54 Pomona College Journal of Economic Botany 



Where pruning is practiced the weak limbs are taken out. The spurs that 

 have dropped their leaves are also cut out, and in this way much of the hold- 

 over wither-tip is removed. All wood that has withered is also taken away. 

 This pruning reduces in a large measure the number of spores left in the 

 grove and hence greatly diminishes the extent of infection." 



In a letter to Mr. Culbertson, Nov. 18, 1909, he states: 



''Under another cover 1 am forwarding to you my bulletin on Wither-tip, 

 also Hume's bulletins on Citrus Troubles and Anthracnose of the Pomelo, 

 and enclosing you a separate on Wither-tip. This you will notice, was printed 

 several years ago. At the present time we lay more stress on pruning, than 

 on the use of fungicides." 



The following article by an unnamed contributor in the California Culti- 

 vator, Dec. 29, 1910, pp. 660-661, may be of interest: 



"Experience so far has taught us that the only true and sure way to cure 

 wither-tip is by thoroughly pruning. Running over and half pruning usually 

 does as much harm as good. When pruning great care should be taken to 

 saw or cut as close to the base or trunk of the tree as possible, and to make 

 smooth cuts and by all means do not leave any projecting stubs. This pre- 

 caution should be carried out to the letter, because diseases from these stubs 

 are almost certain to occur when wither-tip fungus is present. 



Another thing of great importance is cutting the branches close to the 

 tree as the cut surface soon heals over, leaving a nice smooth body ; also 

 if the trees are to be washed, or doctored, it can be executed in one-third of 

 the time, besides it adds beauty to the trees * * * 



In pruning for wither-tip great care should be taken to remove every limb 

 or branch that is diseased, as it is important to get rid of all poisoned 

 branches and prevent the disease from spreading. Wither-tip can be dis- 

 tinguished in various ways — namely, as the limbs or branches on the outside 

 turn dark brown and the outside bark will continue to get darker until 

 they are dormant, while the inside bark near the body of the tree will keep 

 continually falling and the leaves will turn yellow, and in a short time 

 the limbs will be bare. Trees that die from this disease soon become very 

 brittle and rot in a short time. When the trees are taken with wither-tip, 

 if the fruit is on the tree, it can be noticed by the fruit dropping to the 

 ground." 



The combined testimony of these writers seem to show that pruning is a 

 very important factor in handling this disease in Florida. It might be 

 that we should waive the cost of so great a task and get to work in our 

 California orchards, but it can hardly be brought about until the present 

 methods of using Bordeaux Mixture fails and makes it necessary to resort 

 to the more tedious, laborious and costly means. 



orchard practice 



Cultivation. — It has been made very plain by all authorities that a weakened 

 condition in an orchard, under certain conditions is liable to bring on an 

 attack of wither-tip. That this is true cannot be doubted. 



