486 MINNESOTA STATE HORTICULTURAL SOCIETY. 



Mr. Harris: Some of us professors disagree a good deal on that 

 subject. One professor says it generally occurs when the weather 

 is unfavorable. I am the professor who lays it to that. It may be 

 a fungus that causes it, but all the same when the conditions are 

 right for perfect pollenization your plum starts off naturally and is 

 going to ripen; that plum pocket is not going to come. When they 

 blossomed this year, the weather was warm. When we have some 

 cold weather when they are about to blossom or have a little frost 

 about that time, lots of pockets come on the Cheney. You get the 

 blossom properly poUenized, and I do not think you will be troubled 

 with plum pockets. 



Mr. Lord: I don't know, but I don't believe pollenization has any- 

 thing to do with it* 



Mr. Elliot: Doctors disagree. 



Mr. Lord: I believe I have written and said more on that subject 

 than any other man in the Northwest, and I confess I don't know 

 much about it. (Laughter.) If pollenization has anything to do 

 with it, my experience is that there would be no growth at all if 

 there is a lack of pollenization. My theorj' is that it is simply occa- 

 sioned by cold weather or wet weather at about the time the plums 

 form, when they are about the size of a kernel of wheat, but I confess 

 I cannot prove it. 



Mr. Elliot: I should like to hear from Prof. Green on the subject. 



Prof. Green: I do not want to say anjthing about this. I think 

 in the spring of the year when we have the plum pockets and exam- 

 ine them right along until the pockets are nicely developed, you 

 would agree with me that it was formed by a fungus. I think I 

 could convince you There seems to be no doubt but what it win- 

 ters over in the tree, but, of course, the external conditions have a 

 good deal of influence upon the fungus. We have wheat rust more 

 or less every year, but sometimes people say it is the warm weather 

 that brings it on. In one sense it does bring it on, in another it does 

 not. If the rust is there, it develops more rapidly in warm weather. 

 When the conditions are adverse to the growth of the plum pocket 

 — and by such conditions I mean the strong growth of the tree, a 

 healthy, vigorous growth — I think we are not so liable to have the 

 plum pockets. I have strongly made up iny mind that it is formed 

 by a fungus. 



Mr. Harris: I have not denied that it was a fungus, but if it was 

 properly pollenized the fungus could not get there. It may attack 

 the most vigorous trees. 



Prof. Green: It winters over in the tree. 



Mr. Harris: It winters over; if it were not for those conditions 

 you would have no pockets. 



Mr. Elliot: Would spraying with any of the different solutions 

 have any effect on the fungus? 



Prof. Green: I do not think so, but you cut the trees back and 

 burn them, that is better. We may gain a little by spraying with the 

 Bordeaux mixture, but I think that is not much. 



Mr. Cutts: Would not high cultivation be a preventative? 



Prof. Green: Well, I don't know. I never saw it so bad as I did at 

 the Farm. 



