Swellings on the Shoots of Cacao Plants Deficient in Copper

Abstract

AN experiment to induce symptoms of micronutrient-element deficiency on cacao grown in sand-culture was undertaken in 1958. The sand and chemicals were purified as recommended by Hewitt¹ and the water was demineralized by passing it through resin columns. The treatments were done in duplicate; a complete set of treatments was randomized within each of two blocks. Seeds were taken from the centre portions of Amelonado cacao pods (where they are more uniform); they were washed and planted directly into the sand, three seeds to a plastic pot. The plants were watered with demineralized water twice a day for one week, after which 500 ml. of nutrient solution was supplied in the mornings and an equal amount of water in the afternoons. Complete overhead shade was given for one month, after which it was reduced to 50 per cent. Plants were harvested 100 days, 204 days and 321 days after sowing.