404 ANNUAL REPORT OF THE Off. Doc. 



iologists agree that au iuciease in soil teniperatiire is favorable to 

 plant growth. As one of them puts it, "The soil is a great factory 

 that has its production vastly increased as the temperature rises." 



Fifth. There are probably dilferences in the biological or "germ 

 life'' activities taking place in the soil. This is a matter upon 

 which I am not qualified to speak with certainty. But I know that 

 the men who are studying soils find that there are various kinds of 

 micro-organisms inhabiting the soil which have much to do with 

 the. proper functioning of the roots that grow therein. The soil is 

 teeming with countless millions of living organisms which bring 

 about necessary changes of one kind and another in that soil ; with- 

 out them higher vegetation would not grow. Noav the activities of 

 these beneficient oiganisms are dependent on soil conditions and 

 King tells us, in the quotation given above, that tillage induces a 

 strong growth of soil micro-organisms ; that it improves tilth so that 

 soil organisms may spread readily and widely; and that it converts 

 lie root zone into a commodious and sanitary living-place for the 

 soil organisms." 



Sixth. The grass may have a toxic or poisonous effect on apple 

 trees. At the Fiftieth Annual Meeting of the Western New York 

 Horticultural Society the speaker gave an account of a series of plot 

 experiments which seemed to show that grass roots in some way 

 poisoned peach trees growing. The United States Department of 

 Agriculture has published a number of observations and experi- 

 ments to show that different plants growing in the same soil may 

 poison each other. 



I am able to give also the results of a most excellent series of 

 experiments planned and carried out on the "Woburn Experimental 

 Farm in England. These experiments were planned to show the 

 effects of growing trees in grass, the latter to be used as a mulch. 

 The following gives the list of the results of the experiments in 

 question : 



"As to the general effect jjroduced by grass on young apple trees, 

 the results of the last few years have brought forward nothing 

 which can in any way modify our previous conclusions as to the 

 intensely deleterious nature of this effect, and we can only repeat 

 that no ordinary form of ill treatment — including even the cobina- 

 tion of bad planting, growth of weeds and total neglect — is so harm- 

 ful to the trees as growing grass round them. * * * The evidence 

 which we shall bring forward will, we believe, be sufficient to dis- 

 pose of the views that the grass effect is due to the interference with 

 either the food supply, the water supply or the air supply of the 

 tree, and that it must in all probability be attributed to the action 

 of some product, direct or indirect, of grass growth which exercises 

 an actively poisonous effect on the roots of the tree." I do not put 

 forth the statement that grass poisons the apple as one having been 

 proved but I say that it may be so. 



In conclusion, you are w^arned that particular cases do not war- 

 rant general conclusions. The Auchter experiment is in many 

 respects a particular case and the apple grower must bear in mind 

 that under other conditions, his own perhaps, the trees might have 

 behaved very differently. The Auchter orchard was selected as 

 being typical of Western New York conditions and the restilts ob- 

 tained may therefore be regarded as especially applicable t<^ this- 



