Desenvolvimento de mudas de Tabebuia chrysotricha em função de substratos e de soluções de fertirrigação

Abstract

The work aimed to study the development of Tabebuia chrysotricha Standl. seedlings in function of different substrate and different fertilization solutions. To compose the substrate it was used fibrous and granulated coconut fiber obtaining the following treatments: S1- 100% fibrous, S2- 60% fibrous and 40% granulated, S3- 40% fibrous and 60% granulated and S4- 100% granulated. The basis fertilization was the same for all treatments and the solutions of fertilization varied in order to obtain solutions with the following electric conductivities: EC1- 1.06 dS m ¹, EC2- 2.12 dS m-¹, EC3- 3.2 dS m-¹ and EC4- 4.25 dS m-¹. The propagative material was sowed directly in plastic containers (120mL) with the respective substrates. The fertilization was received through sub irrigation once a week, until the seedlings reached 20cm of height approximately. The chemical analyses of the substrate (EC and pH), through aqueous extraction method 1:1.5 (1 substrate: 1.5 deionized water), the analyses of aerial part height, stem diameter and pairs true leaves number, as well as the weight of total dry matter, were accomplished each 15 days. In almost every analysis, the substrate with granulated coconut fiber, as well as the smallest EC (1.06 e 2.12 dS m-¹) of fertilization solutions, formed seedlings with higher averages, indicating faster growth. In the conditions of this experiment, the production of T. chrysotricha seedlings was better in granulated coconut fiber substrate and fertilizer solutions with EC of 1.06 dS m-¹, appreciating the estimated characteristics.