When coffee is grown without shade, as in Brazil, the soil is exhausted in a relatively short time, and a shift is necessary to a new location. In India, where coffee is being grown for over a century, the soil shows no signs of exhaustion. The plant may weaken due to diverse causes and need replacement, but the soil has retained its fertility and can continue to grow coffee. The reason is not far to seek and is found in the Shade under which coffee is grown.

The depression years and accompanying labour shortage, has forced many a planter to thin out his shade too much, in order to obtain larger crops, or, neglect regulation of the shade altogether; both of these have affected the estates adversely.

The first effect of the shade is to prevent the loss of top soil by erosion which ruined many of the earliest plantings, especially in the MalabarWynaad and the western slopes of Coorg Ghauts. It was not so in Mysore where the practice of growing under shade was adopted by the pioneer planters.

The second benefit conferred by shade is the enrichment of the soil by the leaf, branch and twig mulch from the trees. We must not forget either, that the shade trees afford shelter to innumerable birds, which are not only pleasant to see and many of them to hear, but are incalculable service not only by their droppings, but as insect eaters. Dr. Chokkanna estimates the mulch from the shade trees amounts to about 10,000 lbs. per acre annually in deep shade. The potential value of this mulch is equal to 120 lbs. Nitrogen, 70 lbs. Potash and 20 lbs. Phosphoric acid.

A third benefit is the prevention of any excessive temperature and consequent loss of moisture of the soil. It is reckoned that the difference in temperature between a soil exposed to the Sun, and one under shade in the same area, in day time may amount even to 60° F. A severe drying of the soil affects the plant by stopping the free access of air to the roots; the water supply is decreased and the feeding roots which are near the surface dry up.

Wind is an important drying agent of the soil. Especially the dry East wind of summer depletes the soil of large quantities of water. Wind belts in selected places are the answer. The well-established shade not only protects coffee from the sun's rays but shields it from those parching winds which sweep across the plains and dry up the soil.

Neglecting to provide a shelter against the sun's rays, and some protection for the soil against the denuding effect of tropical rains, can well lead to widespread deterioration of coffee.

In a cool and moist atmosphere the activity of the micro-organisms which break up the fertilizing constituents in the soil to make them available for the plant, is encouraged; and, shade provides this atmosphere. In the higher ranges where frosts occur shade is an important element of protection of the plants.

These multiple benefits from shade fully justified Elliot when he said that the greatest point connected with coffee is shade. He even mentions that with plenty of good shade trees on the land, one can close the plantation gates, and abandon the land, and, as long as cattle were kept out of it, return ten years later, saw down the coffee, grow suckers from the stumps, plant up vacancies, and in four or five years the Estate would be as good as ever, and the land even better. For, it would not have been exhausted by crop, and the fallen leaves from the shade trees, would have enriched the soil, provided, that the trees were of the best kind, but that the same could not be done with bad shade trees.

Now we come to the question of "what kind of trees to plant" and, "how to manage them".

The most popular kinds of shade trees belong to the Ficus family. They are the Cub Busree, the Gonee, the Kurry Busree, Eelee Busree, the Heb Mitlee and the Atti. All these give a good pattern of light and shade and also a good deposit of leaf mulch. They have large spreading branches, and will suit any facing and gradient. The first place amongst these is adjudged to the Mitlee and Cub Busree by common consent.

The Nerul, the Hessan, the Wartee, the Godda, the Tare and the Jak are also widely found. The Nerul (Nerale;Nirol) is a fairly quick grower, is easily established and can be used as a good general standby shade tree. The Tare, deservedly a great favourite in the Tamil country, does not seem to have the same reputation in Mysore.

The Jak with its thick leaves is wholesome and should be used especially in hot facing. Its foliage is sufficiently thick to keep out strong sunlight, but not dense enough to prevent a free circulation of air. But there is an objection to the Jak on account of the attraction the fruit offers to all the stray cattle. If the fruits are removed while still immature and put into the compost pit, or else buried, there would be no danger from the stray cattle. It is also said that Jak helps the spread of Green Bug; but, this is a minor pest in Mysore.

The Malle Gerguttee also called Neer Atti grows to gigantic proportions. It is not commonly planted, but, I have always found it good. A tree looking very much like the Neer Atti is the Nai Nerale. This is also planted sometimes.

We have representatives of the Albizzia family (Leguminosae) in the Bagees: Kal Bage and Hotten Bage, and Albizzia moluccana). The Bage with its thin foliage will suit a northern facing. Albizzia moluccana is a quick grower. It is said that in four or five years these plants planted 30 feet apart will cover the coffee plants completely. This species is not to be found to any great extent in Mysore. It is said that when the tree is well established its roots interfere with those of coffee.

Of the exotics, I shall mention the ubiquitous Silver Oak and the Dadap. The popularity of the former is declining now; but there was a time when it was use exclusively on high elevations. The ease with which it was regulated and the abundance of its mulch, may have accounted for its early popularity; but its narrow spread and the poorness of its mulch in mineral constituents have doomed it as also possibly its too exclusive use at one time.

The Dadap had proved a great blessing. Its quick growth, especially in new clearings, and its fertilizing value, both by the mulch and the root nodules, need only be mentioned regarding its advantages. The idea is prevalent that mature Dadaps are harmful to coffee; but I know from personal experience that this is not so. I can mention certain estates in South Mysore, which give the best returns and they have huge Dadaps growing.

Dr Chokkanna has a very attractive table showing the manurial value of the mulch from nine kinds of shade trees. It can be seen next-door in the Research Department stall in the Exhibition.

The list of shade trees mentioned is far from complete; but it includes all the best species commonly found in Mysore. If one plants a selection from these, one will be sure to have the best for his coffee as regards shade. The selection as a matter of course will have to depend on the latitude, facings, temperature and nature of the soil. Yet, one should be careful to have a mixture of shade trees and not too many of the same fat together.

The shade should be neither too great nor too little. It is generally on the heavy side in Mysore estates. In hot facings and in situation exposed to high winds, a thicker shade is required, while a lighter one suits cool facings. Steep slopes require thicker shade particularly to prevent soil erosion. The planter must be guided by local experience since it is impossible to write precisely on the subject of shade. As a general guide it may be stated that about twice as much shade is required on a southern as on a northern slope; that rather more shade is required on a western than on an eastern aspect; and, that the eastern slope requires less shade than a southern aspect.

The spacing at which shade trees should be planted, or left, when clearing jungle, depends on the area covered by their lateral branches. The aim should be to have the smallest number of trees per acre. If the number is too large, the leaf-deposit from the trees decreases, as they will have practically no lateral branches of any size. For this reason, trees like the Howlige are not suitable for shade, except in the bottom of ravines where they may be planted in order to shade the upper side of ridges. Too many trees standing amidst coffee compete with the latter and affect it adversely.

The height to which shade trees grow deserves consideration. If the height is too low there is the danger of the temperature increase in the atmosphere near the coffee plants; if the shade is too tall the "drip" from the branches will be injurious to the coffee plants. The latter, if it occurs. Will necessitate growing of a light secondary shade to break the fall of droplets from the shade trees.

Shade trees are far from static and they require constant regulation by pruning and topping to maintain the proper shade. Management of shade trees is a work of great importance. It is also one of great difficulty: for example, a person who marks down shade trees for removal as being unwanted, should at the same time have a thorough knowledge of the kinds most worthy of retention. The guiding principle for shade regulation should be an even distribution of light and shade and we can achieve this by treating the main laterals in the same way as we do coffee primates while pruning.

In their early stages of growth it is usual to prune the lower branches of shade trees to prevent interference with the coffee plants. If we are not careful with this pruning we will obtain trees that become too tall in a short time.

It is necessary sometimes to remove a shade tree wholesale. If the shade is excessive the coffee will not crop well; if the shade is deficient or composed of a bad class of trees, the coffee plants will be certain to suffer from stem borer and leaf disease. The cheapest and safest way of removal of unwanted shade trees is by way of ringing the tree and applying an arsenical poison to the wound just below the cambium. The nearer the ground the cut is, the larger the number of suckers that will have to be removed until the tree dies. It is advisable therefore, to make the cut as high as possible.

Before concluding, I must say a word about 'clearings'. Having planted the young shade trees there arises the question of providing shade for them; for, without it their growth will be slow. We require, therefore, some quick growing trees as nurses for the good fat shade trees. In olden days the Charcoal tree (Gorkal) was planted as a nurse for the more desirable trees. The Castor was also used. Nowadays the Dadap is used exclusively and in large numbers. One Dadap to every coffee plant is the rule. These are easily removed after the more desirable trees are ready to take their place.

According to Elliot, young shade trees in clearings should be planted in lines running from East to West, and the trees should be planted so close that they may, in five or six years time, touch each other. The object of this formation is that the declination of the sun is southerly during the clear sky season, a close shadow may be cast from the South to the North, so that the spaces between the lines may have a lateral shade cast on them. When the trees begin to crowd each other, every alternate one should of course be taken out, and this may be repeated a second time if necessary.

Good clearings will make good fields; and good shade will help them to best crops.