

EXPERIMENTS CONDUCTED WITH A VIEW TO CONTROLLING DISEASE. 31 



The heaviest yield was obtained from a complete manure with lime added, and the lightest from 

 sulphate of potash and sulphate of ammonia, which was practically equal to the unmanured plots. 



The plot treated with sulphate of iron was planted a year later than the others, and that may 

 account for the very small yield. It was not deemed advisable to include this plot in the general 

 summing up of results. 



The least amount of Pit was in the plot with the lightest yield, although it was practically equal 

 to that with lime alone, which had a good average yield. 



The greatest amount of Pit was in the superphosphate and lime plot, which had a yield practically 

 equal to that of lime alone, so that there is not a necessary relation between the total yield and the 

 amount of Pit. It is the size of the fruit which seems to be the determining factor, and when 

 abnormally large it is most subject to it, as shown in the following table : 



TABLE XIV. 



PERCENTAGE OF PIT IN RELATION TO THE DIFFERENT GRADES OR SIXK OK FRUIT 

 IN CLEOPATRAS AT GOVERNMENT EXPERIMENT ORCHARD, ELACKWOOD. 



Grade. Total Yield. Pitted. Per cent. Pitted, 



inches. Ibs. Ibs. 



2 57 f 1-3 

 2J 457 9f 2-1 

 2 1238} 41 3-3 

 2| 1371 70| 5-1 



3 8781 76 8 () 

 31 181.1 31 17-1 

 3i 6i" 4 64-0 



Total 41891 233 5-5 



This is a very interesting and instructive return, showing conclusively that the Pit is developed 

 in a regular and progressive manner, according to the size of the apples on the trees. Starting with 

 a grade of two inches in diameter, the Pit is only 1'3 per cent., but it gradually increases with the 

 increase of grade until in the largest, three and a half inches in diameter, it reaches 64 per cent. 



It is a well-known fact that on a Pit-liable tree the fruits above the average size are most likely 

 to be pitted. It will also be remembered that in the case of the heaviest known apple Dunn's 

 Favourite, weighing 2 Ibs. 2 ozs. the specimen was not only phenomenal in size, but also badly pitted. 

 The average size of Cleopatra apples is 2|-2f inches in diameter, and above that size they are seen to 

 become increasingly liable. 



In recording the results of our experiments, it is a question for consideration whether the number 

 of fruits or the weight of the crop should be taken for determining the amount of Pit. The percentage 

 will be slightly heavier by weight than by number, since the larger apples are almost invariably more 

 subject to Pit than the smaller ones. The fairest mode of presentation would be to give the number 

 of apples affected per hundred, but where large crops and numerous experiments are concerned this 

 is not always an easy matter. The most instructive method would be to give percentages of Pit 

 both by number and weight, and in the Stock Experiments at least an effort will be made to tabulate 

 the results accordingly. 



5. AT MOUNT BARKER ESTATE ORCHARD, WESTERN AUSTRALIA. 



This experiment has been conducted for four years in succession on Cleopatra trees, which are 

 now in their eleventh year from the date of planting. In the past season, however, the special manures 

 were not applied to each plot, since there was some uncertainty as to whether the experiments would be 

 continued. 



