BITTER PIT INVESTIGATION. 



FOURTH REPORT. 



CONTENTS. 



PAGE 



Introduction ...... . ...... 5 



I. Development of Bitter Pit after apples are gathered X-Ray treatment . . 6 



II. Bio-chemical Researches on Bitter Pit .... 7 



III. Liable and Non-liable Varieties compared and contrasted . . 15 



Chemical Composition of half -grown and ripe Apples of the Cleopatra and Yates varieties 16 



Composition of Ash of the Juice and Solids of Cleopatra and Yates varieties . . 18 



Composition of Liable and Non-liable Varieties from different States . . . . . . 19 



Composition of the Ash of two and three year-old wood of Cleopatra and Yates . . 22 



Composition of the Dried Skins of several varieties of Apples .... 23 



Comparison of the rate and amount of Growth between Cleopatra and Yates Apples . . 24 



Relation between the nature of the Leaf and Bitter Pit .... 25 



IV. The Nature of the Variety Predisposition and Immunity ...... 26 



V. Laterals in their relation to Bitter Pit ...... .... 28 



VI. Effect of Ringing and Fracturing the Branches 



Summary . . . . . . . . . . . . 29 



"Ringed" Pear Trees 29 



VII. The effect of dry and saturated moist air on detached and growing apples 30 



VIII. The Influence of Shelter on the Development of Pit .. 31 

 IX. Old Apple acd Pear trees in their relation to Bitter Pit 



X. The Prevalence of Bitter Pit during Season 1914-15 and its relation to the Weather . . . . 33 



Large Apples . . . . . . . . . . . 34 



Rainfall 34 



XI. Record of Results in relation to Bitter Pit for four years in succession . . . . . . 36 



XII. The Practical Experience of the Orchardist 37 



The Cultivation of the Apple from Planting to Fruit-bearing . . 37 



XIII. The Influence of the Soil on Bitter Pit 41 



XIV. Experiments conducted under natural conditions with a view to controlling the Disease . . 43 



A. Manurial Experiments 1. Box Hill. Victoria .... 44 



2. Bathurat, New South Wales 45 



3. Stanthorpe, Queensland . . . . . . . . . . 50 



4. Blackwood, South Australia . . . . . . . . 62 



5. Mount Barker Estate, Western Australia . . . . 63 

 The Influence of Fertilizers on Bitter Pit 57 



