Idemir Citadin

Chilling privation during dormancy period and carbohydrate mobilization in Japanese pear trees

The flower bud abortion is one of the main problems that limit commercial pear (Pyrus pyrifolia) production in the southern region of Brazil. Insufficient chilling during the dormancy period is known as the main factor of this problem. One of the hypotheses to explain this problem is that the starch mobilization and carbohydrate fluxes to the buds are impeded when mild temperatures occurred during winter. This study compared the total soluble sugars (TSS) and reducing sugars (RS) concentrations, the cell wall acid invertase (CWAI - EC 3.2.1.26) and sucrose-phosphate synthase (SPS - EC 2.4.1.14) activities in wood of branches and floral buds of Japanese pear trees cv. Housui, grafted on Pyrus calleryana and submitted to chilling conditions during the dormancy period. Treatments were: (i) natural conditions; (ii) continuous artificial chilling; (iii) alternating temperatures, and (iv) total chilling privation. TSS and RS contents, as well as CWAI and SPS activities in tissues of branches that received insufficient chilling were lower than those that received sufficient chilling during winter. The starch concentration was superior in wood tissues of branches kept under chilling privation. The chilling privation disturbs carbohydrate mobilization in pear trees, reducing the sucrose synthesis capacity in wood tissues (source) and sucrose importation by the floral buds (sink).

Repetibilidade de caracteres de fruto em araçazeiro e pitangueira

The aim of this research was to estimate the repeatability traits of strawberry guava and surinam cherry fruits. It was evaluated in four productive cycles, the traits weight, diameter, total soluble solids and fruit production in ten selection of strawberry guava and weight, diameter and total soluble solids in nine selection of surinam cherry from the Germplasm Bank of the Embrapa Clima Temperado, in Pelotas-RS, Brazil. The repeatability coefficient, minimum observations number and determination coefficient were estimated by analysis of variance, principal components analysis and structural analysis. The repeatability coefficient was better estimated by the method of principal components analysis, based on covariance matrix. The fruit weight is adequate to phenotypic selection in strawberry guava and surinam cherry. Its only required a measurement to obtain the value of fruit weight value of strawberry guava selections, with 90% accuracy. With four years of evaluation, its possible to infer the actual value with reliability above 80% for all characters. This facilitates phenotypic selection for these traits in strawberry guava and surinam cherry breeding programs.

Zoneamento agroclimático para o pessegueiro e a nectarineira no Estado do Paraná

ABSTRACT - Peach and nectarine crops, despite their high climatic and market potential, are not yet well exploited in the state ofParana. The objective of this research was to indicate zones with lower climatic risk for production of these crops in the state ofParana, Brazil, using climatic risk analysis and agronomic data. Historical data of 32 weather stations of IAPAR were analyzed toestimate and map the risks of late frost and the average totals of chilling hours above 7.2 o C accumulated from May to September. Theregions in which the last frost occurs before flowering and with the total chilling hours suitable to the cultivars needs were consideredapt. Most of the north, west and the coast of Parana do not have enough chilling hours. The areas located in the south with alt itudesabove 800 m are the most suitable. Within the apt areas eight zones were classified according to the chilling requirements of p eachesand nectarine varieties and climatic conditions of each region: zone 1 (75 to 150 hf); zone 2 (150 to 200 hf); zone 3 (200 to 250 hf); zone4 (250 to 300 hf); zone 5 (300 to 350 hf); zone 6 (350 to 400 hf), zone 7 (400 to 450 hf) and zone 8 (> 450 hf). The zones with lower altitudeand higher temperatures accumulate less chilling hours from May to September and are indicated for cultivars with lower chillingrequirement. The zones with higher altitudes and high chilling accumulation are suitable for varieties with high chilling requi rements(> 400 chilling hours). The last frost is likely to occur in the last ten days of August in the colder regions and do not caus e damagesto suitable varieties of peaches and nectarine. The results obtained in this work support the adoption of policies to foment thesecrops in the state of Parana with low risk.

Propagação de Jabuticabeira por enxertia e alporquia

ABSTRACT – The objective of this work was to test the efficiency of grafting and air layering propagation techniques for Jabuticaba tree. Compatibility of grafting of three species of jabuticaba tree (Plinia cauliflora, P. trunciflora and P. jaboticaba) on rootstocks of P. cauliflora, and two periods (May and August) was tested.The percentage of grafting, number and size of shoots, was evaluated 90 days after the experiment started. Air layering was made in P. cauliflora using two diameters of branches (1.0-1.5 cm and 2.0-2.5 cm) and two widths of girdling (1.5 cm and 3.0 cm). It was evaluated the rooting percentage, the number and the length of roots, 180 days after the experiment started. Both, grafting and air layering are recommended for Jabuticaba tree propagation, because these techniques provide high percentage of nursery plant formation, up to 72.9% and 87.5%, respectively. There was grafting development of the three species grafted onto P. cauliflora rootstocks. The utilization of grafts collected from plants in fructification should be avoided, because they reduce the percentage of grafting development. In air layering, branches with diameter of 2.0-2.5 cm provide higher percentage of rooting, number and size of roots, than branches with smaller diameter (1.0 to 1.5 cm). Index terms: Plinia sp., plant propagation, compatibility, rooting.

Avaliação da necessidade de frio em pessegueiro

ABSTRACT - Chilling requirement was investigated in six peach [ Prunus persica (L.) Batsch] cultivars observing plants in containers, with one ortwo years, artificially chilled by 150, 300, 450, and 600 hours at 2oC, and in excised shoots that were periodically taken from the orchard during the restperiod. Chilling requirement of ‘Precocinho’ is 300 hours at 2oC (around 150 chilling units - CU - using Utah Model) or around 200 hours under 12oC;‘Riograndense’ and ‘Eldorado’ have 450 chilling hours at 2oC (225 CU) or 365 chilling hours under 12oC; ‘BR-1’ is 450 chilling requirement at 2oC (225CU) or 418 chilling hours under 12 oC; and ‘Planalto’ and ‘Della Nona’ are over 600 chilling hours at 2oC (>300 CU). It was not possible to estimatechilling requirement in ‘Della Nona’ using temperatures under 12 oC. Index terms: Prunus persica , endodormancy, adaptation. INTRODUCAO O desenvolvimento de plantas perenes de folhas caducas eafetado por fatores endogenos e exogenos. Quando as condicoesexogenas sao desfavoraveis, a planta reage, paralisando o crescimento.O mecanismo de controle da paralisacao e retomada de crescimento,apesar de pouco esclarecido, esta relacionado com a genetica e fisiolo-gia das plantas. A temperatura e, sem duvida, o principal fator exogenodesencadeador deste processo. Mauget (1987) cita que o principal efei-to da temperatura se refere a acao positiva das baixas temperaturas deinverno sobre a superacao da endodormencia.Quando as especies de clima temperado sao introduzidas emregioes tropicais ou subtropicais, manifestam diversos disturbios fisio-logicos, como: abertura de gemas de forma escalonada no tempo, redu-cao no numero de gemas brotadas, formacao de rosetas foliares, redu-cao na producao e longevidade e, em casos extremos, a propria sobrevi-vencia da planta e ameacada (Diaz et al., 1987; Herter, 1992). As flutuacoesde temperatura durante o inverno podem afetar negativamente a supera-cao da endodormencia nestas especies. Erez e Lavee (1971) e Erez et al.(1979) relatam o efeito adverso das altas temperaturas ciclicas sobre aendodormencia, podendo temperaturas elevadas, apos um periodo defrio, causar um atraso na brotacao.Um metodo tradicional de prever a necessidade de frio dasespecies e/ou cultivares consiste em submeter ramos inteiros, retiradosde arvores em diferentes epocas, a uma temperatura favoravel ao cresci-mento, computando o percentual de abertura de gemas apos 21 dias ouo numero de dias necessarios ao desenvolvimento de uma certa percen-tagem fixa, porem arbitraria, de gemas. Quanto maior for o porcentual deabertura aos 21 dias ou quanto menor o numero de dias para atingir oporcentual fixo, mais proximo da superacao da endodormencia encon-tra-se a cultivar ou especie estudada. Esta tecnica, ha muito tempo, vemsendo estudada para fixar as datas de fim de dormencia (Weinberger,1950; Erez e Lavee, 1971; Richardson et al., 1974; Kobayashi et al., 1982),porem o principal problema e nao considerar, ou nao permitir isolar, osefeitos das inibicoes correlativas entre as gemas vegetativas e a neces-sidade de calor necessaria para a antese.Outro metodo utilizado e o “teste das estacas de nos isolados”(Balandier, 1992; Herter, 1992). Fragmentos de ramos, contendo apenasum no com gemas, eliminando, assim, grande parte das inibicoescorrelativas, sao submetidos a temperatura e fotoperiodo adequados aocrescimento. O tempo necessario para abertura de uma gema, sob estascondicoes, mede a intensidade da dormencia. Os principais defeitosdeste metodo foram assinalados por Champagnat (1983), Mauget (1987)e Balandier (1992).Outro fator a ser considerado na quantificacao da dormencia ea necessidade de calor, verificado principalmente em gemas florais.Citadin et al. (2001) observaram diferencas entre gemas vegetativas eflorais de pessegueiro quanto a necessidade de calor e tambem entrecultivares. Neste sentido, e importante estabelecer uma metodologiaclara de determinacao da necessidade de frio durante a endodormencia,considerando as possiveis interacoes com a necessidade de calor.O objetivo deste trabalho foi determinar a necessidade de friode seis cultivares de pessegueiro, atraves de duas diferentes tecnicas.

Cutting propagation of Jabuticaba tree.

ABSTRACT – The objective of this work was to test the efficiency of cutting technique for the propagation of Jabuticaba tree (Plinia cauliflora). The rooting potential of wood cutting was tested, using four concentrations of Indolbutiric Acid - IBA (0, 2000 , 4000 and 6000 mg L -1 ) and two procedures (cross section and cutting girdling). Also the rooting potential of softwood terminal cuttings was tested, using five concentrations of IBA (0, 2000, 4000, 6000 and 8000 mg L -1 ) in two periods of implantation (October and December 2007). The rooting percentage was evaluated 180 days after the experiment started. It was observed that rooting of wood cutting is dependent on the application of IBA, so the biggest rooting percentage (50%) was obtained in the biggest concentration of IBA (6000 mg L -1 ) associated with cross section. For the softwood terminal cuttings, the rooting percentage was smaller (maximum of 10%), however there is the potential of rooting, so adjustments in the technique must be tested for maximization.Index terms: Plinia sp., plant propagation, rooting, IBA.

Indução de fitoalexinas em cotilédones de soja em resposta a derivados de folhas de pitangueira

The worldwide demand for food without pesticides has stimulated the research on alternative methods to control pathogens in plants. The activation of defense mechanisms by inductors seems a viable and promising alternative. The use of medicinal plants extracts has demonstrated capacity to induce the production of phytoalexins, as a mechanism of defense in treated plants. The objective of this research was to verify the potential of Eugenia uniflora L. (surinan cherry) to induce phytoalexins in cotyledons of soybean (Glycine max). The derivatives alcoholic extract, infusion, maceration and decoction, obtained of surinan cherry were used in the concentrations of 0.1; 1; 10 and 40%, beyond essential oil. Water was used for the control and chitosan (1%) as inductor reference. The preparations of surinan cherry presented capacity of induction of the phytoalexins glyceolin in cotyledons of soybean, with the increasing concentration of the preparations. The essential oil presents detachable effect in the induction of phytoalexins in relation to the other preparations. Chitosan induces phytoalexins in cotyledons soybean and can be used in similar studies as a reference inductor.

Armazenamento a vácuo prolonga a viabilidade de sementes de jabuticabeira

O objetivo deste trabalho foi avaliar a viabilidade de sementes de jabuticabeira (Plinia cauliflora) sob diferentes condicoes de armazenamento. Para isso, foram realizados dois experimentos. No primeiro, testou-se a viabilidade de sementes armazenadas sob tres diferentes temperaturas (temperatura ambiente, 12°C e 6°C) e periodos de armazenamento (5; 10; 20; 40 e 80 dias apos a extracao das sementes). No segundo experimento, testou-se a viabilidade de sementes armazenadas a vacuo sob tres condicoes (com agua esterilizada, com tampao fosfato pH 7,0 e a seco) e periodos de armazenamento (5; 20; 35; 50 e 65 dias apos a extracao das sementes). Sob atmosfera normal, as sementes de jabuticabeira conservam viabilidade por apenas cinco dias, com maior emergencia sob temperatura ambiente (83,35%). As sementes de jabuticabeira perdem totalmente a viabilidade com teor de umidade proximo a 10%. As sementes de jabuticabeira armazenadas a vacuo com tampao fosfato mantem razoavel viabilidade (41,6%) ate 65 dias de armazenamento.

Variability in leaf rust susceptibility among peach cultivars

The aim of this work was to estimate the susceptibility of thirty-six peach cultivars to leaf rust caused by Tranzschelia discolor f. sp. persica. The incidence and severity of the disease as well as defoliation in peach trees of an experimental orchard of Parana Federal University of Technology, Campus Dois Vizinhos were evaluated on the growing seasons 2004/2005 and 2005/2006. Immunity to this disease was not observed in the studied cultivars. There was difference in leaf rust intensity depending on the growing season conditions. Cultivars ‘Pilcha‘, ‘Sinuelo‘, ‘Chirua‘, ‘Sulina‘, ‘Eldorado‘ and ‘Pampeano‘ showed tolerance to leaf rust, whereas cultivars ‘Vila Nova‘, ‘Fla 1372‘, ‘Coral 2‘, ‘Chimarrita‘, ‘Della Nona‘, ‘BR-1‘ and ‘Guaiaca‘ showed high susceptibility.

Phenology of blooming and fruiting of Myrtaceae native species of Araucaria Forest.

ABSTRACT – Studies of phenology are important for the development of various cultural treatments of fruit species. Therefore, it was studied the phenology of blooming and fruiting of Myrtaceae native species of Araucaria Forest, in the Southwest of the state of Parana, Brazil. Observations about phenology of Eugenia unifl ora , Eugenia involucrata , Eugenia pyriformis , Campomanesia xantocarpa , and Psidium cattleyanum were conducted from July 2007 to February 2008, in three plants of each species. There to manufacture the curves of the fruits growth based in mass of dry matter, in two weekly ratings. The fl owering of species oc-curred between late August and early November. The Eugenia involucrata is the earliest (cycle of 43 days), with ripening between mid and end of October, while the Psidium cattleyanum presents a reproductive cycle longer (98 days), with maturity during the month of February. There are differences in behavior accumula-tion of mass of dry matter between genotypes of the same species.