Ceylon Coffee Soils and Manures: a Report to the Ceylon Coffee Planters' Association

Abstract

THE writer of this report has at least gathered together a large amount of useful information about the coffee plant, coffee soils, and coffee manures. As an agricultural chemist he has, not unnaturally, attributed excessive importance to the composition and condition of the soils in which healthy and diseased coffee trees are found; manures also are indicated as amongst the chief remedial measures. Doubtless, the proper maintenance of the “condition,” as it is technically termed, of coffee soils has been woefully neglected. Indeed, where there is neither rotation nor even alternation of crops the difficulty of securing continued vigour of growth and ample crops of fruit must be considerable, even when soils are rich and seasons favourable. But let any adverse influences, whether of excessive rainfall, or of mechanical and chemical injury to the soil occur, and then the plant is more likely to succumb to the attacks of its enemies, vegetable and animal. Thus wheat straw deprived of adequate supplies of soluble silica becomes more subject to injury from insects and mildew. Other examples might be found of a connection between certain deficiencies in the soil and certain diseases in the plant, but it is unsafe to make a hasty generalisation on this point. In combating the coffee-leaf disease we must first of all devote ourselves to the fungus which is its direct cause. There can be little doubt that calcium sulphide, which proved so efficient a means of destroying the Oidium of the vine will be equally destructive to the Hemileia vastatrix. A mixture of sulphur and quicklime, or a wash made by simply boiling these two materials together, is much less active.