NATIONAL COUNCIL OF HORTICULTURE 17 



simply neutralize toxic principles which may be present in them, and 

 we may be reasonably certain that we are dealing simply with an 

 abundance of plant food in highly available form, placed under ideal 

 conditions for the crop to put itself in touch with it. 



Chairman Manning: Shall we take up the discussion of Professor 

 King's paper? 



Mr. Vaughan: We have so many papers, and the program is pos- 

 sibly going to be so long that we could better defer the discussion 

 until opportunity comes. 



Chairman Manning : Is it the sense of the meeting that the 

 discussion of the papers be postponed to the end of the session? 



Motion to postpone was carried. 



PLANT PATHOLOGY. 

 A. F. WOODS, WASHINGTON, D. C. 



Your secretary has asked me to review as far as possible in ten 

 or fifteen minutes our actual knowledge of plant diseases, the best 

 methods of combating them, the progress that has been made, together 

 with a suggestion or two as to some improvements that may be 

 expected in the future. I have accepted the invitation, knowing fully 

 that I could not in so short a time begin to cover so much ground 

 with a sufficient degree of thoroughness to give an adequate idea even 

 of the most important bearings of pathology on horticulture, but I 

 concluded that the committee must have had in mind that I would 

 use their request as an illustration of the greatest failing, not only in 

 pathological investigation but in the application of methods recom- 

 mended for the control of diseases, namely, too much haste and lack 

 of thoroughness. These are failings incident to work in a new coun- 

 try under great pressure, where the field is large and the workers few. 

 There has been a good measure of economic justification for the mis- 

 takes of the past, and they are teaching us valuable lessons for our 

 guidance in the future. What we need now to do is to study care- 

 fully these successes and failures and determine as accurately as may 

 be possible their causes as a basis for improved practice. The old 

 conditions are rapidly changing. The new times require more careful 

 and intensive methods. 



One-crop farming, too short and unwise crop rotations, improper 

 methods of fertilizing and culture, with destruction of humus and the 

 life and fertility of the soil, careless methods of propagation and seed 

 selection, the use of varieties not adapted to soil and climate, or other 

 limiting conditions, are responsible for loss from diseases in a larger 

 degree than is realized. An orange, a plum, or peach or apple or any 

 other tree or shrub, whose cambium responds to a few warm days in 

 winter or early spring, is not a safe variety to plant in localities 

 where such warm periods occur. Plants of northern range, accus' 

 tomed to respond to lower initial heat stimulus, are thus subject tc 



