PRESIDENTIAL ADDRESS. 539 



ill trying to prevent ragwort from growiug, I cannot help thinking how much 

 the problem would be sbnplified if a plant-breeder would evolve a ragwort 

 with the vigour of the weed and the value of the fodder crop. The great value 

 of new varieties is the diversity that can thus be introduced. Only rarely does 

 a crop find precisely suitable conditions, and only rarely can the conditions bo 

 altered to suit the crop entirely. There is always a gap between what the 

 crop wants and what it can get. It is the realisation of this fact that makes 

 the farmer a chronic grumbler. 



Now, this gap can be bridged to some extent from both ends. The soil 

 conditions can be changed somewhat by the methods already discussed, and the 

 plant requirements can be varied by altering its construction. It is on these 

 lines that new varieties ought to be studied. When a variety is fixed by tho 

 breeder the proper course is to find the conditions to which it is specially 

 suited. This, I think, is much better than trying to put the varieties in a 

 definite order of merit by making a number of tests over the whole county, 

 and then averaging the lot. To begin with, the results of one season rarely 

 agree with those of another over any large area, and in three successive years 

 three different varieties may turn out to be the best — a result which is easily 

 intelligible when put this way, though it looks very odd when set out baldly 

 in a seedsman's catalogue without reference to the fact that the results were 

 obtained in different seasons. Even when an average can be obtained it is not 

 entirely useful. Averages want interpreting for the ordinary farmer, for 

 average conditions never seem to arise on any particular farm. 



It would be a useful thing to multiply simple combined variety and 

 manurial tests, such as are being made by Mr. Dudding on Lord De Saumarez's 

 estate, where varieties run in one direction and a few selected manurial 

 dressings run in the other. 



There seems considerable prospect of increased production by securing better 

 co-ordination between the soil conditions and the variety used, and I am very 

 hopeful of advances in this direction. 



The question arises : How far can the plant-breeder go? Is there any 

 prospect of putting something into the plant that is not there already, or can 

 lie only transfer a property from one variety to another ? Can the physiologist 

 make the plant do more than its normal growth, or do anything beyond ensuring 

 that it shall have the conditions it wants ? 



These questions are difficult to discuss : nothing but the fait accompli being 

 really satisfactory. I shall not deal with the breeding work, but may refer to 

 some of the physiological attempts to stimulate or in some similar way increase 

 plant growth. Many have been made, but so far there is no indication of 

 success. Laboratory evidence is periodically adduced to show that certain 

 substances or electrical or other treatments stimulate plant growth. One of 

 the earliest was manganese sulphate : then came other substances, and in due 

 course radium. All these were tried in crop production, and all failed. Man- 

 ganese salts were tested by Dr. Winifred Brenchley and by Dr. Voelcker ; 

 radium by Mr. Martin H. Sutton. At the present time auximones are under 

 investigation. 



All these things are, of course, perfectly legitimate objects of investigation 

 in the laboratory and experiment station. Some of them may succeed : Mis.s 

 Dudgeon's experiments at Dumfries show that the last word has not yet been 

 said about the effect of the electrical discharge on plants : in any case no man 

 can set limits to the ychievements of science : the impossible of yesterday has 

 often become the commonplace of to-day. Unfortunately the investigators 

 have sometimes let their enthusiasm outrun their discretion, and instead of 

 waiting for properly conducted field trials they have rushed the laboratory 

 results out to the public, sometimes accompanying the account with picturesque 

 multiplication sums showing what would happen if the flower-pot were multi- 

 plied up to an acre, and the acre multiplied up to a million acres. 



If this were done by a business house to push a proprietary article we might 

 safely leave the matter to economic forces and the County Council experts, but 

 the sad thing is that it has been done in the name of Science : tests of the 

 roughest description have been circulated as if they had satisfied the canon.s 

 of scientific criticism, and the farmer is left under the impression that the 



