NATIONAL COUNCIL OF HORTICULTURE 39 



very much. I remember some years ago I had a young man interested in 

 plant diseases; he said, "If we had the kind of soil that they have in 



, anybody could grow lettuce; it is not a question of the man, 

 it is a question of the kind of soil." I said, "Do you really think it? 

 Let us send up there and get some." We got half a dozen wheelbar- 

 rows full and put up a bed of lettuce, and it was the worst diseased 

 bed of lettuce we ever had. 



Mr. Pierson : Something that was said along this line started 

 me to my feet. I do not think that I can subscribe to the thought, 

 that the soil is the ne plus ultra, I believe the man behind the gun 

 has more to do with it. Of course we all recognize the fact that the 

 soil is a very important factor; we cannot grow anything good on 

 poor soil, but you must have gray matter behind it. 



I believe on the question of plant diseases, we are paying too 

 much attention to remedies. We should pay more attention to the 

 removal of causes that permit the plant diseases. Take for example 

 black spot, which is so injurious to the rose under glass. You hardly 

 ever hear black spot mentioned in these days, but the question is to 

 find the cause that permitted black spot ; to try to cure a plant that has 

 been infected with black spot, is like trying to cure a man of con- 

 sumption. The thing to do is to start with a young, healthy plant and 

 keep that plant healthy, so I think our object in plant diseases is to 

 look at what produces the cause at first and then remedy it. 



Mr. Vaughan asked about melon diseases in certain districts in 

 Colorado. 



Mr. Pierson: I think in those localities that were mentioned the 

 climatic conditions are such that there are no diseases that interfere 

 with the healthy growth of the melon, and necessarily where the 

 foliage and plant are intact, the fruit must be of high quality, so out- 

 side crops are largely the result of accident we might say, rather, of 

 such locality where the conditions are favorable to such plant growth. 

 Of course, under glass one can have more control of circumstances 

 and look for the causes that produce diseases and obviate them by 

 getting rid of the cause that produces them. 



Professor Van Deman : There is one other thing that has not 

 been touched upon, which I think has a great deal to do with this 

 whole subject, and that is climatology. The climatic conditions very 

 largely control the fungous diseases. We come into the arid regions 

 and they are very free from them; for instance, there are certain 

 fruits that may grow in certain climates almost irrespective of soil. 

 The cherry for example will grow nowhere in the United States as 

 large as on the Pacific coast, especially in Oregon and Washington ; 

 the cherries in' that region are not equalled anywhere in the United 

 States and it is largely a matter of climate. They may be left alone, 

 planted and almost absolutely neglected and yet they grow success- 

 fully because of the peculiarly favorable climatic conditions, and while 

 we are discussing this matter of soil and all those other parts of the 

 subject, we must take into consideration the climate as one of the 

 factors. 



