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1 Noy., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 489 
Horticulture. 
THE CAUSE OF DECAY IN PLANTS, AND THE REMEDY TO 
GIVE TO THEM NEW LIFE. ~ 
By R. R. HARDING, 
Curator Botanic Gardens, Toowoomba. 
Tue primary object of this paper is to direct attention to the results of 
unskilful planting of trees. 1 will endeavour to show that this is very expensive, 
and unsatisfactory in the end. When we consider that it takes only a little 
time longer to plant trees properly, the only excuse that can be given for not 
doing so is that the persons who plant trees or shrubs are afraid to separate 
the roots for fear of killing the plant. It would be, as a matter of fact, much 
better to kill it then than to be disappointed in after years. Such cases are 
numerous in this toivn, and I’ am often asked by residents here, and by others 
in differgnt parts of the colony, what is the reason for their trees looking so 
miserable P 
Before I give a practical illustration of this I will go back to the heading 
of this paper: ‘““The Cause of Decay in Plants.” Decay or disease is the 
antithesis of health, and, as the health of the plant means the correct per- 
formance of its functions, disease may be defined to be an incorrect performance 
of those functions. I believe that of all the various kinds and forms of disease 
to which plants are liable, none are so general or so fatal as those affecting the 
roots. In many, perhaps in most cases, it is extremely difficult to say precisely 
where disease originates and how it is produced. tis only when we see it in 
some of its intense forms of development that we are aware of its existence. 
On the authority of the wisest of men there ig nothing new under the 
sun, yet there are constantly presented to us things that appear, and are to us 
essentially new. Take the position of a tree. Its position may be said to be 
unchangeable ; the soil, subsoil, atmosphere, and climate may be so far 
unvarying as to be also unchangeable. On the other hand, the roots of the 
tree are constantly year by year altering their position, traversing as it were 
the whole surrounding area in quest of food. Moisture algo performs a very 
important part in the nourishment of the tree, and all strata of soil penetrated 
by the roots are not equally full of moisture, so that when the roots pass 
_ through one stratum the tree is well nourished, and on passing through another 
it is less liberally supplied. Atmospheric influences also materially affect the 
tree, and as these vary so the growth varies. Insects, too, do occasional injury 
to trees by eating or poisoning their foliage, hence, as the foliage is 
good or healthy, or the reverse, so is the growth of the tree good or 
bad for that or for succeeding years. The mellow, withered, or fallen 
leaf in early or midsummer is not always a sure indication of a diseased tree, 
indeed it is always more satisfactory to find an evergreen tree of any kind shed 
its leaves freely on agitating the tree, than that they should tenaciously hold by 
the tree after they have become withered. The decay or the dying of lenreet in 
some instances, evidently depends on a want of vigour or on partial rot in the 
roots, but in a great majority of cases it is produced by injudicious planting and 
after cultivation. As an instance of this, [ may state that last September I 
was requested to inspect the avenue of camphors growing in the Royal Agri- 
cultural Show Grounds. For the past two or three years they had looked very 
sick, each year getting worse, and they would eventually die if something 
extraordinary were not soon done to them. Various causes have been assigned 
for the appearance of these trees by those who have expressed their views upon 
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