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

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.

Laranja de polpa vermelha: um estudo físico-químico e sensorial

“…O conteúdo de flavonoides totais e fenóis totais de ambas cultivares foram superiores ao encontrado por Kafkas et al (2009), estes autores analisaram variedades sanguíneas, encontrando variações de 121-239 mg.L -1 em flavonoides e de 441-527 mg.L -1 em fenóis totais. Kirinus et al (2018) estudaram as laranjas Navelinas e reportaram valores de 108,94 mg GAE.L -1 em conteúdo fenólico. O conteúdo e o perfil de compostos bioativos podem variar entre cultivares, pois, a atividade de enzimas e ativadores transcriptores de sua síntese sofrem influência da umidade relativa do ar (ITHAL; REDDY, 2004).…”

Application of chemical compounds during pre-harvesting to control post-harvesting green mold in citrus

“…This fungus spreads on several skin oil glands through pores and wounds (Ghooshkhaneh, Golzarian, & Mamarabadi, 2018). The reduction of r L might occur due to many factors, such as hydrogen peroxide production as a plant response, disturbances in catalase production secreted by fungus, maintenance of fruit pH reducing the efficiency of organic acid secretion by the pathogen (Costa et al, 2019), and phenolic compounds in citrus fruits (Kirinus et al, 2018). Reducing pre-and post-harvest losses is a constant challenge in the citrus production chain.…”