EXPERIMENTS WITH A VIEW TO CONTROLLING THE DISEASE, 



107 



G. — MISCELLANEOUS. 

 Kinging or Cincturing. 

 Now that so much attention is being directed to Bitter Pit, orchardists themselves are 

 experimenting in various ways. The theory is very generally held that it is due to an overflow of 

 sap, and an evident means of reducing this is to cincture or ring the trunk or branches of the tree. 

 A New South Wales grower has observed a decided improvement during the past season as a result 

 of twisting several turns of wire round the trunk, especially in the Northern Spy variety, which is 

 particularly liable to Bitter Pit. He asserts that there has been a better setting of fruit and more 

 even ripening. Others have tried it without any apparent effect, but a single season cannot give 

 a conclusive test, and in neither case has a definite comparison been made between a cinctured and 

 a normal branch on the same tree. It must be remembered, too, that the result will depend on the 

 particular stage of growth of the tree, as it is generally considered to be most effective on 

 very vigorous shoots, so that the wound may be quickly healed or the compression readily 

 overcome. 



When a branch is constricted with a ring of wire, the growth of the wood is altered by the 

 compression of the fibres. Afterwards, the wire is enveloped by the new growth, the outer layers 

 are ruptured, and a soft wood is produced. In the vicinity of the wire a black discoloration may 

 be observed, due to the chemical combination of tannic acid with the iron. It is the new wood 

 formed as a result of the compression which constitutes the principal conducting tissue for the 

 upper portion of the branch. This operation is generally considered to cause an early death of the 

 branch, and the experiment will be tried simply to test the effect of the earlier ripening of the fruit 

 on the development of Bitter Pit. 



A tree of the Annie Elizabeth variety has been selected, with suitable spreading branches, 

 and the ringing will be performed on different branches of the same tree in June, July, August, 

 and September, and the wire removed after the fruit is picked. A tree of the same variety will be. 

 cinctured, and the experiment carried out on similar lines. 



In the Queensland Agricultural Journal for May, 1912, it is noted that " Experiments made 

 at the Experimental Station at Bologna (Italy) have shown that by removing the bark in rings 

 from the branches of peach trees the fruiting is greatly encouraged, and the fruit is finer and ripens 

 more quickly than those of trees not so treated. The tree is not injured by this operation, and the 

 fruit is even more firmly attached to the branches." Mr. Pescott also informs me that he very 

 successfully " ringed " peach trees ten years ago, the ringing of each limb with fencing wire giving 

 excellent fruiting growths and fruit as well. The cincturing of currant vines is likewise regularly 

 practised, but it remains to be seen how far this operation will affect the development of Bitter 

 Pit. 



Bending op Branches or Leaving the Laterals Unpruned. 



When shoots are in their natural position, and more or less vertical, the water supply is mainly 

 directed towards the buds near the apex, but, when the shoot is bent and an arch formed, the 

 highest point of the arch will receive the greatest amount of nutritive material. The under 

 surface of such a bent shoot is thrown into folds and wrinkles, because the outer tissues are 

 compressed into a smaller space. This lateral compression causes the outer tissues to split away 

 from the internal wood, and a layer of young wood is formed, rich in starch. The tension of the 

 upper surface causes the cells to stretch and become narrower, so that the flow of sap is diminished 

 towards the apex. The result is that the bending of the shoot interferes with the ascending and 

 descending currents. Above the bend there is an accumulation of formative material, and the 

 buds there are most likely to develop into flower-buds. Below the bend the buds receive a more 

 liberal supply of water, and develop into leafy shoots. 



