . . . . 100 



D. Cultivation Tests . . . . . . . . . . . . . . jqj 



E. Irrigation Experiments— 11. Bacchus Marsh, Victoria .. .. .. 101 



F. Cold Storage Experiments .. .. .. . .. it ]qi 



G. Miscellaneous . . . . . . . . . . . . 1 1 1 07 



Summary . . . . . . . . . . tt tu 1 1 



Literature directly relating to Bitter Pit . . . . . . . . . , ] j ^ 



General Literature . . . . . . . . . . . . _ < j j » 



Explanation of Plates . . . . . . . . , , . . _ , j ^g 



Appendices — I. General Scheme of Bitter Pit Investigation . . . . . . . . . . l85 



EL Manuring, Pruning, and Stocks . . . , . . . . . t # jg^ 



III. Questions regarding Bitter Pit . . . . . . . , jg^ 



IV. Australian Seedling Apples in relation to Bitter Pit . . . . . . ]gg 



V. Varieties subject to Bitter Pit, at Burnley Horticultural Gardens . . . . . . 191 



