Variation in cashew tree yields in south-east Tanzania and the implication for management of cashew smallholdings
Keywords:Cashew, Yield variation
AbstractIn 2-ha plots of mature cashew (Anacardium occidentale L.) trees in farmers' fields, cashew production showed large variations in relation to local tree density and canopy ground cover ratio (CGCR). Maximum cashew production usually occurred between tree densities equivalent to 40-80 trees ha-1 but at one site where trees were small it occurred at 120 trees ha-1. Below a CGCR of 0.4, cashew production was low and was usually at a maximum between 0.5 and 0.6. Individual tree yields were highly variable and were poorly correlated with density, canopy ground cover area, trunk cross section area, and yields of surrounding trees. In both on-farm and on-station blocks of trees, individual tree yields were highly correlated with their yields in previous years showing that, at the same site, tree yields relative to each other were consistent from year to year. All on-farm sites contained an appreciable proportion of very low-yielding trees. The productivity of smallholder cashew farms may be improved by a combination of selective thinning of poor yielding trees and planting available spaces with improved material.