ROOTSTOCK EFFECTS ON COCOA IN SABAH, MALAYSIA

Abstract

Twelve seedling cocoa families were evaluated as rootstocks in Sabah, Malaysia using three commercial cocoa clones as scions. The average yield was about 3 t dry cocoa beans ha⁻¹. Yields on pure Scavina rootstock were about 10% above average and those on pure West African Amelonado about 10% below average. However, the effects of rootstock on yield were correlated with those on vigour and there was no effect on the ratio of yield to continuing vegetative growth. Rootstock did not influence bean weight or number of beans per pod or the uniformity of the trees. There was no indication of an interaction between rootstock and scion for any of the traits that were studied. The rootstock effect is considered large enough to warrant its control in critical work, especially field experiments with budded cocoa, but development of high performance scions is a higher priority in cocoa than intensive work with rootstocks.