Management of covers under Hevea in Sri Lanka

Abstract

Results of two experiments, comparing the effects of leguminous creepers and naturals as ground covers on growth of immature rubber, are discussed. In one experiment the growthof rubber in plots under pure legume covers was better than that under naturals. Applications of extra nitrogen to trees in plots with natural covers improved their growth but the latter was not comparable to that in legume plots. In the pther experiments the increase in growth of rubber with higher levels of fertiliser nitrogen was observed irrespective of the type of cover. Application of phosphate to covers led to better tree girths than where the phosphate was applied on the trees, irrespective of the type of cover grown. These results are discussed in relation to the nitrogen content of rubber eaves, green matter, litter and C/N ratio of the litter of cover.