EXPERIMENTS CONDUCTED WITH A VIEW TO CONTROLLING DISEASE. 59 



ence. At Box Hill and Bathurst there is less Pit in the manured plots, although at Bathurst, where 

 limestone has been added to the manure, Pit is increased. At Stanthorpe and Mt. Barker there is 

 decidedly less in the unmanured plots, so we are forced to the conclusion that in the case of Pit, as in 

 that of the yield, the effect of the manure is modified by the accompanying conditions. In the Western 

 Australian experiments for the past season, green manuring with peas gave the lowest percentage of 

 Pit. Since humus is the best regulator of moisture, and therefore of prime importance in preventing 

 violent vicissitudes, the loss from Pit would probably be much reduced if the practice of green manuring 

 were generally adopted. It is especially important, of course, in non-irrigated orchards. 



B. PRUNING EXPERIMENTS. 



Of all the operations of the orchard that of pruning seems to have the most direct effect upon 

 the development of Bitter Pit. It can increase or diminish the crop ; it can determine its distribution 

 upon the tree ; and to a certain extent it can secure an average-sized fruit. No fact has been more 

 clearly established in practice than this : when there is a good average crop, with the fruit generally 

 of normal size and well distributed over the tree, the conditions are least favourable for pitting. It 

 is in the ready response which the well-nourished tree makes to judicious pruning that the possibility 

 of controlling this disease mainly lies. And this pruning has to be attended to, not by fits and starts, 

 but from the time of planting right through the period of bearing. Increased vigour and luxuriant 

 growth are not the only objects to be aimed at, but the distribution of the fruit upon the tree has to 

 be so arranged that each receives its due share of sun and shade, of air and nourishment. 



LONG AND SHORT STEMMED APPLE TREES. 



On pruning the tree in its early stages, the height of the trunk as well as the shape of the tree 

 has to be considered. 



The apple may be grown on Paradise stock as bushes or dwarfs, or as orchard standards with 

 a single upright stem of varying height supporting the head. 



The British and Continental type of "standard" apple tree with a stem up to five or six feet 

 in height does not suit our sunny Australian conditions, and is seldom, if ever, seen in commercial 

 orchards. 



The "standard" apple trees shown in Fig. 54, consisting of Northern Spy and Winter Majetin, 

 are growing at Wandin, Victoria, and were planted by Sir E. Holroyd, in June, 1885. They were 

 yearling trees when planted, and not pruned, but trained up to about six feet, and from twelve to 

 thirteen branches are given off irregularly from the upper end of the trunk. Both varieties bore 

 good crops, and the Northern Spy fruit was of good quality and colour, but in recent years only a few 

 apples were produced of poor quality. 



There is a difference of opinion as to the best height of trunk for apple trees, but I have observed 

 that short-stemmed trees make the best growth and produce abundance of fruit. The shorter the butt 

 the better the tree, other things being equal, for picking the fruit, pruning the branches, protecting 

 the fruit from wind and the tree trunk from the action of the sun. In long-stemmed trees the scalding 

 of the bark causes it to split and peel off, with the result that the wood dies. The scalding of the stem 

 retards growth and ultimately shortens the life of the tree. Wherever relatively long-stemmed apple 

 trees occur, especially Rome Beauty and Jonathan, I find them nearly always weak, compared with 

 short-stemmed trees of the same variety grown hi the same orchard. The stem should be at least a 

 foot or fifteen inches in height, and ploughing can be done quite close to the tree without interfering 

 with the branches. The short stem will enable a greater amount of sap from the roots to reach the 

 leaves in a given time, and the equal diffusion of the sap throughout the entire extent of the branches 

 will tend to promote uniform and regular growth. 



