Resumen
- The present study aimed to establish the preliminary diagnosis and recommendation integrated system (DRIS) norms for the rubber tree clone FX3864 (Hevea brasiliensis) under the conditions of the Colombian Eastern Plains for the elements N, P, K, Ca, Mg, Na, S, Fe, Cu, Zn and B. For this purpose, 77 foliar samples were taken from a 10- to 12-year-old commercial crop. The element ratios that contributed the greatest variance between high- and low- productivity populations were selected for conversion into norms. Of the 132 possible ratios, 66 were selected, with ratios including P/N, N/K and NXCa proving most important. The most limiting nutrients were K and N when deficient and Ca and S when in excess