Growth of clones of Hevea brasiliensis under growing doses of nitrogen, phosphorus and potassium

Abstract

The aimed of this work was to evaluate the early growth of clones RRIM 600 and PR 255 regarding of Hevea brasiliensis, relationed to increasing doses of nitrogen, phosphorus and potassium. For each clone, a randomized block design experiment was installed. The amount of nitrogen (40, 80 and 160 g plant-¹ of N), phosphorus (50, 100 and 200 g plant-¹ of P2O5) and potassium (40, 80 and 160 g plant-¹ of K2O) were a factorial combined form and were distributed in three blocks, add up to 28 treatments, included the control (00-00-00). The seedlings were transplanted into 18 L pots, filled with a horizon A into a Haplic flat ground with a sandy texture. The fertilizers were weighed, mixed, diluted into the irrigation water and applied in a circular groove created around the plants. The variables analyzed were relative average height (Hr), relative average diameter of the neck (DCr) and total dry matter of the plants (MST). Both clones responded regarding the early growth from the analyzed variables. However, the RRIM 600 clone was more responsive and request regarded with fertility, notably in relation to the application of phosphorus. In the other hand, for both clones, they werei ncreased the quantity of nutrients and, a negative effect was observed for the values of the variables, especially when combined with the highest doses of N, P and K (treatment 160-200-160). The amount of nutrients presented in the 40-100-40 treatment were the most indicated as planting fertilizer for both the RRIM 600 clone and for the PR 255.

Keywords:
Fertilizer recommendation; RRIM 600; PR 255; Rubber tree