Choice and Application of Fungicides to Plantation Crops, with Special Reference to Hevea brasiliensis

Abstract

IT is clear from the correspondence of this Institute during the past two to three years that the extent of care sometimes required in the choice and application of a fungicide to plantation crops is not invariably appreciated. The hazards in the latter case do not necessarily include a significant effect on the ecology of the area, but they do sometimes include a serious effect on the visual or technological quality of the plantations' finished product. This difficulty is encountered with an appreciable number of plantation crops, but it is probably particularly acute in the case of Hevea brasiliensis as so many valuable or potentially valuable fungicides are either (a) vulcanizing agents or accelerators of the vulcanization of natural rubber, for example, sulphur, which is used in the control of defoliation due to Oidium hevea ¹, and certain salts of substituted dithiocarbamic acid which are at present under examination for the control of defoliation due to Phytophthora palmivora, or (b) extremely effective catalysts of the oxidative degradation of natural rubber, for example, copper compounds which have been examined in Ceylon² and elsewhere for the control of defoliation due to Phytophthora palmivora.