Stein and Branch Canker may result from an irregular flow of sap, and is 

 sometimes caused by the scorching of the bark, local injuries to the trees, 

 as also the attacks of insects and fungi. Canker is a very difficult disease to 

 deal with, and growers should try to prevent it by avoiding, as far as may 

 be practicable, any of the probable causes named in the foregoing remarks. 

 Prevention is better than cure in most cases, but especially so as regards 

 Canker. When the disease does make its appearance it is somewhat 

 difficult to check it, and there are no absolute remedies. All that can 

 be done when the roots are affected is to promptly cut away the diseased 

 parts to such an extent as may be necessary and practicable. The same 

 system must be adopted when the branches are attacked. Should, 

 however, either roots or steins be badly cankered, it will be the wisest 

 plan to destroy the trees, as the chance of curing them is but slight. 



Collar Hot. This is the most destructive and troublesome disease 

 that affects the Citrus family, and often causes serious losses to 

 growers. It also is known as Foot Rot, Gum Disease, and Sore Shin, 

 while in the south of Europe it passes under the name of Mai di 

 Groma. This disease is said to have first made its appearance about 

 fifty years ago in the Orange groves of the Azore Islands. Soon 

 after it spread to the countries bordering the Mediterranean Sea, 

 and since has been a serious evil to European cultivators. It has 

 also been very destructive in the Australasian Colonies, and equally so 

 among the orangeries of California and Florida. The disease is a 

 mysterious one, and it has not been ascertained clearly what is the 

 cause or causes. Though various theories have been propounded, 

 further observation is necessary before we can be positively sure of 

 the cause of this evil. The disease attacks the trees near to the 

 surface either above or below the soil, its first appearance being 

 indicated by the exudation of a few small drops of gum from the 

 bark. These increase in size, and the bark gradually rots away and 

 drops from the stem. Afterwards the surface of the wood becomes 

 affected, and the tree gradually dies away. Soon after the tree has 

 become affected, the foliage begins to have a yellow and sickly 

 appearance, and when this is observed an examination of the base of 

 the stem should be made. Among the theories propounded as to the 

 cause of the disease are want of proper drainage, unsuitable soil,. 

 planting 1 too deep, and allowing water to lie round the stems of the 

 trees. These things are all of great importance to the health and 

 vigour of the trees, but it is doubtful whether any one of them is the 

 real cause of the disease. The most probable cause is sudden and 

 extreme variations of temperature hi the surface soil surrounding the 

 steins, which affect the regular now of sap, and cause contractions 

 and expansions of the bark. As the disease always attacks the lower 

 part of the stem near to the surface of the ground either below or 

 above, the cause certainly seems most likely to be the result of 

 peculiar soil conditions. 



The disease is a very difficult one to deal with, and though, if 

 action is taken at an early stage it may be checked to some extent, 

 yet there is no absolute remedy. The treatment likely to be of 

 service is to earefullv remove the affected bark, and cutting a wav 



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