But of one thing, however, I do feel absolutely certain, and that is, that when the land is well cultivated, manured, and judiciously shaded with good caste trees, leaf disease may be reduced to such a degree that we need not trouble ourselves about it, and I feel equally sure that the most important of all the agents for controlling and limiting the disease is the shade of good caste trees.  And as to the effect of shade upon Hemeleia Vastatrix, I made particular inquiries when visiting estates in 1891 on the slopes of the Nilgiris, and conversing with planters on the subject.  One manager went so far as to say that there was no leaf disease under the shade trees.  Mr. Reilly, of Hillgrove Estate, said there was much less leaf disease under the shade trees.  Another planter of great experience told me that leaf disease begins on the coffee in the open, and then spreads into even the finest trees under shade, but that those are affected in less degree.  “In the end,” he said, “You see the estate all yellow, but with green patches of coffee under the shade trees.”  In short, I found that all the planters I consulted were agreed in saying that there was but a small amount of leaf disease under the shade trees.  The estates on the Nilgiri slopes have been originally all in the open, but latterly shade has been encouraged on some estates, but not to a degree which in Mysore would be called shade.  However, the shade was quite sufficient, as we have seen, to illustrate the important fact that shade can control leaf disease.  And as shade can control leaf disease, I need hardly say that it is of the utmost importance (just as it is as regards Borer), to carefully fill up at once all spots where shade is deficient, because this deficiency encourages leaf disease, and forms a breeding ground for spores to fly into the surrounding coffee.  Open spots here and there may not strike one at first sight as being of much importance, but if they are all added together, the planter will see that they will amount to a considerable area of land, and quite sufficient, at any rate, to inoculate his plantation with leaf disease.

The reader will observe that I have said that leaf disease may be reduced within practically speaking harmless limits if the coffee is judiciously shaded with good caste shade trees, and I would call particular attention to the term good caste trees, because bad caste shade trees will not control leaf disease.  On the contrary, Mr. Graham Anderson informs me that he has seen worse leaf disease under a dense covering of bad shade trees than he has in the open, and he also informs me that, though shade is the backbone of our success in Mysore, he has had more misfortune from all causes when his estate was under the heavy shade of bad caste trees than he has ever had since, though many places are not yet properly covered with the good kind of shade trees which he had planted to take the place of the bad ones he had removed.  I am much indebted to Mr. Graham Anderson for information on the subject of leaf disease, and he has been kind enough to enumerate the following conditions under which leaf disease is liable to occur in the cases of good soils under good shade: