PRACTICAL APPLICATIONS. 79 



4. The freezing point of the juice of the apple has been determined as from 28 to 29 degrees 



Fahr. Hence, if a uniform temperature is maintained in cold storage of 30 to 32 

 degrees Fahr., the oversea export of apples can be profitably carried out without any 

 risk on the one hand of freezing, or on the other of developing Bitter Pit. When 

 the fruit has first been cooled down to a proper temperature, it is found that subsequent 

 changes of temperature during storage may, with care, be confined within narrow 

 limits. After repeated trials and a careful record kept, temperature has only varied 

 from one to one and a half degrees Fahr. during a period of six weeks, the average 

 time taken for a shipment to reach its destination. 



5. Varieties vary considerably in their susceptibility to Bitter Pit, as some are very liable 



in one district, while fairly free in another. The commercial varieties best suited 

 to the district should be considered on planting, and a suitable site chosen. 



6. Nitrogenous manures in excess or large applications of well-made stable manure are found 



to encourage pitting. Nitrogen can be best supplied by means of green manuring 

 sowing field peas in the autumn and ploughing them under in the spring. The humus 

 thus supplied will assist in retaining soil-moisture and encouraging the steady, as 

 opposed to the spasmodic, growth of the fruit. 



7. Lime will remove sourness in land resulting from the decay of humus, and thus enable 



stable manure and green manures more rapidly to act. Its effect will be largely found 

 in a hastened liberation of nitrogen for the use of the trees ; in a smaller degree it 

 will help to liberate potash and phosphoric acid, the last particularly on ironstone 

 country. Except in exceptional cases, lime will never altogether obviate the need 

 for phosphoric acid, but it may do so for nitrogenous manures. An application every 

 second year is desirable. 



8. If the soil is in good physical condition and well cultivated, manuring should be necessary 



only when the orchard comes into full bearing. Then the necessary phosphoric acid 

 and potash should be supplied every year, the phosphoric acid in the form of super- 

 phosphate of lime and the potash as sulphate of potash. 



9. Low-lying swampy land is known to favour Bitter Pit ; whereas well-drained land, by 



promoting healthy root action and preserving the balance between the supply of 

 crude sap from below and transpiration from above, tends to lessen it. The great 

 regulator in the absorption and emission of water by the plant, including the fruit, 

 is drainage. 



10. The experiments with different methods of pruning under similar conditions on the same 



variety of apple have now reached a stage where the cumulative effects of each may 

 be estimated. The net result is that severe pruning tends to produce a virulent 

 form of Pit, whereas light pruning either reduces Pit or prevents it altogether. 



11. An artificial supply of water, as in irrigation, enables the orchardist to keep his trees 



"going" during the fruiting season when necessary, and thereby preventing a sudden 

 change from dry to wet conditions, which is the best known means of producing Bitter 

 Pit. By preserving uniform moisture conditions and never allowing the tree to flag, 

 the size of the fruit is regulated when properly distributed on the tree, and the develop- 

 ment of Bitter Pit prevented. Water can also be applied at the proper time to develop 

 the fruit-buds for next season. 



12. In order to reduce Bitter Pit to a minimum, it is necessary to have the tree well shaped, 



so as to be equally developed all round, to have a strong framework for carrying the 

 fruit, to prune it so that the fruit is well distributed over the tree and not confined to a 

 few main branches, and to uniformly nourish by suitable manures so that there is 



