&lt;b&gt;‘Navelina’ oranges submitted to pre-harvest resistance inducers

Marines Batalha Moreno Kirinus,Pricila Santos Da Silva,Marcelo Barbosa Malgarim,Caroline Farias Barreto,Roberto Pedroso De Oliveira,José Carlos Fachinello

doi:10.4025/actasciagron.v40i1.39465

<b>‘Navelina’ oranges submitted to pre-harvest resistance inducers

Marines Batalha Moreno Kirinus, Pricila Santos Da Silva + Show 4 more

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https://doi.org/10.4025/actasciagron.v40i1.39465

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Abstract

The objective of this study was to evaluate the physical-chemical characteristics, rot index and bioactive compounds of ‘Navelina’ oranges under postharvest refrigerated storage conditions after pre-harvest resistance induction in crops from 2015 and 2016. The field experimental design was completely randomized blocks. The treatment factors were composed of the following resistance inducers: noresistance inducer (control), selenium (Se), silicon (Si), acibenzolar-s-methyl (ASM), methyl jasmonate (MeJa), thiamethoxam (TMT) and imidacloprid (IMI). In the laboratory, the experimental design was the same as that in the field, but it used a two-factor scheme instead of a unifactorial scheme. In the two-factor scheme, factor A was composed of the abovementioned resistance inducers, and factor B was composed of the refrigerated storage periods (zero and 30 days). The analyses investigated the coloration, fresh mass loss, rot index, soluble solids, pH, titratable acidity, SS/TA ratio, ascorbic acid, total phenolic compounds and antioxidant capacity of the oranges. The application of pre-harvest resistance inducers was efficient in maintaining the physical-chemical characteristics of the ‘Navelina’ oranges in postharvest, increasing their bioactive compounds in comparison to the control. The resistance inducers Se, Si, MeJa, and IMI reduced rot rates, while ASM and MeJa prevented fresh fruit mass loss.

Highlights

The orange production area of Brazil is the largest in the world; compared to other countries, it has the 10th highest productivity
This study aimed to evaluate the physical-chemical characteristics, rot indexes and bioactive compounds of ‘Navelina’ oranges under postharvest refrigerated storage after resistance induction in the pre-harvest 2015 and 2016 crops
An investigation on the effectiveness of the methyl jasmonate (MeJa) resistance inducer applied during pre-harvest in mangoes (Mangifera indica L.) showed uniform development of the red color in the peel after harvesting, with an increase in the L* and a* values (Muengkaew, Chaiprasart, & Warrington, 2016)

Summary

Introduction

The orange production area of Brazil is the largest in the world; compared to other countries, it has the 10th highest productivity. The orange sector is highly organized and competitive, accounting for 30% of the global production and comprising one of the largest centers of orange juice production; in addition, over 19 million tons of oranges are harvested per productive cycle (FAO, 2016). Orange trees are susceptible to various diseases, primarily citrus canker. These diseases cause economic damage to production, increasing costs. The most frequent procedure for disease control consists of the use of agrochemicals and resistant cultivars and the encouragement of positive cultural practices and crop management. The induction of systemic acquired resistance (SAR) is a promising alternative for disease control, as it exploits a natural defense mechanism of plants. Sensitive plants can acquire a greater ability to defend against

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