Resumen En muchos tejidos vegetales, se ha utilizado el acondicionamiento a baja temperatura (LTC) para inducir respuestas adaptativas poscosecha para superar las consecuencias del daño por frío (CI). Este estudio tuvo como objetivo investigar si el LTC es eficaz para reducir la incidencia de daño por frío (CI) en cultivares de batata. Las raíces de batata BRS Cuia y BRS Rubissol se sometieron a almacenamiento en frío (6 °C o 13 °C) y LTC (10 °C durante 7 días, seguido de un segundo almacenamiento a 6 °C). El LTC aumentó la tolerancia de las raíces de la batata al IC mediante la activación del sistema antioxidante, principalmente en el cv. BRS Rubissol, que se asoció notablemente con un mayor contenido de fenoles solubles totales y prolina, así como una mayor actividad de la fenilalanina amonio liasa. Además, no se observaron lesiones externas ni internas en las raíces de LTC, manteniendo la calidad para el procesamiento, lo que indica que el LTC es eficaz para mitigar el daño por frío en los cultivares brasileños de batata.

Abstract In many plant tissues, low-temperature conditioning (LTC) has been used to induce postharvest adaptive responses to overcome chilling injury (CI) consequences. This study aimed to investigate whether LTC is effective in reducing the incidence of chilling injury (CI) in sweet potato cultivars. Sweet potato roots BRS Cuia and BRS Rubissol were submitted to cold storage (6 °C or 13 °C) and LTC (10 °C for 7 d, followed by second storage at 6 °C). LTC increased the tolerance of sweet potato roots to CI via antioxidant system activation, mainly in cv. BRS Rubissol, which was markedly associated with higher content of both total soluble phenolics and proline, as well as increased activity of phenylalanine ammonium lyase. Moreover, no either external or internal injuries were observed in the LTC roots, maintaining the quality for processing, which indicates that the LTC is effective in mitigating chilling injury in Brazilian sweet potato cultivars.

ABSTRACT High incidence of sprouts and loss of quality of sweet potato is one of the negative aspects that compromises the commercialization most, and the methods of sprout control are still very limited. The appearance of sprouts promotes the wilting of sweet potato roots, reducing their commercialization period. The main objectives of this study were to evaluate sprout control and physiological and biochemical changes, in addition to the impact on the quality of postharvest chips in sweet potato roots cultivar BRS Cuia treated with methyl jasmonate (MeJa) and nonanoic acid (NA). Roots were fogged with 10 μmol·L–1 MeJa or 5 μmol·L–1 NA applied at first sprout initiation and control. Physiological and biochemical alterations such as fresh weight loss assessment, sprouting incidence and sprout length, total soluble sugars, reducing sugars, nonreducing sugars, enzymatic peroxidase and polyphenol oxidase, chips quality after frying were then assessed. Besides that, to determine the influence of treatments and storage periods, multivariate analysis was also performed using the main components. The MeJa reduced the incidence of sprouting and maintained the root quality during storage at room temperature. Notably, such events led to an increased both shelf life and potential of commercialization. Moreover, MeJa-treated chips displayed lighter color appearance after frying than control and NA-treated roots. Roots fogged with NA did not suppress the growth of sprouts, which consequently triggered a higher browning intensity in fried sweet potato chips.

Resumo: O objetivo deste trabalho foi avaliar a ação do paclobutrazol (PBZ) sobre o crescimento e valor ornamental de dois acessos e duas cultivares comerciais de pimenta ornamental - Biquinho Vermelha e Bode Amarela. Uma solução aquosa de 250 mL de PBZ foi adicionada aos vasos com 0, 20, 40 e 60 mg L-1 i.a., quando as plantas apresentavam 12 cm de altura. Ao final do crescimento, determinaram-se os seguintes parâmetros: a altura das plantas, o teor de clorofila das folhas, o número de frutos e de folhas, e a compacidade da parte aérea no estádio de maturidade das plantas, com 30% de frutos maduros. Independentemente da concentração de PBZ aplicada, houve redução da altura das plantas e aumento da concentração de clorofila nas folhas. O PBZ não melhorou as características ornamentais dos genótipos 'Biquinho Vermelha' e 2334PB, o que resultou em plantas inadequadas aos requisitos do mercado. Para os genótipos 2345PB e 'Bode Amarela', a aplicação de 20 mg L-1 de PBZ é a mais indicada e resulta em plantas com características ornamentais adequadas requeridas pelo mercado nacional de flores e plantas ornamentais.

Abstract: The objective of this work was to evaluate the action of paclobutrazol (PBZ) on the growth and ornamental value of two pepper accessions and two commercial cultivars of ornamental pepper - Biquinho Vermelha and Bode Amarela. A PBZ aqueous solution (250 mL) was used to soak the substrate at 0, 20, 40, and 60 mg L-1 a.i. concentrations when the plants had 12 cm height. At the end of plant growth, the follwoing parameters were evaluated: plant height, chlorophyll content in leaves, number of fruit and leaves, and canopy compactness at the time the plants reached maturity to be marketed, with 30% of ripe fruit. Irrespective of the applied PBZ concentration, plant height diminished, and chlorophyll content increased. PBZ did not improve the ornamental characteristics of the genotypes 'Biquinho Vermelha' and 2334PB, which resulted in unsuitable plants for market requirements. For the genotypes 2345PB and 'Bode Amarela', the application of 20 mg L-1 of PBZ is the most indicated, and it results in plants with adequate ornamental characteristics required by the national market of flowers and ornamental plants.