Postharvest quality of ‘Brookfield’ apple field-treated with naphthalene acetic acid alone or combined with other growth regulators

Abstract

The Gala cultivars represent about 65% of the Brazilian apple production, however, it has a short harvest period, making necessary to use technologies that anticipate or delay fruit maturation. A widely used technology is the preharvest application of growth regulators. The objective of this investigation was to evaluate the effect of preharvest application of naphthalene acetic acid (NAA) combined with aminoethoxyvinylglycine (AVG) and 2-chloroethylphosphonic acid (Ethephon), on the quality of 'Brookfield' apple at harvest and after eight months controlledatmosphere (CA) (1.2 kPa O 2 and 2.0 kPa CO 2) storage followed by seven days of shelf life at 20 °C. The treatments were: [1] Control: application of water only; [2] NAA (40 g.ha-1); [3] NAA (40 g•ha-1) plus Ethephon (2.0 L•ha-1 24% of active ingredient), and [4] NAA (40 g•ha-1) plus AVG (0.83 kg.ha-1 15% of active ingredient). At harvest, fruit treated with NAA presented a higher level of starch degradation, ethylene production and respiration rate. Fruit treated with NAA plus AVG maintained better quality after eight months under CA storage plus seven days of shelf life, due to higher healthy fruit amount and higher flesh firmness, but this combination reduced the red skin color index. Additionally, NAA plus Ethephon may be an alternative to maintain the quality of 'Brookfield' apple during storage in comparison to the application of NAA isolated.

Maturation of 'Baigent' apples protected by anti-hail nets and sprayed with aminoethoxyvinylglycine and ethephon

“…Likewise, Ozturk et al (2015) found a reduction in the ethylene production rate in 'Jonagold' apple sprayed with AVG in single and split rates of 225 mL -1 . AVG blocks the production of 1-aminocyclopropane-1-carboxylate (ACC), by inhibiting its synthase, reducing the production of ethylene in the fruit (Wendt et al, 2020). However, ethephon, when releasing ethylene, promotes the autocatalytic production of this phytohormone (Steffens et al, 2006).…”

“…Scolaro et al (2015) and Yildiz et al (2012) also observed a higher flesh firmness in 'Royal Gala' and 'Red Chief' apples, respectively, that received a pre-harvest application of AVG, when compared with the control. The higher flesh firmness found in fruits sprayed with AVG may be related to the lower rates of ethylene production and respiration, as well as to the lower activity of ACC oxidase (Wendt et al, 2020). However, this variation in results between years of production may also be related to the stage of fruit maturation at harvest, fruit position on the canopy, and the different environmental conditions during the crop cycle (Drogoudi & Pantelidis, 2011;Zheng et al, 2012).…”

Improving the productivity and marketability of Anna apples in response to specific growth regulator sprays under abiotic stresses

“…Anna apple fruit is a climacteric fruit, and a reduced in respiration is required to delay the climacteric peak in semi-arid regions (Abdel-Sattar and Kotb 2021). Previous studies have indicated that treating apple trees with 1-MCP or AVG before harvest with 30 days delays the climacteric peak of respiration and ethylene production during the ripening process, which extends the shelf life of climacteric fruits by delaying fruit ripening and senescence (Watkins 2006;Thongkum et al 2018;Lv et al 2020;Wendt et al 2020). Additionally, 1-MCP treatment that inhibits ethylene action may bene t fruit quality over an extended period after harvesting (Tomala et al 2020a).…”

“…MCP have been reported by previous studies to delay the synthesis of anthocyanins in the epidermis of Pink Lady(Whale et al 2008), Imperial Gala(Petri et al 2010), Royal Gala(Scolaro et al 2015), and Brook eld(Wendt et al 2020) apples because of the retarded development of red blush and reduced skin redness. In addition, when Brook eld apples were treated with NAA, the red color index was higher while it was lower with NAA + AVG treatment, and this delay the process of the skin color development to becomes red(Wendt et al 2020).…”

“…Preharvest treatments of apple trees with the speci c growth regulators such as 1-methylcyclopropene (1-MCP), naphthalene acetic acid (NAA) and aminoethoxyvinylglycine are widely used in various countries in all aspects of modern apple production to control excessive fruit drop, starch degradation, and fruit sizing by controlling cell division and expansion; they can also improve fruit quality and development while reducing ripening, which helps improve the postharvest life and nal quality of fruit for better marketability ( Exogenous application with 1-MCP (an inhibitor of ethylene action), AVG (an inhibitor of ethylene biosynthesis), and NAA (a synthetic auxin) can maintain fruit retention, yield, and quality while delaying fruit ripening and senescence; thus, treatment with these chemicals can help extend fruit marketability and achieve the highest possible return from an orchard in terms of fruit retention, optimal yield, superior fruit quality, and extending harvest (Greene and Wendt et al 2020). Such applications are used to reduce product losses between producers and consumers (Tomala et al 2020a) as well as to maintain sales and prices at affordable levels (Russia's and the EU's Sanctions 2020).…”