THIRTY-FOURTH FRUIT-GRO^^^RS ' CONVENTION. 



25 



PROFESSOR RAMSEY'S ADDRESS. 



Ladies and Gentlemen: Your honorable Chairman here asked me to 

 prepare a paper also on the walnut industry and the top-grafting of 

 the walnuts. A very short time ago I was down to see Mr. Net? and saw 

 the paper which he had prepared, and saw that he had very fully 

 covered the ground which I shall cover at this time ; and as I was out 

 in the field nearly all the time since then, I decided that I would simply 

 try and discuss and emphasize some of the points which he made here 

 this afternoon, and also probably go a little more fully into the nature 

 of the walnut blight, about which you have all heard more or less, and 

 try, probably, to correct to some extent the impression that has gone 

 abroad that this Avalnut blight has really put most of the old seedling 

 walnut orchards in a very bad condition. That is, that it is a blight 

 which is seriously threatening to do away with the whole industry. 



There is a good deal of truth in that, but the walnut industry I feel 

 sure is going to come out of it all right. It is not in quite as serious 

 a condition as the pear blight industry in the north, though it does 

 resemble that to some extent in this respect, that the disease which 

 afflicts the pear is a bacterial disease. This walnut disease is also a bac- 

 terial disease, but we have this difference : the pear blight endangers not 

 only the crop of the pear tree, but the vitality of the trees, of the 

 orchard, and of the industry itself. The walnut blight, while it does 

 cut down materially the crop in the walnut orchard and in the whole 

 walnut section of Southern California, does not materially decrease 

 the vitality of the tree. 



To some of you who may be unfamiliar with the situation and with 

 the workings of the walnut blight, I will say this, that most of the dead 

 branches which you see in the tops of the old seedling walnut orchards 

 at present are not a result directly, I should almost say indirectly, of 

 walnut blight. That is primarily a result of climatic and soil condi- 

 tions which are rather peculiar some years, and which differ a good 

 deal. The old seedling walnut is very susceptible to changing climatic 

 and soil conditions. If you should have certain periods of cold weather, 

 followed again by warm weather, there is very liable to result a serious 

 die-back of the walnut. In fact, most of the dead twigs which you find 

 scattered through a lot of the old walnut orchards at present in South- 

 ern California, even in some of the larger walnut sections, are due 

 primarily to sudden changes in climate, or to some change in the 

 moisture conditions in the soil, or else to indifferent or no care at all. 



I will say this in reference to the walnut situation this year, that the 

 conditions have been very favorable thus far this spring for the setting 

 of a good crop, and if the weather conditions continue as they have 

 during the past three or four weeks, the prospects are that Southern 

 California will have one of the largest walnut crops in its history. 

 But this does not mean at all that we are getting past this period of 

 •disease ; that this disease is dying out in any measure at all. I want to 

 try to explain to you briefly how this disease is primarily dependent 

 upon climatic conditions. 



As I said before, this walnut blight is a bacterial disease, caused by a 

 minute organism so small that you can place from twenty to twenty- 



