Nitrogen sources on yield, mineral nutrition and bromatology of Cyclanthera pedate

Samuel V Valadares,Ernane R Martins,Candido A Costa,Luiz A Fernandes,Rafael V Valadares

doi:10.1590/s0102-053620200112

Abstract

ABSTRACT Caygua fruits (Cyclanthera pedata) are used both in cooking and for medicinal purposes. However, few studies on this species, considered a non-conventional vegetable, can be found in literature. This study aimed to assess the responses of caygua crop to green manure and mineral nitrogen fertilization, in relation to marketable fruit productivity, nutrient content in leaves and fruits and bromatological composition. The study was carried out in a randomized block design with four treatments and five replicates: 1) control (without nitrogen); 2) 60 kg ha-1 nitrogen (urea form); 3) green manuring using Cajanus cajans and 4) green manuring using Crotalaria juncea. The plots consisted of three caygua lines with four plants per line (spacing 2x1 m). In the treatments using green manure, three lines of these respective legumes were cultivated. We evaluated marketable fruit productivity, nutrient contents in fruits and leaves and bromatological composition of the fruits. Production of caygua fruits was higher in the treatment consisting of urea application (23.6 t ha-1), followed by Crotalaria juncea (15.6 t ha-1), Cajanus cajans (14.8 t ha-1) and control (9.2 t ha-1). Treatments did not influence the nutrient contents in fruits and leaves and the bromatological composition. However, in relation to higher productivity, the amounts of nutrients absorbed by plants and accumulated in fruits were higher in treatments using mineral fertilization due to the higher yield. The bromatological analysis of fruits showed considerable contents of crude protein and ether extract, highlighting the potential of this species to human diet.

Highlights

Os frutos do maxixe do reino (Cyclanthera pedata) são utilizados tanto na culinária quanto para fins medicinais
This study aimed to assess the responses of caygua plants to green manure and mineral fertilizations, in relation to marketable fruit productivity, nutrient content in leaves and fruits and bromatological composition
Productivity of marketable caygua fruits was affected by the treatments (Figure 1), plant yield increased 156.52% with mineral fertilization when compared to the control treatment

Summary

Introduction

Os frutos do maxixe do reino (Cyclanthera pedata) são utilizados tanto na culinária quanto para fins medicinais. Esta pesquisa teve por objetivo estudar as respostas da cultura do maxixe do reino à adubação verde e mineral com nitrogênio na forma de ureia, quanto à produtividade de frutos comerciais, teor de nutrientes nas folhas e frutos e composição bromatológica. In Brazil, in the Northern Region of Minas Gerais State, caygua plants are especially grown by family farmers, where the fruits are traded in local markets (Fernandes et al, 2005; Costa et al, 2008) According to these authors, production areas are restricted to more fertile soils and their productivities are related, among other factors, to the crop nutritional management. Developing alternative nutritional management techniques related to nitrogen supply is necessary to produce this vegetable on small-scale farms (Fernandes et al, 2005)

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Results