Pj. Martin et Lj. Kasuga, VARIATION IN CASHEW TREE YIELDS IN SOUTH-EAST TANZANIA AND THE IMPLICATION FOR MANAGEMENT OF CASHEW SMALLHOLDINGS, Tropical agriculture, 72(4), 1995, pp. 261-268
In 2-ha plots of mature cashew (Anacardium occidentale L.) trees in fa
rmers' fields, cashew production showed large variations in relation t
o local tree density and canopy ground cover ratio (CGCR). Maximum cas
hew production usually occurred between tree densities equivalent to 4
0-80 trees hal but at one site where trees were small it occurred at 1
20 trees hal Below a CGCR of 0.4, cashew production was low and was us
ually at a maximum between 0.5 and 0.6. Individual tree yields were hi
ghly variable and were poorly correlated with density, canopy ground c
over 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 th
at, at the same site, tree yields relative to each other were consiste
nt from year to year. All on-farm sites contained an appreciable propo
rtion of very low-yielding trees. The productivity of smallholder cash
ew farms may be improved by a combination of selective thinning of poo
r yielding trees and planting available spaces with improved material.