Agronomía Colombiana

The diagnosis and recommendation integrated system (DRIS) is an efficient method for evaluating the nutritional status of crops and was initially developed for rubber. In Colombia, the size of the rubber crop has grown significantly during the last decade, but recommendations do not yet exist for crop nutrition management at a local level. The aim of the present study wasto determine preliminary DRIS norms for rubber clone RRIM 600 under the conditions found on the Eastern Plains of Colombia. To this end, 78 leaf samples were collected, 19 of which were classified as high-yield, showing production above 2,690 kg ha-1, while the remaining 59 samples were classified as low-yield. The highest variance ratio and the value of R were used as criteria for selecting DRIS norms and were found to present differences, only coinciding for 32 of the studied ratios. The calculation of the DRIS indexes was carried outusing the determined norms; and K was found to be the element that most strongly limited production and showed the greatest probability of exhibiting a response upon exogenous application. Additionally, small quantities of Cu and S can generate imbalances that influence the yield of this clone.