AVG application regimes play an important role on pre-harvest drop and ripening of ‘Jonagold’ apples

Abstract

This study was carried out to investigate the effects of different AVG (aminoethoxyvinylglycine) treatments on pre-harvest fruit drop rates and ripening levels of 'Jonagold' apples. A total of 225 mg L -1 AVG dose was applied at once in a single application at different times or divided into doses and applied different times. Compared to control treatment, entire AVG treatments increased fruit removal force and significantly decreased the pre-harvest drop rates. AVG treatments applied at once (225 mg L -1 ) 8 or 4 weeks before the anticipated harvest time were found to be more effective than the divided treatments. AVG treatments inhibited ethylene biosynthesis and such an inhibition was more distinctive in single 225 mg L -1 treatments. AVG treatments decreased flesh softening, starch degradation rates and consequently retarded fruit ripening. The 225 mg L -1 AVG treatment applied 4 weeks before the harvest significantly increased L* value and hue angle both in the year 2010 and 2011. NAA (naphtaleneacetic acid) at 10 mg L -1 sprayed 4 and 2 weeks before anticipated harvest was found to be insignificant in control of pre-harvest fruit drops. NAA treatment decreased flesh firmness, and did not have any significant effects on ethylene biosynthesis. Key words: Colour, ethylene, firmness, fruit removal force, starch degradation ResumoO presente estudo foi realizado para investigar os efeitos de diferentes tratamentos AVG (aminoetoxivinilglicina) sobre as taxas de queda de frutos antes da colheita e níveis de amadurecimento de maçãs 'Jonagold'. Foi aplicada uma dose AVG total de 225 mg L -1 numa só vez numa única aplicação em momentos diferentes ou dividida em doses aplicadas e tempos diferentes. Em comparação ao tratamento controle, as aplicações de AVG aumentaram a força de remoção dos frutos e reduziram significativamente as taxas de queda na pré-colheita. A aplicação de AVG de uma só vez (225 mg L -1 ) ou 4 a 8 semanas antes da época da colheita mostrou-se mais eficaz do que as aplicações efetuadas em doses. O tratamento com AVG inibe a biossíntese de etileno, sendo que esta inibição se verificou mais significativa em tratamentos individuais de 225 mg L -1 . O tratamento com AVG diminuiu o amolecimento da polpa, as taxas de degradação do amido e consequentemente retardou o amadurecimento dos frutos. O tratamento com doses de 225 mg L -1 de AVG aplicadas quatro semanas antes da colheita aumentou significativamente o valor L * e o ângulo de cor, tanto no ano de 2010 como de 2011. A pulverização de NAA (ácido naftaleno acético) a 10 mg L -1 2 a 4 semanas antes da colheita foi considerada insignificante no controle da queda de frutos na pré-colheita. O tratamento com NAA diminuiu a firmeza da polpa, e não tem quaisquer efeitos significativos sobre a síntese de etileno. Palavras-chave: Cor, etileno, firmeza, força de remoção dos frutos, degradação do amido 1 Assist. Prof. Dr.,

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

“…In the 2015/2016 season, there was an interaction between the factors pre-harvest treatments and harvest date; however, regardless of the harvest date, any form of pre-harvest application of AVG caused a lower rate of ethylene production than the control. 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).…”

“…These results are in agreement with those of Ozkan et al (2012), who found a delay in the development of the red color in the epidermis of 'Braeburn' apples sprayed with a single rate of AVG. Ozturk et al (2015) reported that the application of AVG in a single rate resulted in a less intense red color in the epidermis of 'Jonagold' apple than split rates.…”

Aminoethoxyvinylglycine (AVG) Uygulamasının Red Chief ve Braeburn Elma Çeşitlerinde Hasatönü Meyve Dökümü ve Meyve Kalitesi Üzerine Etkisi

“…The physiological events regulated by ethylene, such as ethylene synthesis and therefore pre-harvest fruit drop, may be prevented by aminoethoxyvinylglycine (AVG) binding to the active site of enzyme 1-aminocyclopropane-1carboxylate synthase (ACS) and inhibiting theisis of ethylene immediate precursor aminocyclopropane-1carboxylate (ACC), which is thereafter converted into ethylene by ACC oxidase (ACO) (Huai et al, 2001). AVG, which inhibits the increase in internal ethylene, has been shown to be effective in preventing pre-harvest fruit drop (Byers, 1997;Kang et al, 2007;Dal Cin et al, 2008;Robinson et al, 2010;Yildiz et al, 2012;Ozturk et al, 2015;Aglar et al, 2016;Souza et al, 2019). In the study, smilarly with these results, AVG application had a positive effect on preserving the fruit retention force and thus preventing fruit drop, but this effect varied depending on the cultivar and application concentration.…”

“…Since the abscission and maturation events occur simultaneously, the biochemical role of ethylene in abscission is unclear, it is known that the process following the initiation of abscission is accelerated by ethylene (Arseneault et al, 2016). Due to the effect of the auxin-ethylene interaction on the fruit drop, the effects of the bioregulators such as naphthalene acetic acid (NAA) that promotes auxin concentration (Yuan and Carbaugh, 2007;Dal Cin et al, 2008) and AVG that inhibits ethylene increase (Byers, 1997;Kang et al, 2007;Dal Cin et al, 2008;Yildiz et al, 2012;Ozturk et al, 2015;Aglar et al, 2016;Souza et al, 2019) on the pre-harvest fruit drop have been determined by previous studies. It has been reported that AVG is more effective than NAA in preventing pre-harvest fruit drop in apples (Greene et al, 1987, Yildiz et al, 2012.…”

Ethylene-regulated immature fruit abscission is associated with higher expression of CoACO genes in Camellia oleifera

“…It has been shown that ethylene is the main signal molecule to induce fruit abscission in apple, oil palm and litchi [13][14][15]. Moreover, studies have shown that the fruit-setting rates can be improved by applying ethylene inhibitor AVG in apple [16]. In general, ethylene biosynthesis may be involved in the abscission process, and it plays an important role in the final stage of abscission.…”