Cristiano André Steffens

Qualidade da maçã cv. Gala tratada com 1-metilciclopropeno

The objective of this work was to verify the efficacy of the initial application of 1-methylcyclopropene (1-MCP) and the effect of different reapplication dosis after 4 months of cold storage on quality of apple cv. Gala. The treatments originated from the combination between application time (at storage and after four months of storage) and dosis of 1-MCP (0, 312, 625nLL-1). The treatments were: 0+0nLL-1; 0+312nLL-1; 0+625nLL-1; 625+0nLL-1; 625+312nLL-1 and 625+625nLL-1. After 180 days of storage at 0.5oC and 14 days at 20oC, the initial application of 625nLL-1 of 1-MCP provided the highest flesh firmness, titratable acidity and maintained fruit skin greener. However, there was no effect on fruit decay and total soluble solid content. The reapplication of 1-MCP, after four months of storage, showed no effect on fruit quality. The application of 1-MCP after 14 days at 20°C at the beginning of the storage period, independently of the reapplication, maintained higher flesh firmness, higher levels of TSS and titratable acidity, greener skin color and lower decay incidence.

Effect of 1-MCP applied at different times during cold and Ca storage

ABSTRACT - The objective of this work was to evaluate the effect of 1-MCP applied at different period during the cold storage (CS) and in controlledatmosphere (CA) on the quality of ‘Quioto’. Persimmon. The experimental design was completely randomized with four replication s of 30 fruits andthe tested treatments were: cold storage (CS), cold storage + 1-MCP (1000ppb) in the beginning of the storage, cold storage + 1-MCP (1000ppb) in theend of the storage period; storage in controlled atmosphere (CA) with 1kPa of O 2 and 5kPa of CO 2 and 1kPa of O 2 and 5kPa of CO 2 + 1-MCP in the endof the storage, after 2 months of storage at –0.5°C, plus 5 days at 10°C and 3 days at 20°C. In the cooled storage, the 1-MCP, applied as in thebeginning of the storage as in the end of the storage, provided greater pulp firmness. For the parameters: total soluble solids, rottenness anddarkening of the peel didn’t have statistics difference between the treatments. There were no statistics differences between th e treatments for totalsoluble solids, rottenness and darkning of the peel. In conclusion 1-MCP applied in the beginning or end of storage period mant ained high firmmness.

Maçã 'Gala' armazenada em atmosfera controlada e tratada com aminoetoxivinilglicina e ethephon

Abstract – The objective of this work was to evaluate the effect of preharvest sprays of aminoethoxyvinylglycine(AVG) combined or not with ethephon on the quality of ‘Gala’ apples stored in controlled atmosphere. Thetreatments were: control, ethephon (140 g ha -1 ), AVG (125 g ha ), AVG (125 g ha -1 ) + ethephon (140 g ha -1 ), AVG(95 g ha -1 ) and AVG (95 g ha ) + ethephon (140 g ha -1 ). These treatments were combined with harvest date at 131,138 and 145 days after full bloom. The AVG and ethephon were applied 30 and 7 days before the first harvest,respectively. The application of AVG, combined or not with ethephon, afforded fruits with higher flesh firmness,greener peel color, reduced rot and physiological disorders incidence, lowered ethylene production and respiration.Fruits treated with ethephon showed a quality like control fruits. Application of ethephon in AVG treated plantsdid not affect the efficiency of AVG in the quality of apples after storage.Index terms: Malus domestica

Armazenamento de maçã 'gala' em atmosfera controlada com remoção de etileno

O objetivo deste trabalho foi avaliar o efeito de diferentes niveis de etileno na câmara sobre a manutencao da qualidade da maca cv. Gala, durante o armazenamento em AC. O delineamento experimental utilizado foi inteiramente casualizado com quatro repeticoes e a unidade experimental composta por 50 frutos. Os tratamentos utilizados foram: >10µl L-1 (sem absorcao); < 0,4µl L-1 e < 0,04µl L-1, cujos niveis mais baixos foram obtidos por absorcao quimica. Apos oito meses de armazenamento, na abertura das câmaras e apos sete dias a 20oC, verificou-se maior firmeza de polpa, maior acidez titulavel e menor ocorrencia de podridoes e degenerescencia senescente nos frutos armazenados com remocao do etileno. Quanto aos teores de solidos soluveis totais, nao houve diferenca estatistica entre os tratamentos, em ambas as avaliacoes. A coloracao da epiderme apresentou-se mais verde nos frutos armazenados sob remocao de etileno, apos sete dias de exposicao dos frutos a 20oC. A incidencia de polpa farinhenta foi menor nos tratamentos com eliminacao do etileno, na abertura das câmaras.

Maturação da maçã Fuji em função do atraso na colheita e da aplicação pré-colheita de aminoetoxivinilglicina

This research was carried out with the aim evaluating the effect of preharvest treatment with aminoethoxyvynilglycine and harvest delay on fruit drop and maturation of apple cultivar Fuji. The treatments were three doses of aminoethoxyvynilglycine (0,90 e 125g.ha-1) combined with three harvest dates (195, 204, 225 days after full bloom). No interaction between doses of aminoethoxyvynilglycine and harvest date was found. The application of aminoethoxyvynilglycine in the apple cultivar Fuji maintained greener ground skin color, reduced ethylene production, respiration rate and watercore incidence. Delaying fruit harvest showed lower respiration, better red color and higher total solids soluble. In addition to this, late harvest caused higher fruit drop, skin yellowing, high watercore incidence, high starch index, high ethylene production, low flesh firmness and low titratable acidity.

METHODS OF FRUIT TISSUE SAMPLING TO QUANTIFY CALCIUM AND MAGNESIUM CONTENTS TO SEGREGATE APPLES FOR BITTER PIT INCIDENCE

Susceptibility to bitter pit (BP) has been associated with low Ca content and high Mg/Ca ratio in the fruit, which is highly affected by fruit genotype. This study was carried out to identify the best fruit tissue sampling method to assess Ca and Mg contents to segregate apples for BP occurrence. ‘Fuji’ and ‘Catarina’ apples (with low and high susceptibilities to BP, respectively) were segregated in lots without and with BP symptoms, after four months of cold storage (0±0.5°C/95% RH), and then analyzed for Ca and Mg contents by three fruit tissue sampling methods: peel+flesh, peel, and flesh. For peel+flesh, a wedge-shaped segment was cut longitudinally from the fruit, discarding the core tissue. The fruit calyx-end was used for peel (thickness of 2 mm) and flesh (thickness of 2-8 mm) sampling. For peel+flesh and flesh, Ca content was lower and Mg/Ca ratio was higher in fruit with BP in both cultivars. For peel, only in ‘Fuji’, Ca content was lower and Mg/Ca ratio was higher in fruit with BP. In ‘Catarina’, Mg/Ca ratio in the flesh tissue at the calyx-end increased from 1.83 in fruit without BP to 4.56 in fruit with BP (~2.5-fold increase), while in ‘Fuji’ this ratio increased from 0.96 in fruit without BP to 1.29 in fruit with BP (~1.3-fold increase). Therefore, the high susceptibility to BP in ‘Catarina’ might be explained by its high Mg/Ca ratio in the flesh tissue under the peel, at the calyx-end of the fruit, were the symptoms appeared. Nonetheless, the results show that the Mg/Ca ratio in the flesh at the calyx-end is more suitable to segregate apple fruit for BP susceptibility in both cultivars. INTRODUCTION The incidence of bitter pit (BP) in apples is commonly associated with low calcium (Ca) concentrations in the fruit (Ferguson and Watkins, 1989; Saure, 2005). However, fruit Ca concentration alone may not be informative in relation to BP development. It is believed that a high magnesium (Mg) content exacerbates the potential for apple fruit to initiate the chain of reactions leading to BP symptoms development (Burmeister and Dilley, 1994; Amarante et al., 2013). Due to the ionic similarity between Ca and Mg, these two minerals strongly compete in various cellular processes, such as enzyme activation and membrane stabilization processes (White and Broadley, 2003). Although Mg can replace Ca at the binding sites, Mg cannot replace the role of Ca in the cellular processes, and the competition between these ions may explain the occurrence of physiological disorders related to Ca deficiency in response to high Mg/Ca ratios in fruit tissues (de Freitas et al., 2010). Thus, the quantification of Ca and Mg contents represents an important approach to predict BP development in apple fruit (Amarante et al., 2006, 2013). Calcium and Mg concentrations vary according to the fruit tissue analyzed (Amarante et al., 2006; Miqueloto et al., 2011). Although a few approaches have been developed to predict BP development in apple fruit based on Ca and Mg contents, there are limited studies focused on determining the most appropriate tissue to be sampled for that purpose. The sampling method most used today is the removal of a longitudinal slice, Proc. V International Conference Postharvest Unlimited Eds.: G.A. Manganaris et al. Acta Hort. 1079, ISHS 2015 360 containing peel+flesh tissues (Perring and Wilkinson, 1965; Argenta and Suzuki, 1994), involving different parts of the fruit (proximal, medial and distal), which reduces the ability to predict the occurrence of BP in apples (Amarante et al., 2006, 2013). As BP symptoms mainly occur at the fruit distal end tissue, peel and flesh sampling at that region are possibly the most appropriated methods to quantify Ca and Mg contents related to BP development (Amarante et al., 2013; Miqueloto et al., 2011). This study was carried out to identify the best fruit tissue sampling method to assess Ca and Mg contents in apple cultivars with low (‘Fuji’) and high (‘Catarina’) susceptibility to BP, aiming to segregate apples for BP incidence. MATERIALS AND METHODS ‘Fuji’ and ‘Catarina’ apples were harvested at commercial maturity from a commercial orchard in São Joaquim, State of Santa Catarina, Southern Brazil, in 2012. The orchard was not sprayed with Ca formulations during the growing season to favor BP development. Fruit were left in cold storage (0±0.5°C and 95% RH) for four months. After five days at room temperature (20±4°C and 70-80% RH), fruit of both cultivars were segregated in lots without and with BP. Fruit were gently washed with distilled water, left to dry and then analyzed for Ca and Mg contents in peel+flesh, peel and flesh. A longitudinal wedge-shaped segment (1 cm wide at the equator region), without core tissue, was used for peel+flesh sampling method (Fig. 1A), while the calyx-end was used for peel (thickness of 2 mm) and flesh (thickness of 2-8 mm) sampling methods (Fig. 1B). In the same fruits, samples were removed by the three different methods. In both cultivars, the experiment followed a completely randomized design, with 10 replications, each replication composed of 10 fruit. The fruit samples were digested with a mixture of sulfuric acid and hydrogen peroxide for quantification of Ca and Mg contents (mg kg fresh weight). The digested samples were then analyzed with an inductive coupled plasma spectrophotometer (ICP). Mineral attributes (Ca and Mg contents, and Mg/Ca ratio) quantified in the peel+flesh, peel and flesh were submitted to analysis of variance (p<0.05) to compare fruit without and with BP, for each cultivar, using SAS software (SAS Institute Inc., 2002). RESULTS AND DISCUSSION In ‘Fuji’, only Mg content in the flesh was not statistically different between fruit without and with BP (Table 1). In ‘Catarina’, Mg content in the peel+flesh and peel, and Ca content and Mg/Ca ratio in the peel were not different between fruit without and with BP (Table 1). For peel+flesh and flesh tissues, Ca content was lower and Mg/Ca ratio was higher in fruit with BP, in both cultivars (Table 1). However, in ‘Fuji’ peel tissue Ca content was lower and Mg/Ca ratio was higher in fruit with BP. Calcium and Mg contents at the calyx-end of the fruit were higher in the peel than in the flesh in both cultivars, regardless of BP incidence (Table 1). The results are in agreement with other studies, showing that total Ca and Mg contents are higher in the peel than in the flesh tissue of apples (Lewis and Martin, 1973; Ferguson and Watkins, 1983; Amarante et al., 2006, 2013; Miqueloto et al., 2011). In ‘Fuji’, the total Ca and Mg contents in the flesh corresponded respectively to ~26 and ~43% of those observed in the peel, regardless of BP incidence. In ‘Catarina’, the total Ca and Mg contents in the flesh corresponded respectively to ~13 and ~41% of those observed in the peel, regardless of BP incidence. Therefore, ‘Catarina’ (more susceptible to BP) has a more pronounced reduction of Ca content in the flesh compared to the peel tissue than ‘Fuji’ (less susceptible to BP) at the calyx-end, while for Mg the reduction in content from peel to flesh is similar in the two cultivars. As the decrease of Mg content from peel to the flesh was lower compared to Ca content, the Mg/Ca ratio value was higher in the flesh than in the peel in both cultivars, regardless of BP incidence (Table 1). The Mg/Ca ratio increase from peel to flesh was