Slow-release and organic fertilizers on early growth of Rangpur lime

Daniel Lucas Magalhães Machado,Cícero Cartaxo De Lucena,Dierlei Dos Santos,Pedro Henrique Monteiro Matarazzo,Tiago Barbosa Struiving,Dalmo Lopes De Siqueira

doi:10.1590/s0034-737x2011000300017

Abstract

Slow-release and organic fertilizers are promising alternatives to conventional fertilizers, as both reduce losses by leaching, volatilization and problems of toxicity and/or salinity to plants. The objective of this work was to evaluate the effect of different rates of the organic fertilizer Humato-Macota® compared with the slow-release fertilizer Osmocote® on the growth and nitrogen content in the dry matter of Rangpur lime. A field experiment was conducted in a factorial completely randomized design with an additional treatment (4 x 4 +1). The first factor consisted of four HumatoMacota® rates (0, 1, 2, and 3%) applied to the substrate; the second factor consisted of the same Humato-Macota® concentrations, but applied as fortnightly foliar sprays; the additional treatment consisted of application of 5 kgm-3 Osmocote® 18-05-09. Means of all growth characteristics (plant height, total dry matter, root/shoot ratio and leaf area) and the potential quantum yield of photosystem II (Fv/Fm) were higher when plants were fertilized with the slow-release fertilizer. The organic fertilizer applied alone did not meet the N requirement of Rangpur lime.

Highlights

Citrus containerized nursery production is a technology that is still being refined (Pereira & Carvalho, 2006)
Seed lots of Rangpur lime were obtained from the Citrus Collection of the Setor de Fruticultura - Universidade Federal de Viçosa (UFV)
Application of the organic fertilizer to substrate and supplementation via foliar sprays had no significant effect on seedling height, unless the concentrations of fertilizer in the substrate were combined with concentration of 2% applied as foliar sprays

Summary

Introduction

Citrus containerized nursery production is a technology that is still being refined (Pereira & Carvalho, 2006). Seedling growth in polytubes can be influenced by fertility of substrate, supplementation with side dressing and/or foliar fertilization is usually required (Decarlos Neto et al 2002; Scivittaro et al, 2004). Split application is important, to avoid nutrient leaching, mainly N and K, due to continuous irrigation and the small size of containers (Prado et al, 2008). Studies on the effects of fertilization on growth of citrus rootstocks have shown that nitrogen, required in large amounts and used in key metabolic processes in plants, is a critical element to the process. Because of its high susceptibility to loss, nitrogen should be supplied gradually to plants, in split applications of soluble sources (Decarlos Neto et al, 2002)

Objectives

Methods

Results