80 BITTER PIT INVESTIGATION. 



regularity in the size and in the growth and ripening of the fruit. It may be stated 

 generally that for the prevention of Bitter Pit, excess has to be avoided and moderation 

 practised in the various orchard treatments, such as pruning, manuring, and irrigation. 

 The object is to maintain, so far as possible, steady and uniform conditions of growth. 

 13. An instance has been given of the stock influencing the scion in the direction of 

 preventing disease at page 70, and it remains to be seen how far the use of, say, 

 the wild crab apple as a stock might render liable varieties immune to Bitter Pit. 



XVIII. EXPERIMENTS WORTHY OF BEING CONTINUED. 



From the wide scope of this investigation, dealing with every phase in the life and growth of 

 the tree, it was inevitable that a number of experiments could only be initiated, and in the short space 

 of four years over which my engagement extended, could not possibly yield results in every branch 

 of permanent value. Continuity was a factor essential to their success, and I therefore make the 

 suggestion in this, my Fourth Report, that certain of the experiments be continued in the respective 

 States so that the valuable results which they undoubtedly promise may be realized. 



I refer more particularly to those over which the orchardist can exercise control, such as 

 manuring, pruning, stocks, and breeding new varieties. And not only to the orchardist should these 

 results prove of value, but it is necessary to have accurate knowledge so that the great body of teachers 

 and experts engaged in the work of instruction may be able to utilize it. This point of view has been 

 forcibly stated by Dr. Russell in his latest report (1914) on Agricultural Research at the Rothamsted 

 Experiment Station : "Before the expert adviser and the teacher can do their work satisfactorily, 

 it is evident that definite systematic knowledge must be obtained of the subject with which they have 

 to deal. Until this has been done, much of their teaching must be purely conjectural, and may even 

 be unsound. The only safe foundation on which their work can be built up is sound accurate know- 

 ledge gained bv systematic investigation." 



O o t! " 



It has also to be remembered that in these orchard experiments one is to a certain extent at 

 the mercy of the weather. In the past droughty season, for instance, some of the experimental plots 

 did not produce a single apple. Altogether, the time is far too short in which to expect a final result. 



I will therefore make a few remarks on each of these experiments to indicate the direction in 

 which they may prove valuable. 



MANURING. 



The manurial experiments were planned so as to give the maximum of results in a limited time. 

 Sometimes the available trees of the same variety had already been manured, and I could only continue 

 the same manures, with the one difference of using definite quantities in each experiment. Although 

 a summary of results has been given, it is evident that if the experiments were continued, there would 

 be more reliable data from which to draw conclusions, and a greater certainty given to the practice 

 recommended. 



To take the single instance of liming the land, it is important for the orchardist to know the 

 quantities to use and the form in which it is best applied, whether as quicklime or crushed carbonate 

 of lime. The different action they sometimes exhibit upon the soil requires to be cleared up, and there 

 is a considerable difference hi the cost. 



PRUNING. 



Perhaps there is no operation in the orchard requiring more careful attention than that of prun- 

 ing, and yet while there are plenty of books of instruction there is a decided want of experimental 

 evidence extending over a series of years for the methods advocated. 



