DRIS norms were calculated as described by Beaufils [10]. The whole population was divided into two sub-groups, namely low yielding and high yielding type taking 20 t ha-1 as cut-off yield. The cut-off yield was positioned in such a way that high yielding sub-population reflected conditions that are deemed desirable. Nutrients deficient in oil palm plantations in India were considered for estimation of DRIS norms. Mean values of selected nutrient expres- sions together with their associated coefficient of variations (CV) and variances were calculated for two populations and presented in Table 1. The mean values of nutrient expressions of high yielding population were ultimately chosen as diagnostic norms. The selection of nutrient ratio expression values with relatively large variance ratio (variance of low yielding population (SA)/variance of high yielding population (SB)) was done.