Effect of Cropping System and Humidity Level on Nitrate Content and Tipburn Incidence in Endive

Alberto San Bautista,José Vicente Maroto,Bernardo Pascual,Andrea Gromaz,Rhuanito Soranz Ferrarezi,Salvador López-Galarza

doi:10.3390/agronomy10050749

Alberto San Bautista, José Vicente Maroto + Show 4 more

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https://doi.org/10.3390/agronomy10050749

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Abstract

Tipburn is an important disorder caused by a calcium deficiency that affects the marketability of endives. Genotype, air relative humidity, and temperature are directly involved in tipburn occurrence. Our study aimed to investigate the effect of cropping systems and relative humidity on the marketable yield, nitrate accumulation, and incidence of tipburn in endives. Two cultivars were evaluated in pots (‘Cuartana’ and ‘Natacha’), two cropping systems (greenhouse and open-field), and in two different air humidity levels (high level: plants under a plastic tunnel with an extra supply of humidity with micro-sprinklers, and low level: plants without an extra supply of humidity and outside of a plastic tunnel) during two years (2013 and 2014) in different growing seasons. Nitrate content was determined by reflectometry, and tipburn was evaluated using a qualitative scale. Results showed that tipburn was favored under greenhouse with low humidity levels, with 40–60% plants affected. ‘Natacha’ was more susceptible to tipburn (>20% plants affected) than ‘Cuartana’ (<20% plants affected). Leaf nitrate accumulation was favored by the highest temperatures (greenhouse). It is concluded that in our conditions, tipburn incidence in endives depends on the interaction of genotype and the environmental conditions. Nitrate content was more influenced by the temperature than by the cultivars used.

Highlights

In Spain, the annual consumption of fresh vegetables for prepared salads is about 6.67 kg person [1].The per capita consumption in the United Kingdom, France and Italy is 12, 6, and 4 kg, respectively; consumption in Belgium or Croatia is 4−10 times higher
The humidity level included low level and high level
Our experiment demonstrated that crop systems with low humidity levels favored the occurrence of tipburn in endives

Summary

Introduction

In Spain, the annual consumption of fresh vegetables for prepared salads is about 6.67 kg person [1]. The per capita consumption in the United Kingdom, France and Italy is 12, 6, and 4 kg, respectively; consumption in Belgium or Croatia is 4−10 times higher. Sales of fresh vegetables for prepared salads in Spain increased 57.8% in 2018 compared to the previous year, indicating its importance as a specialty crop [2]. Vegetables are the most important source of nitrate (NO3 − ) intake for humans, but the consumption of these compounds in high concentrations can be toxic. Leafy vegetables are especially prone to nitrate accumulation [3]. Nitrate is relatively non-toxic, it is converted to nitrites in the digestive system, which are associated with methaemoglobinemia, and the development of stomach cancer [4,5]

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