Gold, Sport, and Coffee Planting in Mysore / With chapters on coffee planting in Coorg, the Mysore representative assembly, the Indian congress, caste and the Indian silver question, being the 38 years' experiences of a Mysore planter

by Robert H. Elliot

It is time now to turn our attention to the extremely complicated question of the quantity of shade required for the various aspects, gradients, and soils we have to deal with, and let us in the first place begin with some remarks on the effects of aspect as regards heat.

In considering, then, aspect as regards sun and heat, I may observe that it is impossible to exaggerate the importance of taking into account the immense variation in temperature on the different exposures. For the effect that the sun's rays have on certain aspects in heating the soil and drying up the plant, are such as would be extremely difficult to believe, had the facts not been verified by competent observers, and with the aid of the thermometer. And as regards northern and southern slopes in particular, we shall find that the difference between one exposure and the other is just what constitutes the difference between green and dried grass, and between leaves luxuriantly green and leaves dry and withered. And that the first is literally true may be seen by anyone in the months of January and February, for in these months you will see grass on northern aspects green, and, comparatively speaking, fresh, while, even in a valley sheltered from drying winds, the grass on the southern slopes is completely withered. And you will see an equally striking difference in the coffee plants—those on the northern slopes full of health and life, while those on the southern ones are yellow, dried up, and sickly. Even in parts of the district where coffee will not thrive without a considerable amount of shade, you will always find the plants thrive well (with little or even none) on a northern bank, and look much better than on a moderately shaded southern bank. Nor in the nursery is the effect of aspect at all less striking. A nursery on a northern slope will require far less water, and far less shade over the plants, than one with a southern exposure. But the late Mr. MacIvor, superintendent of the Government Cinchona plantations on the Nilgiri hills, has tested the value of northern and southern aspects in a way which accurately judges their respective values. He accordingly tells us that, "The reason why a northern exposure in these latitudes is beneficial is from the fact that it is much more moist during the dry season than a southern aspect, because the sun's declension is southerly during the dry and cloudless season of the year, and thus, on the northern slopes, the rays of the sun do not penetrate and parch the soil. A northern aspect has also the advantage of preserving a much more uniform temperature than a southern aspect, because the excessive radiation and evaporation in the southern slopes greatly reduces the temperature at night, while in the day they are heated to excess by the action of the sun's rays striking the surface nearly at right angles. The practical effects of aspect on the plants are so great that they cannot be overlooked with impunity, and, in order to impress this on the minds of all those who may have the selection of localities for cinchona cultivation, I may mention that the difference of temperature is almost incredible; for example, at this elevation (probably about 7,000 feet) a thermometer laid on the surface of the southern face of a hill exposed to the sun at 3 p.m., will frequently indicate from 130° to 160° Fahr.; the same thermometer, if left in its position, and examined at 6 a.m., will generally be observed to indicate from 30° to 40°, while on a similar slope, if selected with a northern aspect, the thermometer, under the same circumstances, at 3 p.m., will generally indicate from 70° to 80°, and at 6 a.m. from 40° to 50°."

There is, then, about twice as much heat upon a southern as on a northern aspect, and, of course, a corresponding difference as regards the effect of sun and drought on plant and soil, and it is therefore obvious that our shade policy should be governed accordingly.

As regards the comparative heat on western and eastern exposures, Mr. MacIvor does not seem to have made any experiments with the thermometer, but where the slope is at all sharp the rays of the fierce western sun beat strongly into the soil, while it is quite off an easterly slope, of similar gradient, for the whole of the afternoon, and there is an enormous difference perceptible in the temperature. The effect, however, is in some degree counterbalanced by the fact that the soil and the plants on the easterly slope are swept by the withering and desiccating winds which sweep over the arid plains of the interior.

We have seen, then, that the heat is very largely affected by the aspect, but the relative amount of heat and coolness is of course controlled, to a very considerable degree, by the gradient of the land, and just as steep northern slopes will be very cool, and steep eastern slopes moderately so, so will steep southerly and steep westerly gradients be extremely hot. The heat and coolness of the land, then, is constantly varying, not only with the aspect, but with the steepness of the gradients, and both of these points must be taken into consideration in regulating the quantity of shade required; and the reader will therefore see how impossible it is to give more than a general guide towards the quantity of shade required, and all I can undertake to say is that about twice as much shade is required on a southerly as on a northerly slope, that rather more shade is required on a westerly than on an eastern aspect, and that the last named requires less than a southerly aspect.

But this question is further complicated by the varying quality of the soil.

For our soils vary much in the same plantation, and require a greater or less degree of shade accordingly. The lighter and drier soils, of course, require not only more shade, but different kinds of trees, and in the case of such soils jack and cub busree should be freely used, and especially the former.

The quantity and quality of the shade required is also complicated by considerations as regards wind, and, where the soil is exposed to drying east winds, more shade should be put down than would otherwise be necessary, had we only to deal with the drying caused by the sun's heat. And in the case of such lands the shade should consist very largely of jack and other thick foliaged trees, and these should be topped in order to keep them short and bushy, and thus the more able to shield the land from the effects of desiccating winds.

And the whole subject is further complicated by questions of elevation and the varying quantity of rainfall, as the planter is nearer to, or farther from the Western Ghauts, and here I can only say generally, that the nearer you go to the Ghauts the less shade you will require, and the further to the east the more is necessary, but the planter must be guided here by local experience, as it is impossible to write precisely on the subject.

Before quitting this branch of my subject, it may be well to show in a single sentence the overwhelming importance of having well regulated shade of the best kinds. If, then, the shade is excessive, the coffee will not bear well, and if it is deficient or composed of a bad class of trees, the coffee will be certain to suffer from Borer and leaf disease.