Report on a Visit to Southern India and Java Part I.-The Coffee Industry of Southern India

Abstract

Plantation coffee. In S. India arábica coffee is grown at altitudes of 2, 500-6, 000 ft. with a rainfall of 50-170 ins. The sites are usually sheltered, steep slopes of semi-cleared jungle with a northerly or easterly aspect. Shade is retained because, although it reduces yield, it is a deterrent to leaf disease and borer. As a further deterrent to borer the trees are grown close together 6 ft. × 6 ft., and so produce a dense upper canopy, though losing most of their lower primaries and of course giving a lower yield. There is little pruning. Gormandiser (or sucker) growth is general, in fact 50% of one of the most renowned London marks is grown on gormandiser wood. In soil selection a rich jungle soil carrying a luxuriant vegetation is preferred. Shallowness is desirable so that the trees may have a reduced water supply during the dry months of January to March. This is supposed to increase yield. Coffee in S. India is almost entirely surface feeding, and to avoid root damage cultivation is reduced to a minimum. The author suggests that more use should be made of the envelope fork to incorporate the surface vegetable débris in the soil. The digging of 18 in. trenches in alternate rows and allowing them to fill up with fallen leaves, soil, etc., is a satisfactory method for S. India (but unsuitable for Kenya, where the author's coffee interests lie). These trenches check erosion and the organic matter they contain becomes filled with a mass of feeding roots from the coffee. Spraying with bordeaux against leaf disease is usual and effective. Research work. The research centre is the Mysore Coffee Experimental Farm at Balehonnur. Here it is emphasized that, though spraying with bordeaux will check 4 of the major pests and diseases, the time of application is of the utmost importance to success. Manurial trials in progress since 1926 have been almost barren of results, but data tend to show that sulfate of ammonia is the best of the nitrogenous manures and superphosphate of the phosphatic, while there is nothing to choose between sulfate and muriate of potash. Though experiment plot figures do not justify the application of fertilizers, the value of the latter is apparent when contrasting estates which do and do not use them. In estate practice a decline in yield may be expected after two years' discontinuance of fertilizing practices. Breeding work is concentrating on producing resistance to leaf disease combined with quality and much has already been achieved. Vegetative propagation is by cleft grafting, using waxed paraffin paper covers, from March to July (early S.W. monsoon) with 90% success, in other months with only 25% or less. Hardwood cuttings in the open have rooted to some extent, but subsequent growth has been poor. Green manurial trials are directed to finding a suitable cover for young coffee of sufficient height and density to reduce borer attack.