Cassandro Vidal Talamini do Amarante

Relationship between character of skin cover of coated pears and permeance to water vapour and gases

Abstract Pear fruit (Pyrus communis L.) with different skin characteristics (non-lignified: ‘Bartlett’, ‘Doyenne du Comice’ and ‘Packhams Triumph’; or with lignified cells in the skin: ‘Beurre Bosc’) were treated at harvest with a carnauba-based wax emulsion at concentrations of 0, 5, 10, 20, 40, and 100% (v/v) of the commercial formulation to achieve different coating deposits on the skin and assessed for skin permeance at 20°C and 60–70% RH. ‘Bartlett’ had the highest natural skin permeance to water vapour and gases, followed by ‘Bosc’, ‘Comice’ and ‘Packhams’. Small increases in coating deposit on the skin substantially reduced permeance to H2O (P′H2O), O2 (P′O2) and CO2 (P′CO2) in cultivars with non-lignified skin, by improving coverage of cracks in the cuticle and blockage of lenticels. These cultivars also underwent a larger reduction in P′O2 than P′CO2 with increasing coating deposits. While ‘Bartlett’ and ‘Comice’ showed a more variable reduction in P′O2 than in P′CO2 with increases in coating deposit, the inverse was observed for ‘Packhams’. ‘Bosc’, with lignified cells in the skin, had only small changes in P′H2O with waxing. In addition, P′O2 and P′CO2 decreased similarly and more gradually with increasing coating deposits in ‘Bosc’ than in the other cultivars. The epidermis of ‘Bosc’, comprising an irregular layer of lignified cells, seemed to have high P′H2O and low P′O2 and P′CO2. Improving the coating deposit on the skin blocked the lenticels, providing a more variable reduction in P′CO2 than in P′O2. However, this did not effectively cover the lignified cells in the epidermis, providing variable and small changes in P′H2O. These results show that optimisation of surface coatings for pears must take into account differences in the nature of the skin.

Effects of coating concentration, ripening stage, water status and fruit temperature on pear susceptibility to friction discolouration

Abstract Pear fruit ( Pyrus communis L.) cv. ‘Duyenne du Comice’ were treated at harvest with different concentrations of a carnauba-based wax emulsion and assessed for susceptibility to friction discolouration (FD) after different periods in cold storage. Susceptibility to FD was low at harvest but increased with storage, especially between 1 and 2 months storage. Concomitantly, higher coating concentrations were required to reduced FD with prolonged storage; coating concentrations of 20 and 40% were necessary to reduce FD for fruit damaged after 1 and 2 months storage, respectively. Increasing coating concentration reduced internal O 2 partial pressure and reduced water loss. The lower internal O 2 level in coated fruit was associated with delayed ripening and reduced fruit susceptibility to FD. Reduced water loss preserved the integrity of skin and reduced susceptibility to FD. Higher levels of FD were observed at temperatures lower or higher than 10–20°C. The physical protection provided by skin coatings in combination with their effects on fruit physiology, presents a useful opportunity to reduce FD after cold storage, if adopted in conjunction with adequate temperature and humidity control during storage and post-storage handling of the fruit.

Ripening and quality of 'Laetitia' plums following harvest and cold storage as affected by inhibition of ethylene action

Abstract – The inhibition of ethylene action by 1-methylcyclopropene (1-MCP) extends shelf and storagelife of many climacteric fruits. However, 1-MCP appears to have limited effects on stone fruit dependingon specie and cultivar. The effects of 1-MCP on ripening and quality of ‘Laetitia’ plums were determinedduring ripening at 23 o C following harvest and cold storage. Japanese plums ( Prunus salicina , cv. Laetitia)were harvested at mature pre-climacteric stage, cooled to 2 o C within 36 hours of harvest and then treatedwith 0, 0.05, 0.10, 0.50 or 1.00 µL L -1 of 1-MCP at 1°C for 24 hours. Following treatment, fruits wereeither held at 23 o C for 16 days or stored at 1 o C for 50 days. Fruits were removed from cold storage at 10-day intervals and allowed to ripe at 23°C for five days. A delay of climacteric respiration and ethyleneproduction by 1-MCP treatment during ripening following harvest and cold storage was associated to aslow rate of fruit softening. 1-MCP treatment also delayed the loss of titratable acidity and changes of fleshand skin color, whereas it had little or no effect on soluble solids content. 1-MCP effects were concentration-and storage duration-dependent and, generally, a saturation fruit response to 1-MCP occurred between 0.5and 1.0 µL L

Análise multivariada da fauna edáfica em diferentes sistemas de preparo e cultivo do solo

The objective of this work was to evaluate the effect of different soil tillage and crop management systems on soil fauna groups, by means of multivariate analysis. In the canonical discriminant analysis the conservation soil management systems with crop succession were discriminated in relation to other treatments with crop rotation. The groups Acarina, Hymenoptera, Isopoda, and Collembola, and the Shannon index (H) showed the highest contribution for the discrimination between treatments. The correspondence analysis showed a strong association between Acarina and Hymenoptera groups with the treatment no-tillage with crop succession, and between Collembola group with the conventional tillage system.The objective of this work was to evaluate the effect of different soil tillage and crop management systems on soil fauna groups, by means of multivariate analysis. In the canonical discriminant analysis the conservation soil management systems with crop succession were discriminated in relation to other treatments with crop rotation. The groups Acarina, Hymenoptera, Isopoda, and Collembola, and the Shannon index (H) showed the highest contribution for the discrimination between treatments. The correspondence analysis showed a strong association between Acarina and Hymenoptera groups with the treatment no-tillage with crop succession, and between Collembola group with the conventional tillage system.

Análise multivariada de atributos do solo em sistemas convencional e orgânico de produção de maçãs

Este estudo foi conduzido em pomares de macas nos sistemas de manejo convencional e orgânico, com o objetivo de identificar diferencas entre os dois sistemas de producao, com base em atributos microbiologicos e quimicos do solo, por meio de metodos multivariados, como a analise canonica discriminante (ACD) e a analise de correlacao canonica (ACC). Em ambos os pomares, foram feitas amostragens em 24 plantas distribuidas em uma grade de 45x54 m, em duas epocas, para a quantificacao de teores de carbono da biomassa microbiana (CBM), carbono orgânico total do solo (COT), nitrogenio da biomassa microbiana (NBM), nitrogenio total do solo (NT), relacao CBM:COT, relacao NBM:NT, respiracao basal (C-CO2) e quociente metabolico (qCO2), alem da determinacao de atributos quimicos destes solos. A ACD identificou o CBM como o atributo microbiologico mais importante pela analise multivariada, na separacao entre os pomares, seguido do qCO2 e da relacao NBM:NT. Atributos microbiologicos e quimicos relacionados ao carbono foram mais sensiveis as variacoes entre os sistemas do que os relacionados ao nitrogenio. Houve alta correlacao canonica entre os atributos microbiologicos e quimicos do solo nos pomares, com destaque para o CBM, entre os atributos biologicos, e para o pH H2O e aluminio, entre os atributos quimicos.

Characterising ripening behaviour of coated pears in relation to fruit internal atmosphere

Abstract Pear ( Pyrus communis L.) cultivars ‘Bartlett’, ‘Beurre Bosc’, ‘Doyenne du Comice’, and ‘Packhams Triumph’ were treated at harvest or after cold storage with concentrations of 0, 5, 10, 20, 40, and 100% (v/v) of a commercial carnauba-based wax emulsion. Fruit were assessed for ripening and internal atmosphere composition at 0°C/90–95% RH (only for ‘Comice’) and at 20°C/60–70% RH (for all cultivars, after they achieved the chilling requirement to ripen). For all cultivars coated at harvest and ripening at 20°C, respiration rates, softening and colour change followed a Michaelis–Menten model when plotted against internal partial pressure of O 2 p O 2 i , while internal partial pressure of CO 2 ( p CO 2 i ) had virtually no explanatory power for these variables. This supports the notion that modification of p O 2 i rather than p CO 2 i is the principal means by which coating achieves its effects on ripening behaviour of pears during shelf life. Michaelis–Menten constant values ( K m ) for respiration and softening were lower than those for colour change for all cultivars at 20°C. This resulted in colour change being retarded by any level of depression in p O 2 i created by coating, while firmness was substantially reduced only at much lower p O 2 i during shelf life. Plots of p CO 2 i and respiration versus p O 2 i for fruit coated either pre-climacteric (at harvest) or entering the climacteric (after cold storage), indicated that ‘Comice’ and ‘Packhams’ were tolerant to hypoxia whereas, with ‘Bartlett’ and ‘Bosc’, tolerance reduced with advancing ripening, and the latter cultivar was the least tolerant of all four cultivars. During storage at 0°C of ‘Comice’, coatings had a more substantial effect in delaying softening than colour change; firmness retention seemed to be related to increase of p CO 2 i , while the limited suppression of colour change seemed to be related to small reductions of p O 2 i . Therefore, optimisation of surface coatings for pears must account for differences between cultivars and ripening stage at which fruit are coated, as well as the temperature at which the fruit are going to be held.

Atributos microbianos e químicos do solo em sistemas de produção convencional e orgânico de maçãs no estado de Santa Catarina

The study was carried out in Urupema, state of Santa Catarina, to evaluate the effects of conventional and organic apple production systems on soil microbial biomass, soil microbial activity and the relationship between soil microbial biomass attributes and C and N soil contents. The soil under the canopy of 24 plants (0-10 cm) was sampled in a 45 x 54 m grid, in both orchards (conventional and organic), in December 2002 and June 2003, and analyzed for: microbial biomass carbon (MBC), total organic carbon (TOC), microbial biomass nitrogen (MBN), total nitrogen (TN), basal respiration (C-CO2), MBC:TOC and MBN:TN ratios, and metabolic quotient (qCO2). The values of MBC, TOC, and MBC:TOC ratio were higher in the organic than in the conventional orchard on both sampling dates. The attributes of MBN, TN, and MBN:TN ratio were the least sensitive to management systems and sampling dates. Unlike sampling dates, C-CO2 did not differ significantly in the treatments. Highest qCO2 values were found in the conventional orchard.

Qualidade de goiaba-serrana em resposta à temperatura de armazenamento e ao tratamento com 1-metilciclopropeno

The objectives of this work were to characterize the postharvest physiology and to evaluate the effects of temperature and treatment with 1-methylcyclopropene (1-MCP) on the postharvest quality of fruits of feijoa (Acca selowiana) accessions from the germplasm bank of Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina. Fruits were harvested at commercial maturity. The genotypes Brasil (accession no. 387) and Uruguai (accession no. 454) were evaluated for respiration and ethylene production at 20oC, and respiration rates and skin color alterations at 0, 5, 10, 20, 30oC. The genotype Brasil (accession no. 242) was evaluated for ripening at 4oC, after treatment with 1-MCP (0, 500 and 1,500 ppb). Brasil (accession no. 387) and Uruguai (accession no. 454) exhibited a climacteric pattern, with a peak of ethylene evolution and respiration rate at the 8 and 12 days of storage at 20C, respectively. There was no signifi cant difference for respiration rates and ethylene evolution between these genotypes at this temperature. There was a substantial increase of respiration rate in both genotypes with the increase in temperature from 0 to 30oC, with a metabolic coeffi cient of approximately 3.5. With the increase in temperature, fruits of the genotype Brasil showed the greatest change of skin green color, while fruits of the genotype Uruguai exhibited the greatest darkening of skin. Feijoa fruits of genotype Brasil (accession no. 242) had delayed ripening when treated with 1-MCP and stored at 4C.The objectives of this work were to characterize the postharvest physiology and to evaluate the effects of temperature and treatment with 1-methylcyclopropene (1-MCP) on the postharvest quality of fruits of feijoa (Acca selowiana) accessions from the germplasm bank of Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina. Fruits were harvested at commercial maturity. The genotypes Brasil (accession no. 387) and Uruguai (accession no. 454) were evaluated for respiration and ethylene production at 20oC, and respiration rates and skin color alterations at 0, 5, 10, 20, 30oC. The genotype Brasil (accession no. 242) was evaluated for ripening at 4oC, after treatment with 1-MCP (0, 500 and 1,500 ppb). Brasil (accession no. 387) and Uruguai (accession no. 454) exhibited a climacteric pattern, with a peak of ethylene evolution and respiration rate at the 8th and 12th days of storage at 20oC, respectively. There was no significant difference for respiration rates and ethylene evolution between these genotypes at this temperature. There was a substantial increase of respiration rate in both genotypes with the increase in temperature from 0 to 30oC, with a metabolic coefficient of approximately 3.5. With the increase in temperature, fruits of the genotype Brasil showed the greatest change of skin green color, while fruits of the genotype Uruguai exhibited the greatest darkening of skin. Feijoa fruits of genotype Brasil (accession no. 242) had delayed ripening when treated with 1-MCP and stored at 4oC.

Thidiazuron effects on shoot growth, return bloom, fruit set and nutrition of apples

Abstract – Apple ( Malus domestica Borkh.) trees, cultivars Gala and Fuji, were sprayed at full bloomwith thidiazuron (TDZ) at doses of 0, 5, 10, or 20 g ha -1 of a.i. in order to evaluate its effects on plantgrowth and development, return bloom, fruit set, nutrition, and fruit yield. Fruit set increased withTDZ dose in ‘Gala’ but not in ‘Fuji’. TDZ did not affect fruit yield in any cultivar. In ‘Gala’, the returnbloom was reduced in about 50% at TDZ doses of 10 or 20 g ha -1 . TDZ increased shoot growth in bothcultivars. In leaves, TDZ decreased the concentration of Ca and Mg in ‘Gala’ and of Mg in ‘Fuji’, butdid not affect the chlorophyll content, leaf area, length, width, and dry mass per cm 2 regardless ofcultivar. In fruits, the effect of TDZ varied according to the portion evaluated. Highest doses of TDZdecreased the concentration of Ca and K in ‘Gala’ and of K in ‘Fuji’ in the entire fruits (flesh + skin); inthe skin, highest doses of TDZ reduced the levels of N, Ca, and Mg in both cultivars, in addition to thelevel of K in ‘Fuji’.Index terms:

O tratamento pré-colheita com aminoetoxivinilglicina ou ácido giberélico preserva a qualidade pós-colheita de ameixas 'Laetitia'

This work was carried out to evaluate the effects of preharvest spraying of Japanese plum trees (Prunus salicina, cv. Laetitia) with aminoethoxyvinilglycine [AVG; at 0, 90, and 120 mg (a.i.) L-1] and giberellic acid [GA3; at 0 and 100 mg (a.i.) L-1] on fruit quality after cold storage. GA3 and AVG were sprayed 28 and seven days before fruit harvesting, respectively. Fruit quality was assessed after 22 days of cold storage (0.5 oC/92% RH), followed by five days of shelf life (23 oC/60% RH). There was no interaction between AVG and GA3 for all fruit quality attributes. Preharvest spraying with GA3 and AVG increased flesh firmness, and delayed the increased of soluble solids content of the fruits. AVG delayed skin color evolution and reduced decay incidence. The treatment with GA3 caused high titratable acidity. There was a linear response to AVG doses considering the maintenance of flesh consistence and skin color, and on reduction of decay incidence.