PLANT HYGIENE. 



75 



like to investigate, but where private resources fail. There is con- 

 siderable evidence that plants occasionally do absorb some substance 

 which appears to be toxic to certain diseases. Cultivators, however, 

 should wait for unimpeachable evidence that any substance recom- 

 mended for this purpose really is of use and that the utility is not 

 counterbalanced by injurious qualities, before investing too heavily. 

 Try samples by all means, but see to it that the plants, soil, and other 

 conditions are really representative and make exact comparisons. 



My purpose now is rather to induce cultivators to adopt every 

 possible method of making plants self -resistant by hygienic means. The 

 soil and climate have more to do with immunity from disease than 

 one often recognizes. The fact that one first-rate investigator is very 

 emphatic in his statements and advice, and another equally recognized 

 authority says the results of his contemporary worker require con- 

 firmation by independent scientists indicates a chaotic state. The 

 unfortunate result is that the most fluent speaker, if he has an attractive, 

 magnetic influence, w^ill obtain the greatest following, quite independent 

 of the soundness of his advice or otherw^ise. 



When carnations or chrysanthemums have been propagated by 

 amateurs, one frequently finds a plant looking very unhealthy, and often 

 dying altogether, ow^ng to structural imperfections, near the base. This 

 is because, when propagating, a flowering shoot had been included 

 among those selected. Such shoots fail to produce vigorous plants, and 

 the failure is usually just before flowering, owing to the severe strain 

 then put upon the conducting and supporting tissues. The remedy is 

 obvious. 



An imperfect union of bud or graft on a stock not infrequently causes 

 trouble when full fruition is expected. Even the most perfect union 

 of a scion on a stock gives a very different connection from the natural 

 one, and it is certainly not sufficient that the scion just "takes." 

 Structural imperfections may be due to injury caused by disease or 

 a wound. Eemoving a narrow ring of tissue, extending to the cambium, 

 from fruit trees is an intentional wound causing an imperfection which 

 will arrest vegetative grow^th and induce the tree to flower and fruit 

 abundantly for a short time, but is often followed by a dying state. 

 This is only justifiable when old trees are to be destroyed within a 

 year or two. The first apparent effects are much the same as, but 

 more decisive than, root pruning; but whereas root pruning, judiciously 

 done, results m considerable permanent improvement, ringing fre- 

 quently has disastrous ultimate effects. Knowledge is power, and it 

 is well to record the fact that one has known an unfruitful old planta- 

 tion worked up and offered for sale in an apparently greatly improved 

 state. The chief operation was ringing of the trees just under the 

 surface soil. Our laws are framed on the principle that the buyer 

 must beware, but such a practice is a moral, if not a legal, fraud. 



Adverse climatic conditions often make it almost impossible to 

 grow certain plants in a particular district or aspect, and this fact is 

 so obvious that it is needless to enlarge upon it. An occasional prime 



