EXPERIMENTS CONDUCTED WITH A VIEW TO CONTROLLING DISEASE. 69 



(6) Pear trees with grafts from badly affected to Pit-free trees, and vice versa. It sometimes 

 happens that in trees of the same variety and age growing alongside each other and to all appearances 

 similar, the fruit produced by some are pitted, and by others perfectly sound. When this has occurred 

 for a number of years, the question arises : Is there something in the constitution of the tree which 

 enables it to resist Pit? 



Josephine and Winter Nelis varieties of pear tree were found growing at Campbell's Creek 

 fulfilling these conditions. 



The grafting was successfully done in September, 1912 grafts from the Pit-free on to the Pit- 

 producing trees, and the reverse. 



No definite results have yet been obtained, and, unfortunately, in the past season there was no 

 fruit on either of the varieties, owing to the drought. The trees look healthy and promise a good crop 

 for next year. 



14. AT GOVERNMENT EXPERIMENT ORCHARD, SOUTH AUSTRALIA. 



The influence of different stocks on the development of the disease is being thoroughly tested 

 by Mr. Quinn in an elaborate series of experiments, which should yield definite results when the trees 

 come into full bearing. At present, of course, the details simply show their behaviour in the early 

 stages, and their value chiefly lies in enabling a complete record to be given later of the results obtained 

 throughout the life of the tree. 



The stock tests are arranged in three series : 



(1) Northern Spy roots with intermediate stocks. The trees were planted in August, 



1908, and the varieties are given in Table XL., with a summary up to date. 



(2) Intermediate stocks with Paradise, Winter Majetin, and Northern Spy roots. The 



stocks were originally planted in August, 1910, when they contained the dormant 

 buds of Baldwin, Cleopatra, Esopus Spitzenburg, Jonathan, and Shockley worked 

 direct into the stocks. Where, however, an intermediate stock was used, that is 

 double worked. The above varieties were not budded until the middle of February, 

 1911. Only a few bore fruit during the past season, and the highest yield was 11 

 apples. None were pitted when gathered. 



(3) Rome Beauty with Northern Spy roots. This variety was worked direct on to Spy, 



planted in August, 1911, and budded over to Baldwin, Cleopatra, Esopus Spitzen- 

 burg, Jonathan, and Shockley, as in Series 2, in the middle of February, 1912. 

 Only Esopus Spitzenburg and Jonathan bore 4 and 1 apples respectively without 

 Pit when gathered. 



TABLE XL. TESTING THE INFLUENCE OP DIFFERENT STOCKS SEASON 1914-15. 



SERIES 1. NORTHERN SPY ROOTS WITH INTERMEDIATE STOCKS. 



No. Variety. 



1 Baldwin . . 



2 Baldwin . . 



3 Baldwin 



4 Cleopatra 



5 Cleopatra 



6 Cleopatra 



7 Cleopatra (Q.) 



8 Cleopatra (Q.) 



9 Cleopatra (Q.) 



10 Esopus Spitzenburg 



Stocks. No - of 



Fruits. 



Dunn's Favourite on Spy 7 



Rokewood on Spy 1 



Spy 



Dunn's Favourite on Spy 

 Rokewood on Spy 3 



Spy 



Dunn's Favourite on Spy 

 Rokewood on Spy 4 



Spy 



Dunn's Favourite on Spy 67 



Clean. Pitted. 



On Tree. Windfalls. On Tree. Windfall's. 



1 



2 



60 



2 

 4 



7 



1 



1 



