26 CITRUS TREES AND THEIR DISEASES 



able in the foliage, your foliage is thin, the leaves are 

 small and a thousand appear upon trees where there 

 should be five hundred ; this is the first symptom of dis- 

 ease. Now the first thing to do after this is apparent, 

 is to take a handful of the soil surrounding the body of 

 your tree, some four or six inches down, put it between 

 your hands and rub it thoroughly. If you can not 

 detect any odor by giving it a quick smell after rub- 

 bing, then you might be safe in saying it is not soil 

 condition. 



Then we can look up our climatic conditions and 

 see what they have been. Very often this last is the 

 starting point of disease, the writer ventures to say 

 that unless remedies are applied to prevent, citrus 

 trees will become affected in larger numbers in the 

 next few years than have ever been seen in Southern 

 California, due to the climatic conditions of 1917. 



You will remember that the early part of 1917 

 was cold, much fog and cloudy weather; immediately 

 upon the change from this condition there followed an 

 intense heat. Following this intense heat we dropped 

 into one of the longest droughts, perhaps, that South- 

 ern California has seen for many years. During this 

 extreme drought, I am safe in saying, there was 

 more disease created among the human family than 

 during any season of my knowledge in California for 

 the past twelve years. There were more people com- 

 plaining of feeling bad, stupid, with coughs and hay 

 fever conditions. For about four months we lived en- 

 tirely upon the electricity in the air without oxygen 

 the foliage lost its color and became a pale yellow. 



