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Representando apenas 10% do consumo, a produção brasileira de peras está estagnada a mais de 20 anos em torno de 20 mil toneladas anuais, decorrentes da baixa área cultivada em função das baixas produtividades e consequente baixa rentabilidade. Uma das principais causas de baixa produtividade de pomares de pereiras é a baixa frutificação efetiva, isto deve-se a problemas no processo de polinização e fecundação das flores. O objetivo deste trabalho foi avaliar o processo de frutificação natural da pereira ‘Rocha’, identificando a taxa de polinização aberta, partenocárpica natural e autopolinização, bem como avaliar potenciais técnicas para aumento de frutificação da pereira ‘Rocha’, nas condições edafoclimáticas de Vacaria, RS. Foram utilizadas pereiras ‘Rocha’ enxertadas sobre o portaenxerto de marmeleiro ‘BA 29’ com cultivar polinizadora ‘Packham’s Triumph’ disposta em filas inteiras, na proporção de uma fila da polinizadora para cada três da cultivar ‘Rocha’. Avaliou-se a taxa de frutificação natural do pomar, de autofecundação e partenocarpia natural, o efeito da polinização controlada e polinização via água com pólen de ‘Packham’s Triumph’ e Pyrus calleryana, o efeito dos fitorreguladores GA3, GA4+7 + BA, TDZ, AVG, sobre a frutificação efetiva, produtividade e qualidade de frutos da pereira ‘Rocha’. Verificou-se que as taxas de autopolinização e partenocarpia natural da pereira ‘Rocha’, bem como o arranjo implantado não proporcionam produções comercialmente rentáveis. As condições climáticas durante a floração, embora não favoráveis, permitem a fecundação e frutificação da pereira ‘Rocha’ nas condições de estudo. A pulverização de 20 mg L-1 de TDZ aumenta frutificação efetiva e a produtividade da pereira ‘Rocha’.

ABSTRACT Graft incompatibility is one of the main factors limiting european pear production in Brazil. At present, there is no clear indication of the best combination(s) of european pear cultivars and quince rootstocks for graft compatibility. The study evaluated the graft compatibility for combinations of european Abbè Fetel, Rocha and Williams pear cultivars grafted onto the EMC quince rootstock. The experiment was performed in a commercial european pear orchard in the Urupema municipality, in State of Santa Catarina, during the 2011/12, 2012/13 and 2013/14 growing seasons. The plant growth variables comprised the section increment (mm) in the trunk diameter in the graft union region of cultivars and rootstocks; difference in the diameter of the graft for cultivars and rootstocks; “translocated” incompatibility; “located” incompatibility and the vascular connection in the graft union region, which was assessed by immersing the bases of the plants in a 0.08% succinic acid solution. There were “located” and “translocated” incompatibility between the european Williams pear cultivar and the EMC rootstock based on the vascular discontinuity in the graft union region, which prevented the translocation of succinic acid stain. Thus, the Williams/EMC combination is considered incompatible and it is not recommended for use in commercial orchards. The Rocha/EMC and Abbè Fetel/EMC are considered partially incompatible combinations and showed good development eight years after planting.

Perry pear polyphenols were characterized in fruit, juice and pomace for two cultivars and at two maturity stage. Cell walls were characterized only in fruits and pomaces. The phenolic contents and compositions of fruits did not change during overripening. However, their extraction to juice was modified. Juices of ripe fruits contained 38% (Plant de Blanc) and 28% (De Cloche) of initial polyphenols, whereas overripe pear juices contained only 26% and 15% respectively. Thus, procyanidins had more affinity for cell walls after overripening. Pear cell walls from De Cloche cultivar lost arabinose and galactose from pectic side chains during overripening promoting non-covalent interactions between procyanidins and cell walls. [ABSTRACT FROM AUTHOR]

Application of edible coatings is a suitable method to maintain the quality and reduce post-harvest losses in fresh vegetables and fruits. Pear fruits being climacteric have a short shelf life, and coating is considered as one of the most popular techniques to prolong its shelf life.The present study evaluates the effect of optimized edible coatings containing soy protein isolate (SPI) in combination with additives like hydroxypropyl methylcellulose (HPMC) and olive oil on 'Babughosha' Pears ( Pyrus communis L.) stored at ambient temperature (28 ± 5 °C and 60 ± 10% RH). Four different coatings optimized by response surface methodology study were used in the present experiment. The results of the present study shows that the optimized edible coatings help retain the firmness of fruits and lowered the moisture loss. The tested combination of coating could also withhold the levels of ascorbic acid, chlorophyll and sugar contents in the treated fruits. Activities of enzymes associated with fruit softening (β-galactosidase, polygalacturonase, pectin methyl esterase) showed delayed peaks. Amongst all treatments, T1 (SPI 5.0%, HPMC 0.40%, Olive oil 1%, Potassium sorbate 0.22%) and T2 (SPI 5.0%, HPMC 0.40%, Olive oil 0.98% Potassium sorbate 0.20%) were found to have pronounced effect on retention of nutritional quality in pears. Observations of shelf-life extension established that T2 (SPI 5.0%, HPMC 0.40%, Olive oil 0.98% Potassium sorbate 0.20%) was successful in extending shelf-life of pear fruits up to 15 days, as compared to 8 days for untreated pear fruits. [ABSTRACT FROM AUTHOR]

The principles of sustainability in agriculture should be employed, while fighting against diseases and pests in plants, which cause losses in quantity and quality, and environment, human and animal health sensitive farming methods should be followed. In parallel with the development of new agriculture policies that reduce or prohibit the use of pesticides in agricultural production, breeding has become significant among pest and disease management methods. Thus, in this research susceptibility levels against fire blight pre-tested 42 genotypes and 4 cultivars were examined in terms of phenological, pomological and chemical characteristics for two-years. Susceptibility to fire blight, edible quality, attractiveness, fruit thickness, length/diameter, soluble solids content, fruit flesh stone cell amount, fruit flesh hardness and rustiness of genotypes and parental cultivars were evaluated to determine superior ones by weighed ranked method. Full blooming dates, harvest dates and day from full blooming to harvest of analysed genotypes were varied between 25th March - 25th April, 3rd August - 6th October and 109 - 174 days, respectively. Average fruit length was varied from 29.85 mm to 104.61 mm, fruit diameter ranged from 27.76 mm to 76.48 mm, fruit weight was between 12.4 - 292.62 g, and fruit flesh hardness was varied between 5.0 - 10.8 kg/cm2. Average soluble solids content varied from 12.3% to 17.7% and titratable acidity from 0.18% to 0.96%, respectively. According to results, 7 genotypes were considered as potentially superior for further observations. [ABSTRACT FROM AUTHOR]

Superficial scald is the most devastating storage disorder of ‘d’Anjou’ pears ( Pyrus communis L.) and the current commercial controlling method of ethoxyquin (Etq) + controlled atmosphere (CA) storage is not adequate for the fruit produced in hot seasons. In the hot years of 2014 and 2015, ‘d’Anjou’ pears were harvested at commercial maturity and treated with Etq at 2700 mg L −1 , 1-methylcyclopropene (1-MCP) at 0.3 μL L −1 along or in combination with ethylene at 0.3, 0.6, or 1.5 μL L −1 (M+E: 1:0, 1:1, 1:2, and 1:5, respectively), and the combination of Etq plus M+E (1:1), and then stored in CA (1.5 kPa O 2 , <0.5 kPa CO 2 ) at −1.1 °C for 8 months. The non-treated control fruit developed 82% and 100% scald after 4 and 6 months storage, respectively. Etq-treated fruit developed unacceptable level of scald (>10%) after 6 months. M+E (1:0) treatment inhibited ethylene production, prevented scald through decreasing the syntheses of α-farnesene and conjugated trienols, maintained fruit firmness and green color, and reduced decay; however, inhibited ripening capacity following 8 months storage. Compared with M+E (1:0), M+E (1:1 or 1:2) treatments allowed fruit recovering ripening capacity but decreased efficacy on controlling scald; Etq plus M+E (1:1) could control scald <5% for 8 months. M+E (1:5) largely offset the 1-MCP efficacy. In summary, the combination of Etq plus M+E (1:1–2) controls scald, extends storage quality, reduces decay, and allows recovering of ripening capacity of ‘d’Anjou’ pears after long-term CA storage. [ABSTRACT FROM AUTHOR]

The flesh and peel of 19 pear cultivars (8 Tunisian dessert cultivars, 8 European dessert cultivars and 3 French perry pear cultivars) were studied for their phenolic composition. Phenolic compounds were identified by HPLC/ESI-MS 2 and individually quantified by HPLC-DAD. Five classes of polyphenols were present: flavan-3-ols, phenolic acids, flavonols, anthocyanins and simple phenolics (hydroquinones). The total phenolic content ranged between 0.1 g/kg Fresh Weight (FW) (‘Conference’ cultivar) and 8.6 g/kg FW (‘Plant De Blanc’ cultivar) in the flesh and between 1.6 g/kg FW (‘William vert’ cultivar) and 40.4 g/kg FW (‘Arbi Chiheb’ cultivar) in the peel. Procyanidins, analyzed after thioacidolysis, were the main phenolic compounds in all pear cultivars either in the pulp or the peel, their constitutive units being essentially (−)-epicatechin. Tunisian dessert pears and French perry pears are richer in procyanidins with very high degree of polymerization (> 100) for Tunisian pears. Peel procyanidins were less polymerized (from 4 to 20). Pear peel phenolic profile was more complex especially for Tunisian cultivars, with flavonols and in some cultivars anthocyanins. [ABSTRACT FROM AUTHOR]

A cultura da pereira (Pyrus communis) possui grande potencial de expansão no sul do Brasil devido às condições climáticas e solo. A carência de informações a respeito da(s) melhor(es) combinação(ões) de cultivares copa de pereira europeia e portaenxertos, quanto ao aspecto vegetativo e potencial produtivo, tem limitado o cultivo. O objetivo do trabalho foi avaliar a influência de cultivares copa de pereira europeia e portaenxertos de marmeleiro (Cydonia oblonga) sobre o vigor e variáveis de plantas. Os experimentos foram conduzidos em pomares comerciais da cidade de Fraiburgo, Estado de Santa Catarina, durante os ciclos de cultivo 2008/09, 09/10 e 10/11. As cultivares avaliadas foram 'Packham's Triumph', 'Santa Maria', 'Rocha' e 'Abbè Fetel' e os portaenxertos de marmeleiro EMC e Adams. O espaçamento de plantio foi de 0,3m entre plantas e 4m entre linhas. As variáveis analisadas foram: a. incremento de altura de plantas (m); b. incremento de volume de copa (m³); c. incremento de diâmetro do tronco da cv. 'copa' (mm); d. incremento de diâmetro do tronco do portaenxerto (mm); e. diferença de diâmetro do tronco entre a cultivar copa e o portaenxerto (mm); f. índice de fertilidade (no de gemas cm-1); g. massa fresca média total acumulada do material vegetativo das três podas de inverno (kg); h. diferença cumulativa entre a massa fresca e a massa seca dos ramos podados (kg). As diferentes combinações de cultivares e portaenxertos interferiram nas diferentes variáveis analisadas. As combinações Abbè Fetel e Rocha sobre marmelo Adams, foram significativamente mais vigorosas em termos de incremento de diâmetro do tronco da cultivar copa, incremento de altura de plantas, incremento de volume de copa e massa fresca média total acumulada do material vegetativo das podas de inverno dos três anos. A combinação Santa Maria sobre marmelo Adams apresentou vigor intermediário significativo de plantas de acordo com o incremento em volume de copa, diferença de diâmetro do tronco entre a cultivar copa e do portaenxerto, sendo mais indicada para uso comercial, devido ao maior equilíbrio proporcionado entre parte vegetativa e produtiva da planta, nas condições edafoclimáticas experimentais do Sul do Brasil.

Observações fenológicas fornecem informações sensíveis para a determinação de como as espécies de plantas respondem às condições climáticas regionais, visando à produção de frutas em diferentes regiões. Assim, o experimento foi conduzido de setembro de 2010 a janeiro de 2011, com o objetivo de caracterizar os estádios fenológicos de pereiras 'Housui' e 'Kousui', cultivadas em clima semiárido do Nordeste do Brasil. Os dados fenológicos (fases) foram coletados no pomar, em observações diárias, desde a aplicação de cianamida hidrogenada (para a quebra de dormência) até o amadurecimento das frutas. Concluíu-se que, em clima semiárido, as pereiras 'Housui' e 'Kousui' concluem seus ciclos fenológicos em 128 dias e 115 dias, respectivamente. Novas pesquisas e mais alguns anos de avaliação serão necessários para gerar um sistema de produção de peras no semiárido nordestino.

During 2012 and 2013 we investigated impact of quinces MA and BA.29 rootstocks on leaf macro- and micronutrients amount at 60 days after full bloom (DAFB) and deviation from optimum percentage (DOP and ΣDOP indexes) of three pear cultivars grown at Cacak region on heavy and acidic soil. Results showed that rootstocks significantly influenced leaf P, Ca and B levels, whereas impact on other leaf nutrients is minor. Quince MA increased leaf P and Ca contents, while BA.29 induced higher leaf B level. Stronger effect than rootstock on leaf nutrients had cultivar, although differences among them for leaf N, Mg and Fe were not significant. Leaf of ‘Abbé Fetel’ on BA.29 had the highest K, Ca, Cu and B amounts, whereas on MA this cultivar had the highest Mn concentration. Also, ‘Abbé Fetel’ alongside with ‘Conference’ on MA had the highest and similar leaf Ca, Cu and Zn amounts. ‘Starking Delicious’ on BA.29 had the highest leaf P content. The DOP index showed high deficiency of K and Mn on both rootstock and Ca on BA.29. Other leaf nutrients tended to have a DOP values close to the optimum level in general. According to ΣDOP index, BA.29 induced better balanced leaf nutritional values as compared to MA for all nutrients. Among cultivars, ‘Abbé Fetel’ on both rootstocks and ‘Conference’ on BA.29 showed the best balanced nutritional values, whereas ‘Starking Delicious’ exhibited a wider imbalance in nutritional values for all nutrients.

O Brasil é um dos maiores importadores mundiais de pera europeias. A falta de material genético adaptado e a deficiência de tecnologias de manejo, bem como o abortamento de gemas florais das cultivares europeias plantadas têm desestimulado os produtores, ocasionando a redução de áreas plantadas. O objetivo deste estudo foi estabelecer uma metodologia de poda verde na cultivar Abate Fetel a fim de aumentar a frutificação e controlar o vigor das plantas. O trabalho foi desenvolvido nos pomares da Frutirol Agrícola Ltda., em Vacaria-RS, nas safras de 2006/2007 e 2007/2008. Utilizou-se a cultivar Abate Fetel sobre dois porta enxertos: marmeleiros 'Adams' e 'EMC'. Foram avaliados os efeitos de dois níveis de poda verde em três diferentes épocas de realização. Os tratamentos consistiram na poda verde, com retirada de 1/3 e 2/3 do comprimento dos ramos do ano, nas épocas de janeiro, fevereiro e março, e uma testemunha, sem poda verde. O delineamento adotado foi o de blocos ao acaso, com parcelas subsubdivididas, com cinco repetições e duas plantas por repetição. Conclui-se que o porta-enxerto 'EMC' induz melhor controle de vigor e aumenta os índices de produtividade para a cv Abate Fetel, comparado com o marmeleiro 'Adams'. A poda verde, com intensidade de 2/3 de retirada dos ramos, independentemente do mês de realização, aumenta a produtividade da pereira cv Abate Fetel.

A two-year field study was conducted to examine the capacity of spontaneous formation of long sylleptic shoots (LSS) in nursery trees of pear cvs. 'Abbé Fétel', 'Conference' and 'Starking Delicious' grafted on Quince MA (MA) and Quince BA 29 (BA 29) rootstocks in a nursery during the first year after bud grafting. Tree height (TH), trunk diameter (TD) - 10 cm above the bud union and number of LSS were measured at the end of each season. The TH was measured from the ground level. The highest number of LSS was developed by cv. 'Abbé Fétel' in both the seasons, and the lowest by cv. 'Starking Delicious'. Tree height and TD were highly significantly affected by the cultivar in both the years and by the rootstock in 2008. The interactions between them did not significantly affect the examined parameters. The study showed that the early growth and syllepsis of pear nursery trees during the first year after bud-grafting were incomparably more affected by the cultivar than by the rootstock under similar weather conditions and on the same soil in a crop rotation system.

Foram conduzidos dois experimentos para estudar o efeito do anelamento e do paclobutrazol na produção e absorção de macronutrientes em pereira cv Packham´s Triumph, no munícipio de São Joaquim-SC, localizado a 1.400 m de altitude, em pomar comercial, utilizando plantas adultas.O delineamento utilizado no primeiro e segundo foi o de blocos casualizados. No primeiro estudo, foram utilizados sete tratamentos: 1)testemunha; 2) 1,5 g /planta do paclobutrazol, aplicados no solo; 3) 3,0 g/planta de paclobutrazol, aplicados no solo; 4 ) 4,5 g/planta de paclobutrazol, aplicados no solo; 5) anelamento simples (1 anel); 6) anelamento duplo realizado (dois anéis), e 7 ) anelamento pleno (um anelamento seguido de outro anelamento no mesmo local após a cicatrização do primeiro). No segundo experimento, os tratamentos foram: 1)-testemunha; 2) 2 g/planta de paclobutrazol, aplicados o solo; 3 ) 4 g/planta de paclobutrazol, aplicados no solo; 4 )-1.000 ppm de paclobutrazol em aplicação foliar; 5 ) 2.000 ppm de paclobutrazol em aplicação foliar; 6 ) anelamento simples, e 7) anelamento duplo. A maior produção foi observada no anelamento pleno e no anelamento duplo. O anelamento teve maior efeito na produção do que o paclobutrazol, e este via solo teve maior efeito do que a aplicação foliar. Os tratamentos não influenciaram nos níveis de nutrientes no fruto, com exceção do potássio. O maior teor de potássio foi encontrado na testemunha que apresentou o maior tamanho de frutos.Two trials was conducted to study the effect of the ring and paclobutrazol in the production and mineral nutrition in pear tree Packham´s Triumph cv, in São Joaquim city, SC, south of Brazil, located in 1,400 m of altitude, in a commercial orchard, using adult plants .The experimental delineation used in the trials was of randomized blocks. In the first trial it was studied 7 treatments : 1) Control, 2) 1,5 g.tree-1 of paclobutrazol applied in soil application, 3) 3,0 g.tree-1 of paclobutrazol applied in soil application, 4) 4,5 g.tree-1 of paclobutrazol applied in soil application , 5) ring (one ring), 6) double ring and 7) full ring (one ring followed by another ring in the same place after cicatrization ).In the second trial, it was studied: 1) control, 2) 2,0 g.tree-1 of paclobutrazol applied in soil application 3) 3,0 g.tree-1 of paclobutrazol applied in soil application, 4) 1000 mg.l -1 paclobutrazol by foliar application, 5) 2000 mg.l -1 of paclobutrazol by foliar application, 6) one ring and 7) double ring .The highest production was observed in the full and double ring. The ring had greater effect in the production and the paclobutrazol soil application had greater effect than the foliar application. The treatments did not influence the nutrients levels in the fruit with exception of the potassium. The highest potassium level was found in the control which showed the biggest fruits.

ABSTRACT ‘Bartlett’ pears from different harvest dates were assessed regarding to cold storage potential and reduction of physiological disorder incidence. Three harvests, the first (HD1), second (HD2), and third (HD3), were carried out at weekly intervals. The pears were assessed after the harvest, with no exposition to the temperature conditioning, after 20, 40, 60, 80, 100 and 120 days at 0 ± 1 °C and 90 ± 5% RH and after three and six days at room temperature (20 ± 1 °C). Fruit from the early harvest (HD1) showed the smallest incidence of physiological disorder during both cold and room temperature storage. The disorder symptoms became apparent in HD1 fruit after 20 days at cold storage followed by three days at 20 °C, whereas HD2 and HD3 fruit showed the symptoms before being kept in a cold room. ‘Bartlett’ pears harvested at 70.75 N flesh firmness can be stored at 0 ± 1 °C for up to 40 days and preferably commercialized within three days, when they reach the firmness for eating. The extension of cold storage as well as the trade period can result in higher physiological disorder incidence and loss of sensorial quality.

Cell walls from flesh, parenchyma cells, stone cells and skin were isolated from ripe and overripe Pyrus communis L. cv “De Cloche” using the phenol-buffer method. Pear polysaccharides were solubilized from cell walls by sequential extractions with aqueous solutions of ammonium oxalate, Na 2 CO 3 , and increasing concentration of NaOH, to explore overripening impact. Cell walls were also differentiated using MIR spectral data. Stone cells contained high levels of xylose and lignin while parenchyma cells had high levels of glucose, uronic acids and arabinose. Sequential extractions revealed that pear pectins had highly branched rhamnogalacturonans and were extremely methylated. Xylans were the main hemicelluloseespecially for stone cells. Cellulose represented about half of all cell walls. This heterogeneous composition of pear affected differently cell wall evolutions and properties. Thus, overripening involved a decrease in arabinose and a loss of pectic side chains mostly from parenchyma cells. Changes in hemicellulose and cellulose were minor. [ABSTRACT FROM AUTHOR]

The effect of composite edible films containing soy protein isolate (SPI) in combination with additives like hydroxypropyl methylcellulose (HPMC) and olive oil on 'Babughosha' pear ( Pyrus communis L.) stored at ambient temperature (28 ± 5 °C and 60 ± 10% RH) was evaluated using Response surface methodology (RSM). A total of 30 edible coating formulations comprising of SPI (2-6%, w/v), olive oil (0.7-1.1%, v/v), HPMC (0.1-0.5%, w/v) and potassium sorbate (0-0.4% w/v) were evaluated for optimizing the most suitable combination. Quality parameters like weight loss%, TSS, pH and titrable acidity of the stored pears were selected as response variables for optimization. The optimization procedure was carried out using RSM. It was observed that the response variables were mainly effected by concentration of SPI and olive oil in the formulation. Edible coating comprising of SPI 5%, HPMC 0.40%, olive oil 1% and potassium sorbate 0.22% was found to be most suitable combination for pear fruit with predicted values of response variables indicated as weight loss% 3.50, pH 3.41, TSS 11.13 and TA% 0.513. [ABSTRACT FROM AUTHOR]

Mealiness causes fruit to develop a soft and dry texture during ripening. No technique currently exists to detect mealiness non-destructively. Two studies were conducted to i) determine the potential of X-ray macro computed tomography (macro-CT) to detect mealiness in ‘Forelle’ pear ( Pyrus communis L.) non-destructively, and to ii) establish histological differences between mealy and non-mealy fruit using X-ray micro computed tomography (micro-CT). Scans were made after 8 and 11 weeks of cold storage at −0.5 °C and at the end of shelf life of 7 days. Total porosity, pore size distribution and connectivity of cells were measured on regions of interest (ROI) cubes excised from the neck and equator of individual fruit. Macro-CT scans showed the presence of structural disorders in the cortex tissue, identified by micro-CT as large pores, in mealy fruit. These pores were already present at the end of cold storage before fruit would become mealy. Statistical differences with fruit which would ripen and become juicy were significant (P < 0.05). The disorder appeared more clearly in the neck than in the equator region of the cortex. At the end of shelf life, porosity was significantly higher in mealy than non-mealy fruit. Micro-CT results confirmed that tissues of mealy fruit were more porous than those of non-mealy fruit, with a larger proportion of pores greater than 56.53 μm. Evidence was found of lysigenous pore formation in mealy fruit. Cells of mealy fruit were larger and oval-shaped while non-mealy fruit cells were more spherical. X-ray computed tomography was shown to be a promising technology for the non-destructive determination of mealiness at an early stage. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Repeated low-dose 1-MCP-applications were evaluated during cold storage of ‘Bartlett’ pear fruit to overcome long-term ripening inhibition of a high dose 1-MCP treatment at harvest. Fruit were exposed to 1-MCP at 0, 0.42, 4.2 or 42 μmol m −3 at harvest in year one, and to 0, 0.42 or 42 μmol m −3 in year two, and then stored in air at 0.5 °C. In year two, fruit exposed to 1-MCP at 0.42 μmol m −3 at harvest were retreated during cold storage once (after 38 days) or twice (after 38 and 68 days), when ethylene production in samples removed from cold storage exceeded 0.014 ηmol kg −1 s −1 within 7 days at 20 °C. 1-MCP was re-applied once at 0.42 or 4.2 μmol m −3 or twice at 0.42 or 4.2 then 42 μmol m −3 . In year one, fruit treatment at harvest with 4.2 or 42 μmol m −3 1-MCP provided similar ripening delay during 120 days in storage followed by 7 days at 20 °C, while fruit treated with 0.42 μmol m −3 1-MCP was not different from the control. In year two, fruit treated at harvest with 0.42 μmol m −3 1-MCP and retreated with 0.42 μmol m −3 (when ethylene production was already high) did not delay subsequent fruit ripening. Fruit treated at harvest with 42 μmol m −3 1-MCP or with 0.42 μmol m −3 at harvest and then +4.2 + 42, had similar peel yellow color, TA and SSC, but higher firmness after 180 days storage, compared to control fruit after 60 days storage. After 180 days storage, the severity of superficial scald, senescent scald and core browning on fruit treated only at harvest with 42 μmol m −3 were lower than on control fruit and similar to on fruit treated with 0.42 μmol m −3 at harvest and then retreated with +4.2 + 42. Therefore, a low dose application of 1-MCP at harvest followed by reapplication with higher doses based on fruit ethylene production capacity after removal from cold storage can extend ‘Bartlett’ pear storage life while allowing ripening to occur after mid-term storage. The efficiency of this procedure will depend on timing and 1-MCP reapplication concentration. [ABSTRACT FROM AUTHOR]

El objetivo del presente trabajo fue establecer algunas propiedades físicas y fisiológicas de desarrollo de la pera (Pyrus communis L.) variedad Triunfo de Viena, producida bajo las condiciones ecuatoriales del clima frío, en los Andes Colombianos. El crecimiento y propiedades de la fruta fueron evaluados en intervalos de 30 días, desde la floración. Las propiedades estudiadas fueron el peso, tamaño de la fruta, firmeza de la pulpa, concentración de sólidos solubles, pH, acidez titulable (% ácido málico) e intensidad respiratoria. La concentración de sólidos solubles y el pH no son propiedades sensibles para determinar el momento apropiado de la cosecha, al presentar valores constantes y de baja dispersión. El fruto presenta forma esférica y su área superficial es función directa del peso de la fruta. La firmeza de la pulpa, la acidez titulable (AT) y la intensidad respiratoria, decrecen en la medida que se desarrolla la pera, presentando valores en el momento de la cosecha de 67,82 N para la firmeza, acidez titulable de 0,24% e intensidad respiratoria de 29,60 mg CO2 kg-1 h-1. Los sólidos solubles (SS) y la relación SS/AT se incrementan en la medida que el fruto va madurando. En el momento de la cosecha los frutos presentan un valor de SS de 12,0ºBrix, una relación SS/AT de 49,36 y un pH de 3,94.The objective of the present work was to determine some physical and physiological properties of pear development cv. Triunfo de Viena, produced under the equatorial cold at the Colombian Andes. The fruit growth was evaluated at 30 days intervals starting at its full bloom. The studied properties were fruit weight, size, flesh firmness, soluble solids concentration, pH, titratable acids (% malic acid) and respiratory rate. The soluble solids concentration and pH are not sensible properties to determine the appropriate harvest time, presenting constant values and low dispersion. The fruit presents spherical form and its superficial area is a direct function of the fruit weight. The flesh firmness, titratable acids (TA) and respiratory rate, decrease when the pear grows, presenting harvest values of 67,82 N for flesh firmness, titratable acidity of 0,24% and respiratory rate of 29,60 mg CO2 kg-1 h-1. The soluble solids concentration (SS), and the relation SS/TA increase at the fruit ripening. At harvest time the fruits present SS about 12,0ºBrix, relation SS/TA of 49,36 and pH 3,94.

Pyrus communis 'Rocha' is an economically important crop very susceptible to the pathogenic fungus Stemphylium vesicarium, the causal agent of brown spot disease. Knowledge on the complexity of mechanisms responsible for resistance to S. vesicarium infection is necessary for definition of strategies to improve defence responses in susceptible cultivars. To investigate the molecular mechanisms behind Pyrus communis defence responses to S. vesicarium, a 6624 (3312 × 2) cDNA microarray was constructed to identify genes differentially expressed between a resistant/tolerant cultivar ('Ercolini') and a susceptible cultivar ('Rocha'). Both cultivars were compared to evaluate their genetic background differences prior to inoculation (T0h) and transcriptional changes along a time course infection with S. vesicarium (T6h and T24h). Two cDNA libraries, from 'Rocha' and 'Ercolini' pear cultivars, spotted in the microarray resulted on 146 differential expressed genes. Transcriptome analysis revealed several transcripts related to stress and defence, namely peroxidases, 3-dehydroquinate dehydratase/shikimate 5-dehydrogenase, thiazole biosynthetic enzyme, serpins, cytochromes P450, 2-methyl-6-phytylbenzoquinone methyltransferase, 6-phosphogluconate dehydrogenase, polyneuridine-aldehyde esterase precursor, lipoxygenases and PR proteins. The results suggest that resistance/tolerance of 'Ercolini' cultivar may result from the rapid activation of defence mechanisms while in 'Rocha' cultivar the defence mechanisms may be activated too late for inducing an efficient response to infection by S. vesicarium. Cell wall strengthening and biosynthesis of antifungal compounds may constitute efficient physical and chemical barriers to S. vesicarium infection and priming emerges as a putative mechanism of resistance/tolerance. The evidence gathered combined with knowledge on host/endophyte signalling in mycorrhiza leads us to suggest priming as a measure to brown spot disease control in 'Rocha' pear cultivar through symbiosis with mycorrhizal fungi in order to anticipate and induce a more efficient activation of defence mechanisms. Also the thiazole biosynthetic enzyme and the serpins appears as potential candidates for the development of molecular markers for resistance to infection. [ABSTRACT FROM AUTHOR]

Polyamines (PAs) are small molecules necessary for pollen maturation and tube growth. Their role is often controversial, since they may act as pro-survival factors as well as factors promoting Programmed Cell Death (PCD). The aim of the present work was to evaluate the effect of exogenous PAs on the apical growth of pear ( Pyrus communis ) pollen tube and to understand if PAs and reactive oxygen species (ROS) are interconnected in the process of tip-growth. In the present study besides natural PAs, also aryl-substituted spermine and methoctramine (Met 6-8-6) analogs were tested. Among the natural PAs, Spm showed strongest effects on tube growth. Spm entered through the pollen tube tip, then diffused in the sub-apical region that underwent drastic morphological changes, showing enlarged tip. Analogs were mostly less efficient than natural PAs but BD23, an asymmetric synthetic PAs bearing a pyridine ring, showed similar effects. These effects were related to the ability of PAs to cause the decrease of ROS level in the apical zone, leading to cell death, counteracted by the caspase-3 inhibitor Ac-DEVD-CHO (DEVD). In conclusions, ROS are essential for pollen germination and a strict correlation between ROS regulation and PA concentration is reported. Moreover, an imbalance between ROS and PAs can be detrimental thereby driving pollen toward cell death. [ABSTRACT FROM AUTHOR]

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Composition of tocochromanols was studied in seeds recovered from eight pear ( Pyrus communis L.) cultivars, six dessert and two interstock, grown in a single environment. Four tocopherol (T) homologues, namely α, β, γ and δ, were quantified in all tested samples by RP-HPLC/FLD method. The RP-UPLC-ESI/MS n analyses confirmed the identity obtained by the RP-HPLC/FLD method and the additional trace amounts of two tocotrienol homologues, α and γ, were detected. The concentration of individual tocopherol homologues in seeds of different pear cultivars, expressed in mg/100 g dry weight basis, dw, was in the follow range: 4.00–5.98 (α-T), 0.11–0.31 (β-T), 32.06–42.07 (γ-T) and 0.43–1.21 (δ-T). The γ-T was the main tocopherol homologue identified in pear seeds and constituted approximately 87% of the total detected tocochromanols. Only minor variation of the ratio of individual tocopherol homologues (α, β, γ and δ; 31:1:234:5) was observed in all studied samples. [ABSTRACT FROM AUTHOR]

The primary purpose of this study was to determine the effects of pre-harvest application concentration, frequency, and timing of harpin β protein on quality attributes, nutrient uptake, and susceptibility to physiological disorders in 'Bartlett' and 'd′Anjou' pears. Split applications of 1.5 mg L−1 harpin at 30 + 7 d before harvest (30 +7 DBH) resulted in higher fruit firmness (FF) and peel chlorophyll content with a lower soluble solids content in 'Bartlett' pears at harvest compared to the control, but not in 'd′Anjou' pears. This treatment reduced the ethylene production rate (EPR) and FF loss of 'Bartlett' pears at the initial 3 months of regular-air (RA) storage. Extending the storage periods to 5 months, a high EPR with low incidence of senescent disorders was observed after storage and during ripening, respectively. Increasing the application concentration of harpin from 1.5 to 10 mg L−1 did not further affect the quality of 'Bartlett' pears. Early application of harpin between full bloom (FB) and 2 months after full bloom (2 MAFB) repeated up to 3 times resulted in high FF and green color of 'd′Anjou' pears at harvest, but not in 'Bartlett' pears. A single application of harpin 2 MAFB to 'd′Anjou' trees provided the greatest reduction the losses in FF and green color, extend storage life, and suppress the development of superficial scald. No difference was observed in nutrient uptake in either cultivar when harpin was sprayed at 30 + 7 DBH. Spraying harpin once at 1 MAFB, once at 2 MAFB, and three times at FB+ 1 MAFB+ 2 MAFB resulted in low-boron 'Bartlett' and low-calcium 'd′Anjou' pears. Fortunately, harpin-treated pears with lower B or Ca levels did not result the quality deterioration and development of disorders. In conclusion, harpin has the potential to improve fruit quality, but recommended timing varies by cultivar: spraying 1.5 mg L−1 harpin at 2 MAFB improved the quality of 'd′Anjou' pears, whereas quality of 'Bartlett' pears was improved by applying harpin at 30 + 7 DBH. • 1.5 mg L−1 Harpin β protein was sufficient to improve the quality of pears. • Spraying harpin at 30 + 7 d before harvest improved the quality of 'Bartlett' pears. • Spraying harpin once at 2 MAFB improved the quality of 'd′Anjou' pears. • Harpin suppressed the development of disorders in 'Bartlett' and 'd′Anjou' pears. • Harpin affected the boron or calcium uptakes in pears. [ABSTRACT FROM AUTHOR]

Chlorophyll degradation is a key component of the changes in pigment composition that typically occur in fruit peel at the onset of ripening. In this study, two pear cultivars, which are different in color development patterns, were used to clarify the molecular mechanism of chlorophyll degradation during ripening. Fruit was harvested and stored at 1 °C for cold treatment and then transferred to 20 °C for ripening. ‘Le Lectier’ pears turned yellow during ripening with concomitant loss of chlorophylls a and b , and carotenoids. In contrast, ‘La France’ pears stayed green even when fully ripe. In this cultivar, chlorophyll and carotenoid contents did not change significantly. Ethylene was normally produced in ‘La France’ pears, indicating that the stay-green characteristics do not result from an inability of the fruit to produce ethylene. The expression levels of the chlorophyll degradation related genes, including chlorophyllase 1 , pheophorbide a oxygenase , non-yellow coloring 1 , and NYC1-like were lower in ‘La France’ than those in ‘Le Lectier’ pears. Suppression of these genes in ‘La France’ pears might be related to the stay-green characteristics when fully ripened. [ABSTRACT FROM AUTHOR]

'Bartlett' pears are resistant to ripening after harvest. Ethylene and temperature conditioning have been successfully used to stimulate fruit ripening with improved eating quality over non-conditioned fruit. However, few studies have evaluated the effect of different conditioning treatments on the sensory attributes of the fruit. In this study, we compared a descriptive sensory evaluation with the chemical composition of 'Bartlett' pears after the fruit were exposed to the following conditioning treatments: 2 d 100 μl L-1 ethylene, 14 or 7 d at 0 °C, 7 or 3 d at 10 °C, or untreated control at 20 °C. Fruit were softened to 27, 18 and 9 N firmness before evaluation. At 9 N, fruit conditioned at 0 °C produced high levels of esters, and fruit conditioned at 0 °C for 14 d also were high in sweet taste and fruity flavor attributes. Fruit treated at 10 °C had lower concentrations of esters, but fruit treated at 10 °C for 3 d was high in sweet taste perception. Ethylene treated fruit produced low levels of esters and high levels of aldehydes and were associated with apple aroma, similar to the untreated control fruit. Water soluble pectin levels were highly and positively correlated with juiciness and sweetness and negatively correlated with firmness, crunchiness, and grittiness. Future studies should determine whether consumer liking of 'Bartlett' pear fruit is also influenced by conditioning treatment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fruits of giant-fruit pear mutant weigh twice of original cultivar ‘La France’. [•] This mutant showed fruit-specific genome duplication and enlargement of fruit cells. [•] Mutant fruits exhibited higher titratable acidity than those of original cultivar. [•] Starch and hemicellulose contents were lower in this mutant than original cultivar. [•] This mutation may have occurred by chimeric polyploidization or endoreduplication. [Copyright &y& Elsevier]

Pears, besides apples, are also popular fruit species at the Polish fruit market. It is connected not only with their delicious taste but, among others, year-round availability at the market. The research objective was to determine and compare the basic chemical composition, i.e. dry matter, N-compounds (total), mineral elements (total), dietary fiber and easily hydrolyzed sugars (NFE), vitamin C as well as mineral content of: Mg, K, Na, Ca, Mn and Fe in the flesh and the peel of pears of the following cultivars: ‘Bonkreta Willimsa’, ‘Concorde’, ‘General Leclerc’, ‘Faworytka’, ‘Komisówka’, ‘Konferencja’ and ‘Lukasówka’ harvested in 2009 and 2010. In all the analyzed pear cultivars, nutrient concentration appeared to be higher in the fruit peel compared to the flesh. The pears from the ‘Concorde’cv (average 23% f.m. –dry matter, 0.5% f.m. – N-compounds, 19.1% f.m. – NFE) and ‘Lukasówka’ cv. (average 23.1% f.m. – dry matter., 0.5% f.m. – N-compounds, 19.2% f.m. – NEF). The highest fiber content was determinated in friuts ‘Faworytka’ (average peel – 7.2% f.m., flesh – 0.7% f.m..).Whereas the highest concentration of vitamin C was observed in the peel and flesh of ‘Concorde’ (8.0–7.8 mg 100-1 f.m.), ‘Faworytka’ (7.6–7.4 mg 100-1 f.m.) and ‘Lukasówka’ (8.4–8.0 mg 100-1 f.m.). While considering a mineral compound concentration, the richest were ‘Concorde’ cultivar pears (peel – 0.4% f.m.; flesh – 0. % f.m.). Out of the studied pear cultivars the lowest concentration of these elements was established in the ‘Conference’ and ‘Komisówka’ cultivars. There was determined the highest content of K in fruits of ‘Bonkreta Williamsa’, ‘Concorde’, ‘Komisówka and ‘Konferencja, Na – ‘Faworytka’ and ‘Lukasówka, Ca – ‘Concord’ and ‘Konferencja’, Mg – ‘Komisówka’, Mn – ‘Bonkreta Williamsa’ and ‘Concorde’ and Fe – ‘Concorde’. In most investigated pears, there was noted a higher concentrations of nutrients in fruit produced in 2009 year compared to 2010.

The pear (Pyrus communis) culture offers a great expansive market opportunity in southern Brazil, according to climatic conditions and soil. However, there are still some barriers that prevent satisfactory economic production, such as lack of knowledge about the best combinations of cultivars and rootstocks. The objective of the study was to evaluate the influence of European pear cultivars and quince (Cydonia oblonga) rootstocks on the plants vigor variables. The experiments were carried out in commercials orchards in Fraiburgo Municipality, Santa Catarina state, during the crop season of 2008/09, 09/10 and 10/11. The cultivars evaluated were 'Packham's Triumph', 'Santa Maria', 'Rocha' and 'Abbè Fetel' and the quince rootstocks EMC and Adams. The cultivars and rootstocks combinations were conducted in a spacing of 0.3mx4m between plants and rows, respectively. The vigor variables evaluated were, a. plants height increment (m); b. canopy volume increment (m³); c. truck diameter increment of the cultivars canopy (mm); d. truck diameter increment of rootstocks (mm); e. difference between the trunk diameter of cultivars canopy and rootstock (mm); f. fertility index (buds cm-1); g. total cumulative average of fresh weight of pruned branches (kg); and h. cumulative difference between the fresh and dry weight of pruned branches (kg). All combinations evaluated affected the vegetative parameters of the European pear cultivars. The combinations Abbè Fetel and Rocha grafted on Adams quince rootstocks are significant more vigorous according to increment of cultivars canopy truck diameter, plant height increment, cultivars canopy volume increment and cumulative average weight of pruned branches, when compared with others combinations. The combination Santa Maria grafted on Adams quince rootstock showed significant intermediate vigor according to cultivar canopy volume increment, truck diameter of cultivar canopy and, truck diameter of rootstock. This combination presented a better proportion amongst the vigor variables and can be indicated for commercial production according to the experimental edafoclimatic conditions of southern Brazil. [ABSTRACT FROM AUTHOR]

Abstract: The germplasm pear bank in north-western Spain includes 221 accessions collected in the region between 1978 and 1981. Four reconstructed populations (RPPs) were detected by simple sequence repeats (SSRs) using a Bayesian method, two of which included French and English cultivars introduced to north-western Spain after reconquest by the Muslims in the 10th century. We studied 22 morphological and 15 phenological characteristics. We used principal component and cluster analysis to identify and classify the main origins of variability, these being flowering time, size and shape of fruit, time of harvesting, percentage of russeting and firmness of the flesh. Genetic differentiation between reconstructed populations, detected by a Bayesian method using SSRs, was also found in morphology, though with a great diversity inside each RPP that overlapped the main RPPs. This was consistent with the excellent quality of the reference cultivars apparently involved in the origin of the two main RPPs, ‘Mantecosa Hardy’ and ‘Williams’, suggesting that the contribution of foreign cultivars and subsequent selection by farmers have led to common phenotypic characteristics in both main groups. The introduction of cultivars from France and the United Kingdom could have occurred before 1746, when the first references to local cultivars related to both main RPPs were made. Furthermore, hybridisation with local species could explain part of the variability detected, which can be exploited for breeding programmes and local productions, nowadays focused on a reduced number of cultivars. [Copyright &y& Elsevier]

Several old cultivars, and breeding clones of European pear Pyrus communis L. originating from Belgium, England, Sweden, and Switzerland were evaluated for their resistance/susceptibility to fire blight. Studies were carried out during three consecutive years 2007-2009 in the greenhouse of Warsaw University of Life Sciences, Poland. Strain 691 of Erwinia amylovora was used for artificial infection of plants. Genotypes included in this study considerably varied in their resistance to fire blight. The most resistant was the old English cultivar 'Hessle'. The other two genotypes, i.e., 'Gränna Rödpäron' originating from Sweden, and Pyrus communis FG 1606 from Switzerland were included in a group of low susceptible ones. The most susceptible were Cra Py H 18, Cra Py V 22 and Cra Py W 14 from Belgium. [ABSTRACT FROM AUTHOR]

Abstract: This work sets out to examine the effectiveness of a number of cytokinins or products with cytokinin-like activity, with and without additional sprays of gibberellins or leaf plucking, on the production of feathers (sylleptic shoots) on trees of the European pear cultivar ‘Comice’ in a fruit tree nursery. It covers the results from three successive years experimentation. In year 1, unsprayed trees of ‘Comice’/quince C (QC) had an average of 1.6 useful feathers per tree. Three applications of 1000–2000mgL−1 benzyladenine (BA) followed by three applications of 400mgL−1 GA4+7 resulted in over a fourfold increase in the number of feathers and a fivefold increase in the total length of feathers. Thidiazuron (TDZ) applications of 30–40mgL−1 followed by three applications of 400mgL−1 GA4+7 also resulted in an increase in feathering but were not as effective as BA sprays. Both spray treatments resulted in more spines on the trees. In year 2, feathering of ‘Taylor''s Gold Comice’/QC was enhanced by three BA sprays at 1500mgL−1, followed by three sprays of GA4+7 at 400mgL−1. Leaf plucking tended to improve feathering in the absence of GA4+7. BA sprays were more effective than sprays of TDZ at the concentrations used (30 and 60mgL−1). Sprays of GA4+7 without the use of cytokinins also stimulated feathering. Thorniness was linked with the use of GA4+7, not the cytokinins. In year 3, feathering of ‘Comice’/QC was enhanced by combinations of BA and GA (GA3 or GA4+7) sprays (four sprays of each applied sequentially) and these resulted in large, well-feathered trees. Thorniness was associated with the use of gibberellins rather than cytokinins. Thorniness was not reduced by the use of GA3 over the use of GA4+7; in fact it was made worse. However, GA3 was more effective at inducing feathering than GA4+7, so a similar thorniness score and feathering could be achieved by using 200mgL−1 GA3 as achieved with 400mgL−1 GA4+7. GA3 is additionally a cheaper product. Sprays of GA without the use of BA also stimulated feathering, although the height of these feathers in the tree were too high for commercial use because these sprays of GA were applied four weeks later than the BA sprays. Therefore, GA sprays applied earlier in the tree development may be sufficient to feather ‘Comice’ in the absence of BA. [Copyright &y& Elsevier]

The article focuses on a study which examined the impact of postharvest 1-methylcyclopropene (1-MCP) treatment timing on the ripening and physiological disorders of Bartlett pears during cold storage and shelf-life. Bartlett pears were obtained from a commercial orchard in Ontario. At the time of harvest, no measurable ethylene production was observed. The fruits also produced less ethylene than untreated fruit during holding and after cold storage for four months.

Abstract: To reduce the use of fungicides, biological control with yeasts has been proposed in postharvest pears. Most studies of antagonists selection have been carried out at room temperature. However, in regions like North Patagonia where fruits are stored at −1/0°C during 5–7months the selection of potential antagonist agents must be carried out at low temperature. In this study, 75 yeast cultures were isolated from healthy pears from two Patagonian cold-storage packinghouses. Aureobasidium pullulans, Cryptococcus albidus, Cryptococcus difluens, Pichia membranifaciens, Pichia philogaea, Rhodotorula mucilaginosa and Saccharomyces cerevisiae yeast species were identified. Additionally, 13 indigenous isolates of Penicillium expansum and 10 isolates of Botrytis cinerea were obtained from diseased pears, characterized by aggressiveness and tested for sensitivity to postharvest fungicides. The yeasts were pre-selected for their ability to grow at low temperature. In a first biocontrol assay using the most aggressive and the most sensitive isolate of each pathogen, two epiphytic isolates of A. pullulans and R. mucilaginosa were the most promising isolates to be used as biocontrol agents. They reduced the decay incidence by P. expansum to 33% and the lesion diameter in 88% after 60days of incubation in cold. Foreign commercial yeast used as a reference in assays, only reduced 30% of lesion diameter in the same conditions. Yeasts were not able to reduce the incidence of B. cinerea decay. The control activity of the best two yeasts was compared with the control caused by the fungicides in a second bioassay, obtaining higher levels of protection against P. expansum by the yeasts. These two regional yeasts isolates could be promising tools for the future development of commercial products for biological control. [Copyright &y& Elsevier]

To find an alternative tool to chemical analysis for assessing the nitrogen (N) nutritional status, the SPAD-Minolta-502 portable chlorophyll meter was tested in one- to three-years-old 'Rocha' pear trees fertilized with 0, 10, 20 and 40 kg N ha-1 year-1. SPAD readings in the third and fourth fully expanded leaves were as responsive to N fertilization as leaves sampled for foliar chemical analysis (medium third of one-year-old shoots), but individual leaves showed heterogeneous chlorophyll patterns. SPAD readings in leaves sampled at 60 and 110 days after full bloom (DAFB) related linearly with leaf N concentration but significant relationships could also be obtained later. Assuming an optimum leaf N concentration of ≥20 g kg-1 dry weight, SPAD readings ≥33 in leaves sampled at 60-110 DAFB corresponded to a good nutritional N status of young pear trees, making this diagnostic technique more practical, non-destructive and inexpensive, compared with chemical leaf analysis. [ABSTRACT FROM AUTHOR]

We present a segmented partial least squares (PLS) prediction model for firmness of ‘Rocha’ pear (Pyrus communis L.) during fruit ripening under shelf-life conditions. Pears were collected from three different orchards. Orchard I provided the pears for model calibration and internal validation (set 1). These were transferred to shelf-life in the dark at 20±2°C and 70% RH, immediately after harvest. External validation was performed on the pears from the other two orchards (sets 2 and 3), which were stored under different conditions before shelf-life. Fruit was followed in the shelf-life period by visible/near infrared reflectance spectroscopy (Vis/NIRS) in the range 400–950nm. The correlation between firmness and the reflectance at some wavelength bands was markedly different depending on ripening stage. A segmented partial least squares model was then constructed to predict firmness. This PLS model has two segments: (1) unripe and ripening/ripe pears (high firmness); (2) over-ripe pears (low firmness). The prediction is done in two steps. First, a full range model (full model) is applied. When the full model prediction gives a low firmness value, then the over-ripe model is applied to refine the prediction. The full model is reasonably significant in regression terms, robust, but allows only a coarse quantitative prediction (standard deviation ratio, SDR=2.48, 1.50 and 2.40 for sets 1, 2 and 3, respectively). Also, RMSEP%=139%, 91% and 56%, indicating large relative errors at low firmness values. The segmented model improved moderately the correlation, and the values of RMSEC, RMSEP and SDR; it improved significantly the RMSEP% (29%, 55% and 31%), providing an improvement of the relative prediction errors at low firmness values. This method improves the ordinary PLS models. Finally, we tested whether chlorophyll alone was enough for a predictive model for firmness, but the results showed that the absorption of chlorophyll alone does not explain the performance of the PLS models. [Copyright &y& Elsevier]

The residue levels of fludioxonil (FLU) were determined in Coscia pear following a 1-, 2- or 4-min dip in an aqueous mixture of FLU containing 300 or 100 mg l-1 (active ingredient, a.i.) at 20 and 50°C, respectively, with or without 2% soy lecithin. The efficacy of heat treatment with water and FLU mixtures was investigated on artificially inoculated pears for the control of post-harvest decay caused by blue (Penicillium expansum Link) and grey (Botrytis cinerea Pers. ex Fr.) mould. Treatment with 300 mg l-1 FLU at 20°C increased residues significantly when treatment time rose from 1 to 2 min; no further increase was recorded when dip time raised from 2 to 4 min. FLU residue rates were unaffected by treatment time when 300 mg l-1 a.i. was applied in combination with lecithin at 20°C. While treatment with 100 mg l-1 a.i. at 50°C for 1 and 2 min resulted in similar residue levels, significantly higher residues were detected when dip time increased from 1 to 4 min. Co-application of lecithin significantly decreased FLU residues with respect to fruit treated with FLU alone. Treatments with FLU at 20 or 50°C effectively controlled decay over 10 days of incubation. While co-application of lecithin did not affect the efficacy of FLU at 300 mg l-1and 20°C, treatment efficacy decreased when lecithin was applied in combination with 100 mg l-1 FLU and 50°C for 4 min and to a greater extent when dip time was 1-2 min. [ABSTRACT FROM AUTHOR]

The current understanding of the RNase-mediated Gametophytic Self-Incompatibility (GSI) system in pears is presented. A practical outcome of GSI research is the ability to S-genotype cultivars molecularly. In Israel the main pear cultivar is ‘Spadona’; ‘Cocsia’, ‘Gentile,’ and ‘Spadochina’ serve as its pollenizers. However, yields are relatively low, probably, at least in part, because of genetic semi-compatibility, which causes rejection of half of the pollen grains that reach the ‘Spadona’ flowers. The wild pear Pyrus syriaca, which is endemic to Israel, flowers in parallel to the cultivated European pear varieties, and is expected to be compatible with them. We are currently examining P. syriaca trees in the northern part of Israel, to see if they could serve as efficient pollenizers for the cultivated pears in Israeli orchards. [ABSTRACT FROM AUTHOR]

The majority of European pears (Pyrus communis L.) show at some extent resistance to ripening after harvest. Low temperatures and/or ethylene treatments have to be applied to counteract this behavior. This review provides the main protocols that have been used experimentally to ripen European pears grown in the U.S. and summarizes important aspects to understand the ripening physiology of this fruit. Many factors interacting with pear ripening are discussed including, cold storage, controlled atmosphere storage, ethylene treatment, cultivar differences, preharvest temperature, growing region, harvest maturity, storage time and ripening temperature, cooling and warming of fruits, treatments to inhibit ripening, and plant growth regulators. [Copyright &y& Elsevier]

Clones of the 'Ankara' pear (Pyrus communis L.) cultivar, which is a winter-type of European pear, were investigated in terms of morphological and chemical characteristics, and sensory analyses, in the Ankara (Turkey) region in 2001, 2002, and 2003. Fruit weight, length, and diameter; core diameter; skin and flesh color; flesh firmness; soluble solids content; titrable acidity; pH; grittiness; melting degree in the mouth (buttery flesh); flavor; texture; and appearance were determined in 40, 17, and 26 clones in 2001, 2002, and 2003, respectively. Two clones #5 and #6, were selected as superior clones of 'Ankara' pear in 16 clones, which were not alternate bearing during 3 years. The average fruit weight, fruit length, and diameter of clone #5 were 225.5 ± 32.8 g, 69.6 ± 1.3 mm, and 73.7 ± 3.4 mm, respectively. The same measurements of clone #6 were 202.1 ± 2.0 g, 65.9 ± 0.1 mm, and 72.0 ± 0.2 mm, respectively. Grittiness was low, and texture and appearance were fine in these clones over the course of 3 years. [ABSTRACT FROM AUTHOR]

Abstract: Effects of the synthetic auxin 2,4-dichlorophenoxy-propionic acid (2,4-DP) on 1-aminocyclopropane-1-carboxylate (ACC) synthase and oxidase gene expression in ‘La France’ and aroma production in ‘Bartlett’ pears (Pyrus communis L.) were investigated. In non-stored, non-treated ‘La France’ fruit, the accumulation of ACC synthase (ACS) and ACC oxidase (ACO) transcripts was not observed. In 2,4-DP treated ‘La France’ fruit, the level of mRNAs hybridized with ACS4 probe increased strongly while ACS1, ACS3, and ACO1 mRNA levels were similar between 2,4-DP treated fruit and stored non-treated fruit. The result indicates that ACS4 may be an ACC synthase gene which is induced by auxin in pears. Thirty-eight volatile compounds were detected from ‘Bartlett’ pears. The composition and amount of aroma volatiles were similar between 2,4-DP treated fruit and stored non-treated fruit. Esters were the most prevalent compounds and butyl-, ethyl-, and hexyl acetate were produced in the largest amounts. In non-stored, non-treated fruit, aldehydes constituted a high percentage of the total volatiles detected, although the amount of total volatiles detected was relatively low. Internal browning in 2,4-DP treated ‘Bartlett’ fruit developed on the tree within 30 days of application. Possible effects of pre-harvest ethylene, carbon dioxide, and temperatures, are discussed. [Copyright &y& Elsevier]

Packham's Triumph pears (Pyrus communis L.) were evaluated from four weeks before harvest for maturity and ethylene production. Firmness and soluble solids showed the highest correlations (r = -0.97 y 0.98, respectively) with days after full bloom (DDPF). Ethylene production was low (< 0.07 mg kg-1) and was not correlated with DDPF. Fruit harvested with 7.8 (E1) and 7.0 kg (E2) were stored in conventional cold air (0°C) and two controlled atmosphere conditions (AC1: 2-2.5% O2/1-1.5% CO2 and AC2: 1-1.3% O2/ 0.5-0.8% CO2), -1°C, for six months. Changes in maturity, and ethylene production were measured (monthly) and incidence of physiological disorders was assessed (after four and six months). Additionally, the ethylene production rate (TPE) was monitored for seven days at room temperature, after each storage period. Fruit from both harvests, stored under AC1 and AC2 were firmer, greener and had lower ethylene production than those of FC. There were no significant differences in ripening between AC1 and AC2. Ethylene accumulation was exponential and occurred earlier and with higher values in FC (900 mg kg-1 maximum at the 5th month), with respect to AC (146 and 230 mg kg-1 for E1 and E2 at the end of the storage period). At room temperature, the TPE of the three storage conditions increased from the second month, but the climacteric peak was observed only in FC. Alter six months, fruit from FC and from both harvests developed superficial scald (17% for E1 and 20% for E2). [ABSTRACT FROM AUTHOR]