Levels of NPK on nursery of Hevea spp on the development of plants ready for grafting in a sandy clay loamy yellow latosol, in Mosqueiro Island - PA, Brazil

Abstract

With the purpose of determining the most adequate levels of nitrogen, phosphorus and potassium for the production of plants ready for grafting in nursery, a trial was carried out in a sandy clay loamy yellow Latosol in Mosqueiro Island-PA, Brazil. It was used a randomized block design with two replications following a factorial design of 33. The levels applied were of 0-2.1-4.2 g/plant of N; 0-3-5-7-0 g/plant of P2O5; 0-1.4-2.8 g/plant of K2O and a permanent level of 0.8 g/plant of MgO, the sources applied were, respectively, ammonium sulfate, triple superphosphate, potassium chloride and magnesium sulfate. The results were abtained two-hundred and twenty days after the beginning of the trial, the following evaluations were made: chemical analysis of soil and leaves, plants height, stem diameter, dry matter weight of aerial parts and plant ready for grafting. Based on the overall results od the study it was concluded that the adequate levels were 330 kg/ha (4.6 g/plant) of N; 340 kg/ha (4.8 g/plant) of P2O5 and 190 kg/ha (2.7 g/plant) of K(2)0, together with the permanent level of 60 kg/ha (0.8 g/plant) of MgO, producing a rate of profit of eighty-seven percent of plant ready for grafting.