GROWTH, PHYSIOLOGY AND YIELD OF FORMOSA 'PAPAYA' CULTIVATED UNDER DIFFERENT DOSES OF COATED AND CONVENTIONAL UREA

Gabriel Barbosa Da Silva Júnior,Adriel Moura Silva,Ítalo Herbert Lucena Cavalcante,Francisca Gislene Albano,Eduardo Monteiro Santos

doi:10.1590/1983-21252016v29n305rc

Abstract

ABSTRACT Mineral fertilizer management is one of the most important agronomic techniques applied in papaya cultivation, which generally extracts large amounts of nutrients from soil, especially nitrogen. This study aimed to assess the phytotechnical and physiological attributes and yield of "Formosa‟ papaya hybrid Caliman 01 as a function of different doses of coated and conventional urea in the region of Bom Jesus - PI, Brazil. The treatments were arranged in a factorial scheme (2 × 4) and distributed in a randomized block design with four replications, corresponding to 2 nitrogen sources (coated urea, 43% of N; and conventional urea, 45% of N) and 4 doses nitrogen (350, 440, 530 and 620 g per plant). The N doses used corresponded to 80, 100, 120 and 140% of the nitrogen fertilization. It was used six plants per plot with two row borders, totaling 192 plants cultivated in the field. It was assessed the intercepted photosynthetically active radiation (int.PAR), radiation interception efficiency (PAREff.), leaf area index (LAI), plant height, stem diameter and yield. The coated urea promotes a higher growth and yield of "Formosa‟ papaya compared to the conventional urea. The application of 1.0 g of coated N promotes the production of 2.87 g of fruit per hectare while the application of 1.0 g of conventional N produces only 1.89 g of fruit per hectare, showing that the source of polymerized N increases the use efficiency of N applied to soil.

Highlights

Papaya (Carica papaya L.) is an herbaceous plant, typically found in tropical areas, with fast and frequent production throughout the year
Mineral fertilizer management is one of the most important agronomic techniques applied in papaya cultivation, which generally extracts large amounts of nutrients from soil, especially nitrogen, which is the nutrient required in larger quantities throughout the crop cycle (MARINHO et al, 2010)
It has studied the use of nitrogen fertilizers of controlled release, which constitute inputs whose granules are protected with a layer composed of mineral additives and polymers, favoring gradually the nitrogen supply in the soil solution and, improving its use efficiency by plants throughout the cultivation (GRANT et al, 2012)

Summary

Introduction

Papaya (Carica papaya L.) is an herbaceous plant, typically found in tropical areas, with fast and frequent production throughout the year. Mineral fertilizer management is one of the most important agronomic techniques applied in papaya cultivation, which generally extracts large amounts of nutrients from soil, especially nitrogen, which is the nutrient required in larger quantities throughout the crop cycle (MARINHO et al, 2010). It is used different N sources for papaya nitrogen fertilization, such as ammonium nitrate, ammonium sulfate, and most commonly, the urea, as observed in studies developed by Santos et al (2014) and Santos et al (2016). It has studied the use of nitrogen fertilizers of controlled release, which constitute inputs whose granules are protected with a layer composed of mineral additives and polymers, favoring gradually the nitrogen supply in the soil solution and, improving its use efficiency by plants throughout the cultivation (GRANT et al, 2012)

Objectives

Methods

Results