Nine (9) sites with different growing conditions used in the Regional Testing of Promising Coconut Hybrids and Cultivars in the Philippines or MULTILOC Project (1985‑1996) was subjected to the Crop Fertilizer Use Efficiency (CFE) Analysis. Two CFE indices were used CFEn = nut yield/kg fertilizer applied (per tree) and CFE X = kg copra yield kg fertilizers applied (per tree).

To a great extent, crop fertilizer use efficiency (CFE) of superior hybrids grown in similar environments and appied with same moderate rates offertilizers have higher efficiency of converting the appliedfertilizers to economic yield, nuts or copra (measured in terms of CFEn and CFEc) compared to tall varielies tested in all MULTILOC sites (dry, intermediate and wet growing zone) at n ine years ftom field‑planting (FP). The CFEs, CFEn (nut‑based) at nine sites clearly differed in ternu of the first (best) five entries with highest CFE values. Explanation for this observation deserves further study, looking into the relationship of hybrid vigour (heterosis), crop morphology, physiology and yield.

Among the eleven (11) hybrid crosses, in terms of CFEn and CFEc, some of those which demonstrated wide suitabilityftom intermediate to wet growing conditions and environments, are: MRD x BAY, MRD x TAG, MRD x HJT, MRD x PJT, MYD x WAT The hybrid TAC x BAO dernonstrated impressive CFEs in Mindanao. Although most tall cultivars (Baybay, Laguna, Tagnanan, Mulanay, Loong, Lapasan and Hijo) at nine years from FP have still low value of CFEs compared to most hybrid crosses, with time (at leastfifteen years or more (full‑bearing stage), the CFEs of these talls is likely to be higher and closer to superior hybrids.

The CFE analysis (index), either as CFEn (nut­based) or CFEc (copra‑based) strongly appears to be a practical tool in identifying or screening hybrids and cultivars of coconut grown in different agro‑climatic conditions. It directly indicates the yield (nuts or copra) per kg of fertilizer applied or invested over a period of time.