64 CITRUS CULTURE IN CALIFORNIA. 



GUM DISEASE. 



This disease is first detected close to the ground, and also 

 upon the trunk of the tree, and also on the limbs. It is a yel- 

 low gum which forms on the outside of the bark. It is an 

 exudation of the sap of the tree which breaks through the 

 bark and forms a gum. For several years various remedies 

 were tried, but none proved effectual, for how could they; for 

 the disease was not on the outside of the bark, as many did 

 suppose, because they saw the gum running down the trunk. 

 The disease is under the bark, and also will be found to have 

 entered the inner bark, and in bad cases deep into the wood. 



REMEDY. 



Cut away the bark surrounding the place from where the 

 gum is oozing. When this is done, it can be detected where 

 the main affected parts are. Then cut into the wood with a 

 half-moon chisel or gouge, until all the parts from where the 

 gum is oozing is removed ; then leave it stand for a couple of 

 days ; then, if on examination it is found that the gum is still 

 running, cut away more of the wood, until every particle of 

 the disease is taken out. (Generally, if any is left, yellow 

 streaks are seen in the grain of the wood, which are traces of 

 it.) Then leave it alone for one or two days. If, on examina- 

 tion the second day, no more gum is seen, or any trace of it 

 whatever, then it is a sign that all of it has been taken out. 

 The wound must then be covered with some substance, so as 

 to not allow the action of the atmosphere from cracking the 

 wood left exposed, as it may injure the tree. If the disease 

 has gone clean around the tree, then it is too far gone, and 

 there is no cure for it. In such cases it is better to remove the 

 tree and place a healthy one in its place. 



COVERING THE WOUND. 



The simplest of all substances is rubber paint, manufactured 

 by the Pacific Rubber Paint Company, at San Francisco. At 

 least two coats should be given it. This will prevent the 

 wound from cracking, and help it to heal. 



