During the summer season 1987/88, castor bean plants (Ricinus communis L.) var. IAC-80 growing at the Estação Experimental de Agronomia da Alta Paulista, State of São Paulo, Brazil, showed some symptomus related to boron deficiency. The symptoms included leaf curling, necrosis of terminal bud, small fruit setting and necrosis in the stem. The symptoms occurred after a drought period. Plants were analysed after a new raining period. The nutrient concentrations were higher in plants with deficiency symptoms except for boron. The relations between boron and each one of the macronutrients were lower in plants with symptoms. Soil samples collected under deficient plants were lower in boron than samples collected under normal plants. Based on these informations and on the similarity with boron deficiency symptoms on other plants, it was conclued that the symptoms might be related to boron deficiency.
castor bean; Ricinus communis L.; boron deficiency; drought