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Urbanization is a significant driver of land use change, profoundly impacting biodiversity and ecosystem services worldwide. However, its effects in the tropics, which host some of the planet's highest biodiversity, remain inadequately understood. Orchid bees (Apidae: Euglossini) are key pollinators in Neotropical ecosystems, playing crucial roles in maintaining floral diversity and reproductive success of orchids and other plant families. Yet, little is known about how urbanization influences their diversity and pollination. In this study, we analyzed the diversity and composition or orchid bee communities along an urbanization gradient which extends from the city center to the surrounding cloud forests, which bear high orchid endemism while being highly threatened. Along the same gradient, we further evaluated pollination of a model native orchid, Gongora galeata, which is exclusively pollinated by the bee Euglossa obrima. As expected, increasing urbanization led to a decrease in orchid bee diversity, as well as a clear separation in species composition between urban and non-urban sites and a reduction in G. galeata pollination (i.e. fruit production). However, contrary to our expectations, orchid pollination also decreased with environmental heterogeneity and the abundance of its specific pollinator. Despite urban areas still hosting orchid bee species, our results reveal clear negative effects of urbanization not only on diversity, but also on the ecosystem function of a highly threatened group of bees. This study highlights the importance of considering local factors of urban landscapes for preserving not only biodiversity, but also fundamental ecological processes in cities.

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Animal pollination is crucial for the reproduction and economic viability of a wide range of crops. Despite the existing data, the extent to which citrus crops depend on pollinators to guarantee fruit production still needs to be determined. Here, we described the composition of potential pollinators in citrus (Citrus spp.) from the main growing areas of Argentina; moreover, we combined Bayesian models and empirical simulations to assess the contribution of animal pollination on fruit set and yield ha-1 in different species and cultivars of lemons, grapefruits, mandarins, and oranges. Honeybee (A. mellifera L.) was the most commonly observed potential pollinator, followed by a diverse group of insects, mainly native bees. Regardless of citrus species and cultivars, the probability of flowers setting fruit in pollinated flowers was 2.4 times higher than unpollinated flowers. Furthermore, our simulations showed that about 60% of the citrus yield ha-1 can be attributable to animal pollination across all species and cultivars. Therefore, it is crucial to maintain environments that support pollinator diversity and increase consumer and to producer awareness and demand in order to ensure the significant benefits of animal pollination in citrus production.

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BACKGROUND AND AIMS: The majority of the earth's land area is currently occupied by humans. Measuring how terrestrial plants reproduce in these pervasive environments is essential for understanding their long-term viability and their ability to adapt to changing environments. METHODS: We conducted hierarchical and phylogenetically-independent meta-analyses to assess the overall effects of anthropogenic land-use changes on pollination, and male and female fitness in terrestrial plants. KEY RESULTS: We found negative global effects of land use change (i.e., mainly habitat loss and fragmentation) on pollination and on female and male fitness of terrestrial flowering plants. Negative effects were stronger in plants with self-incompatibility (SI) systems and pollinated by invertebrates, regardless of life form and sexual expression. Pollination and female fitness of pollination generalist and specialist plants were similarly negatively affected by land-use change, whereas male fitness of specialist plants showed no effects. CONCLUSIONS: Our findings indicate that angiosperm populations remaining in fragmented habitats negatively affect pollination, and female and male fitness, which will likely decrease the recruitment, survival, and long-term viability of plant populations remaining in fragmented landscapes. We underline the main current gaps of knowledge for future research agendas and call out not only for a decrease in the current rates of land-use changes across the world but also to embark on active restoration efforts to increase the area and connectivity of remaining natural habitats.

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Most plants produce floral nectar to attract pollinators that impact pollination and seed production; some of them also secrete extrafloral nectar harvested by insects that may influence the plant reproductive success. The aim of this study was to analyze the effects of excluding pollinators and/or ants on the per-plant reproductive success in two species (Dyckia floribunda Griseb. and Dyckia longipetala Baker, Bromeliaceae) that produce floral and extrafloral nectar. The hypothesis states that both ecological processes (pollination and ant defense) involving nectar-mediated animal-plant interactions are beneficial for plant reproductive success. We expected the highest decrease in the plant fruit and seed sets when the pollinators and ants were excluded, and a moderate decrease when solely ants were excluded, compared to the control plants (those exposed to pollinators and ants). In addition, a lower natural reproductive success was also expected in the self-incompatible D. longipetala than in the self-compatible D. floribunda, as the former totally depends on animal pollination for seed production. D. floribunda and D. longipetala presented similar trends in the response variables, and the expected results for the experimental treatments were observed, with some variations between species and among populations. The ecological function of nectar is important because these two plant species depend on pollinators to produce seeds and on ants to defend flowers from the endophytic larvae of Lepidoptera. The study of multispecies interactions through mechanistic experiments could be necessary to clarify the specific effects of different animals on plant reproductive success.

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Gametophytic self-incompatibility (GSI) has been mainly described in species-rich clades within Orchidaceae. We report GSI for a genus within Maxillariinae, one of the most conspicuous and diverse subtribes of neotropical orchids. Here, we describe the reproductive system of Brasiliorchis picta, B. phoenicanthera, and B. porphyrostele. Anatomical studies of fruit development showed that pollen tubes of aborted, self-pollinated flowers degenerate half-way in the stylar channel and never reach the ovules. Spontaneous self-pollination and emasculation set no fruits for none of the sampled species, thus supporting the hypothesis that these three species studied rely on the agency of pollinators and pollinator-mediated cross-pollination to set fruit. Fruit set from cross-pollinations ranged from 33.4 to 77.5%. One self-pollinated fruit of B. porphyrostele developed to completion. All other fruits aborted between 10 and 21 days after pollination. These data support previous evidence of variable strength GSI being exhibited in orchid species. Additional studies of self-incompatibility systems are needed to evaluate their role in species diversification and evolution of reproductive strategies in Maxillariinae and to allow for effective conservation strategies of threatened orchid species.

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Liparisaltomayoënsissp. nov. is described, illustrated, and tentatively assigned to the Neotropical section Decumbentes on the basis of its branching, prostrate rhizomes and upright stems bearing several leaves. Vegetatively, the new species is distinguished by its short, upward stems bearing 3-6 leaves, these with undulate, translucent margins and reticulate, prominent veining on the upper surface. Florally, it is distinctive in the labellum with fleshy basal one-half provided with a central, rounded cavity limited on each side by a prominent, bilobulate ridge and apically by a lunate ridge, and membranaceous, trilobulate apical one-half deflexed ca. 90°. In contrast with other species of section Decumbentes, in which fruit formation is infrequent, in L.altomayoënsis a high proportion (⁓50-100%) of flowers develop into a fruit; in some flowers the pollinaria rotate and contact the stigma, apparently resulting in at least facultative self-pollination. The main differences among the six species of L.sectionDecumbentes hitherto known are contrasted in a dichotomous key. The new species is known only from three populations located in the Bosque de Protección Alto Mayo, on the Amazonian slope of the Andes in northeastern Peru but appears to be under no foreseeable threats.

ResumenLiparisaltomayoënsissp. nov. es descrita, ilustrada y asignada tentativamente a la sección neotropical Decumbentes con base en sus rizomas postrados, ramificados y tallos ascendentes portando varias hojas. Vegetativamente, la nueva especie se distingue por sus tallos ascendentes cortos con 3­6 hojas, éstas con márgenes undulados, translúcidos y venación reticulada prominente en la superficie superior. Floralmente, es distintivo su labelo con la mitad basal carnosa, provista de una cavidad central redondeada que está limitada a cada lado por una cresta bilobulada prominente y apicalmente por una cresta lunada, y la mitad apical del labelo membranácea, trilobulada y deflexa ca. 90°. En contraste con otras especies de la sección Decumbentes, en las que la producción de frutos es infrecuente, en L.altomayoënsis una alta proporción (⁓50­100%) de las flores produce fruto; en algunas flores los polinarios rotan y contactan el estigma, aparentemente resultando en autopolinización al menos facultativa. Las diferencias principales entre las seis especies de L. sección Decumbentes conocidas hasta ahora se contrastan en una clave dicotómica. La nueva especie se conoce solamente de tres poblaciones localizadas en el Bosque de Protección Alto Mayo, en la vertiente amazónica de los Andes en el noreste de Perú, pero no parece estar sujeta a amenazas previsibles.

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S-Nitrosoglutathione plays a central role in nitric oxide (NO) homeostasis, and S-nitrosoglutathione reductase (GSNOR) regulates the cellular levels of S-nitrosoglutathione across kingdoms. Here, we investigated the role of endogenous NO in shaping shoot architecture and controlling fruit set and growth in tomato (Solanum lycopersicum). SlGSNOR silencing promoted shoot side branching and led to reduced fruit size, negatively impacting fruit yield. Greatly intensified in slgsnor knockout plants, these phenotypical changes were virtually unaffected by SlGSNOR overexpression. Silencing or knocking out of SlGSNOR intensified protein tyrosine nitration and S-nitrosation and led to aberrant auxin production and signaling in leaf primordia and fruit-setting ovaries, besides restricting the shoot basipetal polar auxin transport stream. SlGSNOR deficiency triggered extensive transcriptional reprogramming at early fruit development, reducing pericarp cell proliferation due to restrictions on auxin, gibberellin, and cytokinin production and signaling. Abnormal chloroplast development and carbon metabolism were also detected in early-developing NO-overaccumulating fruits, possibly limiting energy supply and building blocks for fruit growth. These findings provide new insights into the mechanisms by which endogenous NO fine-tunes the delicate hormonal network controlling shoot architecture, fruit set, and post-anthesis fruit development, emphasizing the relevance of NO-auxin interaction for plant development and productivity.

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The objective was to study the effectiveness of the growth regulator (ANA + GA3) associated or not to the application of adjuvant and artificial pollination in 'Gefner' atemoya. The experiment was conducted in the experimental orchard at Florida's Tropical Research and Education Center. The experimental design was in a randomized block, with 14 treatments, 10 repetitions and 3 flowers per plot. The highest percentages of fixed fruits were obtained with hand pollination ­ HP and 450 NAA + 1250 GA3 mg L-1 + adjuvant and HP. The use of hand pollination for 'Gefner' atemoya tree proved to be the most efficient method so far. Applying growth regulator without artificial pollination produces parthenocarpic fruits, however with high rate of abortions, and small fruits. Growth regulators together with hand pollination produces small and uneven fruits, and cause reduction in the fruits' titratable acidity. The use of adjuvant caused low fixation and toxicity to fruits, and its use is not recommended.

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Understanding the dormancy phases and dynamics of commercial cultivars in the regions where they are grown allows for the implementation of different cultural practices and aids in the understanding of the temperature requirements for collaboration with genetic improvement programs. The objective of this study was to determine the budding, flowering, and fruit set rates of peach trees cultivated in the municipality of Dois Vizinhos, Southwestern Paraná, Brazil. The present work was developed using the collection of peach trees in the fruit growing sector of the Universidade Tecnológica Federal do Paraná. Sixteen peach cultivars were evaluated: Rubimel, Leonense, Coral, Marli, Charme, Riograndense, Douradão, Chimarrita, Granada, BR1, Bonão, and Eldorado (all planted in 2009), as well as Regalo, Kampai, Fascínio, and Zilli (planted in 2014). The experimental design was completely randomized with four replications of one plant each, in a 16 × 2 bifactorial arrangement (cultivars × year/harvest). Phenology evaluations were performed weekly by counting open (anthesis) and sprouted flower buds, and the fruit set rate was measured just before fruit thinning. Flowering (%), budding (%), and fruit set (%) rates were calculated. It was found that the year/harvest 2016 promoted the highest rates of sprouting and fruit set. The Bonão cultivar showed greater flowering intensity and regularity in the crop years evaluated (2016 and 2017). Coral and Kampai present fruit sets with greater intensities and regularities when compared to the other cultivars evaluated under the climatic condition of the municipality of Dois Vizinhos. The Riograndense cultivar showed greater irregularity in flowering and fruit production.(AU)

Compreender as fases e a dinâmica da dormência de cultivares comerciais na região em que essa está inserida possibilita a execução de diferentes práticas culturais e auxilia na compreensão dos requisitos de frio e calor exigidos pela mesma, colaborando principalmente com os programas de melhoramento genético. O objetivo deste trabalho foi determinar as taxas de brotação, floração e frutificação efetiva de pessegueiros sob as condições ambientais de cultivo no município de Dois Vizinhos, região Sudoeste do Paraná. O presente trabalho foi desenvolvido na coleção de pessegueiros do setor de Fruticultura da Universidade Tecnológica Federal do Paraná. Foram avaliadas 16 cultivares de pessegueiros, sendo 'Rubimel', 'Leonense', 'Coral, 'Marli', 'Charme', 'Riograndense', 'Douradão', 'Chimarrita', 'Granada', 'BR-1', 'Bonão' e 'Eldorado' implantadas em 2009 e 'Regalo', 'Kampai', 'Fascínio' e 'Zilli', implantadas em 2014. O delineamento experimental foi inteiramente casualizado com quatro repetições de uma planta cada, no arranjo bifatorial 16 x 2 (cultivares x anos/safra). As avaliações de fenologia foram realizadas semanalmente através da contagem de gemas florais abertas (antese) e brotadas, e a taxa de frutificação efetiva foi realizada imediatamente antes do raleio de frutos. Foram calculadas as taxas de floração (%), de brotação (%) e de frutificação efetiva (%). Nas condições climáticas do município de Dois Vizinhos, no Estado do Paraná, verificou-se que o ano/safra 2016 promoveu as maiores taxas de brotação e frutificação efetiva. A cultivar 'Bonão' apresentou maior intensidade e regularidade de floração nos anos safra avaliados (2016 e 2017). As cultivares 'Coral' e 'Kampai' apresentam frutificação efetiva com maior intensidades e regularidade em relação aos demais cultivares avaliados para a condição de clima do local avaliado. A cultivar 'Riograndense' apresentou maior irregularidade na floração e na produção de frutos.(AU)

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Abstract Sweet cherry fruit is a tasty and valuable product for consumers. In order to increase the export share of cherry, which is also very important in export, it is beneficial to grow with cherry varieties that mature at different times. The cherries offered to the market in the early period will be more attractive. In this study, morphological and biological features of pistils of early-maturing 'Cristalina', 'Early Lory', 'Prime Giant', fruit set rates and pollen germination status and some chemical applications were investigated. As a result, fruit sets of cultivars were 17.6-28.6% in two years. Significant differences were observed in pistil morphology of the cultivars and 'Cristalina' had shorter pistil (14.35-14.51 mm) and style (11.47-11.65 mm) lengths than the other cultivars. Greater deformation was observed in primary ovules of 'Early Lory' right after anthesis. There were not significant differences in pollen germination ratios of the cultivars, but boric acid treatments improved pollen germination ratios of all cultivars. Boric acid application increased pollen germination with 21%. This was followed by IAA (8%), GA3 (5%), KNO3 (4%). It was concluded based on present findings that in orchard establishment with the early cultivars, flower biology should momentously be assessed.

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Chemical thinning of fruits may be an alternative practice to hand thinning. Hand thinning must be performed in a short time during the fruiting stage, but lack of manpower and the onerous costs of the operation make it increasingly difficult to employ it at the right time and at the ideal intensity. The objective of this study was to examine the effect of different concentrations of metamitron as a chemical thinner on 'PS 10711' peach trees. The experiment was carried out during two harvests in an orchard in the municipality of Eldorado do Sul, in the Central Depression region of the state of Rio Grande do Sul, Brazil. Treatments consisted of the application of metamitron at the concentrations of 100, 200, 300 and 400 mg L-¹; hand thinning; and no thinning. The fruits were thinned chemically and by hand 40 days after the peach trees were in full bloom. Fruit abscission, fruit set, number of fruits, production per tree and fruit quality were evaluated. Metamitron has a thinning effect on the peaches of cultivar PS 10711.The metamitron concentrations of 100 and 200 mg L-¹ result in less fruit abscission as compared with hand thinning. The thinning effect of metamitron alters production per tree, but does not interfere with fruit quality.

O raleio químico de frutos pode ser uma prática alternativa ao raleio manual. O raleio manual necessita ser executado num curto período da frutificação, mas a falta de mão de obra e a onerosidade dos custos da operação cada vez mais dificultam o seu emprego no momento adequado e na intensidade ideal. O objetivo desse trabalho foi avaliar o efeito de diferentes concentrações do metamitron como raleante químico nos pessegueiros ‘PS 10711’. O experimento foi realizado durante duas safras num pomar do município de Eldorado do Sul, região da Depressão Central do Rio Grande do Sul, Brasil. Os tratamentos consistiram na aplicação de metamitron nas concentrações de 100 mg L-¹, 200 mg L-¹, 300 mg L-¹ e 400mg L-¹, raleio manual e plantas sem raleio. O raleio químico e manual dos frutos foram realizados aos 40 dias após a plena floração dos pessegueiros. Avaliou-se a abscisão de frutos, frutificação efetiva, número de frutos, produção por planta e a qualidade dos frutos. O metamitron possui efeito raleante em pêssegos da cultivar PS 10711. As concentrações de 100 e 200 mg L-¹ de metamitron promove abscisão de frutos inferior ao raleio manual. O efeito raleante do metamitron altera a produção por planta, mas não interfere na qualidade dos frutos.

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Chemical thinning of fruits may be an alternative practice to hand thinning. Hand thinning must be performed in a short time during the fruiting stage, but lack of manpower and the onerous costs of the operation make it increasingly difficult to employ it at the right time and at the ideal intensity. The objective of this study was to examine the effect of different concentrations of metamitron as a chemical thinner on 'PS 10711' peach trees. The experiment was carried out during two harvests in an orchard in the municipality of Eldorado do Sul, in the Central Depression region of the state of Rio Grande do Sul, Brazil. Treatments consisted of the application of metamitron at the concentrations of 100, 200, 300 and 400 mg L-¹; hand thinning; and no thinning. The fruits were thinned chemically and by hand 40 days after the peach trees were in full bloom. Fruit abscission, fruit set, number of fruits, production per tree and fruit quality were evaluated. Metamitron has a thinning effect on the peaches of cultivar PS 10711.The metamitron concentrations of 100 and 200 mg L-¹ result in less fruit abscission as compared with hand thinning. The thinning effect of metamitron alters production per tree, but does not interfere with fruit quality.(AU)

O raleio químico de frutos pode ser uma prática alternativa ao raleio manual. O raleio manual necessita ser executado num curto período da frutificação, mas a falta de mão de obra e a onerosidade dos custos da operação cada vez mais dificultam o seu emprego no momento adequado e na intensidade ideal. O objetivo desse trabalho foi avaliar o efeito de diferentes concentrações do metamitron como raleante químico nos pessegueiros ‘PS 10711. O experimento foi realizado durante duas safras num pomar do município de Eldorado do Sul, região da Depressão Central do Rio Grande do Sul, Brasil. Os tratamentos consistiram na aplicação de metamitron nas concentrações de 100 mg L-¹, 200 mg L-¹, 300 mg L-¹ e 400mg L-¹, raleio manual e plantas sem raleio. O raleio químico e manual dos frutos foram realizados aos 40 dias após a plena floração dos pessegueiros. Avaliou-se a abscisão de frutos, frutificação efetiva, número de frutos, produção por planta e a qualidade dos frutos. O metamitron possui efeito raleante em pêssegos da cultivar PS 10711. As concentrações de 100 e 200 mg L-¹ de metamitron promove abscisão de frutos inferior ao raleio manual. O efeito raleante do metamitron altera a produção por planta, mas não interfere na qualidade dos frutos.(AU)

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Network analysis is a powerful tool to understand community-level plant-pollinator interactions. We evaluated the role of floral visitors on plant fitness through a series of pollination exclusion experiments to test the effectiveness of pollinators of an Ipomoea community in the Pacific coast of Mexico, including: (1) all flower visitors, (2) visitors that contact the reproductive organs, (3) visitors that deposit pollen on stigmas, and (4) visitors that mediate fruit and seed production. Our results show that networks built from effective pollination interactions are smaller, less connected, more specialized and modular than floral visitor networks. Modules are associated with pollinator functional groups and they provide strong support for pollination syndromes only when non-effective interactions are excluded. In contrast to other studies, the analyzed networks are not nested. Our results also show that only 59% of floral visitors were legitimate pollinators that contribute to seed production. Furthermore, only 27% of the links in visitation network resulted in seed production. Our study shows that plant-pollination networks that consider effectiveness measures of pollination in addition to floral visitation provide insightful information about the different role floral visitors play in a community, encompassing a large number of commensalistic/antagonistic interactions and the more restricted set of mutualistic relationships that underlie the evolution of convergent floral phenotypes in plants.

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Yield-related traits of Capsicum chinense are highly dependent on coordination between vegetative and reproductive growth, since the formation of reproductive tissues occurs iteratively in new sympodial bifurcations. In this study, we used two C. chinense cultivars (Biquinho and Habanero), contrasting for fruit size and fruit set, to investigate the responses of nitrogen (N) deficiency and excess on growth, photosynthesis, carbon (C) and N metabolisms as well as yield-related traits. Both cultivars increased biomass allocation to leaves in conditions of higher N supply and exhibited a parabolic behavior for fruit biomass allocation. Plants growing under N-deficiency produced a lower number of flowers and heavier fruits. Contrarily, plants under high N condition tended to decrease their CO2 assimilation rate, harvest index and fruit weight. Biquinho, the cultivar with lower fruit size and higher fruit set, was initially less affected by excess of N due to its continuous formation of new reproductive sinks in relation to Habanero (which has lower fruit set and higher fruit size). The results suggest that N amount influences sucrose supply to different organs and can differentially affect yield-related traits between Capsicum cultivars with contrasting source-sink relations.

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The present research aimed to evaluate the effect of applying gibberellic acid (GA3) with hand (HP) or natural pollination (NP) on fruit set and the fruit quality of ‘Red and ‘Lessard Thai sugar apple and ‘Gefner atemoya fruits.This study was performed in an experimental orchard located in Homestead, Florida, USA. The experimental design included randomized blocks, with eight treatments, four replicates and four plants per plot. Treatments included: (1) HP; (2) HP + 10 mg L-1 GA3; (3) HP + 100 mg L-1 GA3; (4) HP + 1,000 mg L-1 GA3; (5) NP; (6) NP + 10 mg L-1 GA3; (7) NP + 100 mg L-1 GA3 and (8) NP + 1,000 mg L-1 GA3. The HP plus 1,000 mg L-1 GA3 promoted fruit setting above 90% over the 14 weeks for all genotypes evaluated. Significant increments for length and total fruit weight were observed. ‘Red sugar apple and atemoya had a reduced number of seeds per fruit. The NP plus GA3 (1,000 mg L-1) was effective in producing high quality seedless ‘Gefner atemoya fruits. This investigation demonstrated that GA3 plus hand pollination produced high quality sugar apple and atemoya seeded fruits and in association with natural pollination promoted seedless ‘Gefneratemoya fruits.(AU)

O presente trabalho teve como objetivo avaliar o efeito da aplicação de ácido giberélico (GA3) associado com e sem polinização artificial, no pegamento e na qualidade de frutos das pinheiras ‘Red e ‘Lessard Thai e da atemoieira‘Gefner. O experimento foi realizado em pomar localizado em Homestead, EUA. O delineamento experimental foi em blocos casualizados, com oito tratamentos, quatro repetições e quatro plantas por parcela. Os tratamentos utilizados neste experimento foram: 1) Polinização Artificial (PA); 2) PA + 10 mg L-1 GA3; 3) PA + 100 mg L-1 GA3; 4) PA + 1000 mg L-1 GA3; 5) Polinização natural (PN); 6) PN + 10 mg L-1 GA3; 7) PN + 100 mg L-1 GA3; e 8) PN + 1000 mg L-1 GA3. A PA combinada com a concentração de 1000 mg L-1 de GA3 promoveu o estabelecimento de frutos acima de 90% durante as 14 semanas de avaliação para todos os genótipos avaliados. Incrementos significativos para o comprimento e peso dos frutos também foram observados a variedade de pinha “Red” e a atemoia, em que apresentaram redução no número total de sementes.A PN em associação com GA3 (1000 mg L-1) foi eficaz na produção de frutos sem sementes de alta qualidade em atemóia ‘Gefner. Estes dados mostram que o GA3, combinado com a polinização manual, produziu frutos com semente de alta qualidade e, em associação com a polinização natural, promoveu frutos sem sementes em atemóia ‘Gefner.(AU)

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ABSTRACT: The present research aimed to evaluate the effect of applying gibberellic acid (GA3) with hand (HP) or natural pollination (NP) on fruit set and the fruit quality of 'Red' and 'Lessard Thai' sugar apple and 'Gefner' atemoya fruits.This study was performed in an experimental orchard located in Homestead, Florida, USA. The experimental design included randomized blocks, with eight treatments, four replicates and four plants per plot. Treatments included: (1) HP; (2) HP + 10 mg L-1 GA3; (3) HP + 100 mg L-1 GA3; (4) HP + 1,000 mg L-1 GA3; (5) NP; (6) NP + 10 mg L-1 GA3; (7) NP + 100 mg L-1 GA3 and (8) NP + 1,000 mg L-1 GA3. The HP plus 1,000 mg L-1 GA3 promoted fruit setting above 90% over the 14 weeks for all genotypes evaluated. Significant increments for length and total fruit weight were observed. 'Red' sugar apple and atemoya had a reduced number of seeds per fruit. The NP plus GA3 (1,000 mg L-1) was effective in producing high quality seedless 'Gefner' atemoya fruits. This investigationdemonstratedthat GA3 plus hand pollination produced high quality sugar apple and atemoya seeded fruits and in association with natural pollination promoted seedless 'Gefner'atemoya fruits.

RESUMO: O presente trabalho teve como objetivo avaliar o efeito da aplicação de ácido giberélico (GA3) associado com e sem polinização artificial, no pegamento e na qualidade de frutos das pinheiras 'Red' e 'Lessard Thai' e da atemoieira'Gefner'. O experimento foi realizado em pomar localizado em Homestead, EUA. O delineamento experimental foi em blocos casualizados, com oito tratamentos, quatro repetições e quatro plantas por parcela. Os tratamentos utilizados neste experimento foram: 1) Polinização Artificial (PA); 2) PA + 10 mg L-1 GA3; 3) PA + 100 mg L-1 GA3; 4) PA + 1000 mg L-1 GA3; 5) Polinização natural (PN); 6) PN + 10 mg L-1 GA3; 7) PN + 100 mg L-1 GA3; e 8) PN + 1000 mg L-1 GA3. A PA combinada com a concentração de 1000 mg L-1 de GA3 promoveu o estabelecimento de frutos acima de 90% durante as 14 semanas de avaliação para todos os genótipos avaliados. Incrementos significativos para o comprimento e peso dos frutos também foram observados a variedade de pinha "Red" e a atemoia, em que apresentaram redução no número total de sementes.A PN em associação com GA3 (1000 mg L-1) foi eficaz na produção de frutos sem sementes de alta qualidade em atemóia 'Gefner. Estes dados mostram que o GA3, combinado com a polinização manual, produziu frutos com semente de alta qualidade e, em associação com a polinização natural, promoveu frutos sem sementes em atemóia 'Gefner'.

RESUMEN

Among the main problems of some temperate fruit species, such as the apple tree (Malus domestica), are the poor set of fruits and low production. Polyamines and Self-Incompatibility Control Substances (SICS), involving mineral nutrients such as manganese and boron, are the major chemical compounds used to reduce these problems. The aim of this study was to use popular polyamines putrescine (Put) at 0.1, 0.25 mM, spermine (Spm) and spermidine (Spd) both at 0.05, 0.25 mM and SICS at 1, 2 mg L-1, alone or with cotton coverage bags and control to show the effects of these chemical compounds on yield indices and qualitative traits of apple (Malus domestica) cv ‘Red Delicious’. Results showed that Spd (0.25 mM) and SICS (1 mg L-1) had higher effect on yield per weight and per fruit number, final fruit set and ISI, but Spd (0.25 mM) decreased final drop. Put (0.1 mM + ccb), Spd (0.25 mM) and SICS (2 mg L-1 + ccb) were the most suitable treatments in order to increase the qualitative characteristics.

Entre os principais problemas de algumas espécies frutíferas de clima temperado, como a macieira (Malus domestica), está o fraco conjunto de frutos e a baixa produção. As Poliaminas e Substancias de Controle de Auto-Incompatibilidade (self-incompatibility control substances-SICS) (envolvendo nutrientes minerais tais como manganês e boro) são os principais compostos químicos usados para reduzir esses problemas. O objetivo deste trabalho foi empregar a poliamina putrescina (Put) em 0,1, 0,25 mM, espermina (Spm) e espermidina (Spd) ambas em 0,05, 0,25 mM e SICS em 1,2 mg L-1, sozinhos ou com sacos cobertos de algodão, para demonstrar o efeito destes elementos químicos nos índices de produção e características qualitativas da maça (Malus domestica) ‘Red Delicious’. Resultados mostraram que a espermidina (0.25 mM) e SICS (1 mg L-1) tiveram um efeito maior na produção por peso e pelo número de frutos, o conjunto final de frutos e ISI, mas a espermidina (0.25 mM) caiu na produção final. Put (0.1 mM + sca), Spd (0.25 mM) e SICS (2 mg L-1 + sca) foram os tratamentos mais adequados para aumentar as características qualitativas.

RESUMEN

As diversas tentativas falhas de produção de peras no Brasil são impulsionadas pelo elevado consumo, que apresenta um cenário crescente de importação para atender a demanda interna. Em 2015, foram importadas 179 mil toneladas de peras, sendo a maior parte da Argentina e Portugal. A limitação do cultivo de pereira não tem sido por falta de mercado, mas devido a diversos fatores, como por exemplo, a baixa frutificação efetiva, a insuficiente formação de estruturas de produção e o excesso de crescimento vegetativo. O objetivo deste trabalho foi avaliar o crescimento vegetativo e frutificação efetiva de pereiras europeias submetidas a diferentes técnicas de redução de vigor. O experimento foi instalado na safra 2012/13 em um pomar comercial de pereiras localizado no município de Vacaria RS, situada a 971 m de altitude. As pereiras Packhams Triumph, Williams, Red Bartlett, Abate Fetel e Carrick, todas enxertadas sobre o portaenxerto Pyrus calleryana, foram submetidas aos tratamentos de anelamento simples, anelamento duplo, corte de tronco simples, corte de tronco duplo e aplicação do fitorregulador Trinexapac-etil (1600 ppm). De acordo com os resultados obtidos foi possível observar que houve redução do crescimento vegetativo apenas na cultivar Packhams submetida ao anelamento duplo, corte de tronco simples e Trinexapac-etil. A utilização da técnica de anelamento e corte de tronco incrementa o retorno de floração e também a produtividade das pereiras ‘Abate Fetel’ e ‘Carrick’, bem como a aplicação de Trinexapac-etil reduz o retorno de florescimento destas cultivares nas condições do estudo.

The various failed attempts to produce pears in Brazil are driven by high consumption, which presents a growing scenario of imports to attend to the consumers demand. In 2015, 179 thousand tons of pears were imported, most from Argentina and Portugal. The limitation of pear cultivation has not been due to lack of market, but due to several factors, such as low fruit set, insufficient formation of production structures and excessive vegetative growth. The objective of this work was to evaluate the vegetative growth and fruit set of European pear trees submitted to different growth control techniques. The experiment was conducted during 2012/2013 and 2013/2014 season in a commercial pear orchard located in Vacaria city, Rio Grande do Sul State, at 971 m altitude. Packham’s Triumph, William’s, Red Bartlett, Abate Fetel and Carrick, all grafted on Pyrus calleryana, were submitted to treatments of simple girdling, double girdling, single trunk cutting, double trunk cutting and application of the Trinexapac-ethyl plant growth regulator (1600 mg L-1). According to the results, it was possible to observe that there was a reduction of vegetative growth only in the Packham’s cultivar submitted to double girdling, single trunk cutting and Trinexapac-ethyl. The use of the trunk cutting and girdling technique increases the flowering return and also the productivity of ‘Abate Fetel’ and ‘Carrick’ pear trees, and the Trinexapac-ethyl decreases the return bloom of ‘Abate Fetel’ and ‘Carrick’ pear trees in the studied conditions.

Asunto(s)

RESUMEN

As diversas tentativas falhas de produção de peras no Brasil são impulsionadas pelo elevado consumo, que apresenta um cenário crescente de importação para atender a demanda interna. Em 2015, foram importadas 179 mil toneladas de peras, sendo a maior parte da Argentina e Portugal. A limitação do cultivo de pereira não tem sido por falta de mercado, mas devido a diversos fatores, como por exemplo, a baixa frutificação efetiva, a insuficiente formação de estruturas de produção e o excesso de crescimento vegetativo. O objetivo deste trabalho foi avaliar o crescimento vegetativo e frutificação efetiva de pereiras europeias submetidas a diferentes técnicas de redução de vigor. O experimento foi instalado na safra 2012/13 em um pomar comercial de pereiras localizado no município de Vacaria RS, situada a 971 m de altitude. As pereiras Packhams Triumph, Williams, Red Bartlett, Abate Fetel e Carrick, todas enxertadas sobre o portaenxerto Pyrus calleryana, foram submetidas aos tratamentos de anelamento simples, anelamento duplo, corte de tronco simples, corte de tronco duplo e aplicação do fitorregulador Trinexapac-etil (1600 ppm). De acordo com os resultados obtidos foi possível observar que houve redução do crescimento vegetativo apenas na cultivar Packhams submetida ao anelamento duplo, corte de tronco simples e Trinexapac-etil. A utilização da técnica de anelamento e corte de tronco incrementa o retorno de floração e também a produtividade das pereiras ‘Abate Fetel e ‘Carrick, bem como a aplicação de Trinexapac-etil reduz o retorno de florescimento destas cultivares nas condições do estudo.(AU)

The various failed attempts to produce pears in Brazil are driven by high consumption, which presents a growing scenario of imports to attend to the consumers demand. In 2015, 179 thousand tons of pears were imported, most from Argentina and Portugal. The limitation of pear cultivation has not been due to lack of market, but due to several factors, such as low fruit set, insufficient formation of production structures and excessive vegetative growth. The objective of this work was to evaluate the vegetative growth and fruit set of European pear trees submitted to different growth control techniques. The experiment was conducted during 2012/2013 and 2013/2014 season in a commercial pear orchard located in Vacaria city, Rio Grande do Sul State, at 971 m altitude. Packhams Triumph, Williams, Red Bartlett, Abate Fetel and Carrick, all grafted on Pyrus calleryana, were submitted to treatments of simple girdling, double girdling, single trunk cutting, double trunk cutting and application of the Trinexapac-ethyl plant growth regulator (1600 mg L-1). According to the results, it was possible to observe that there was a reduction of vegetative growth only in the Packhams cultivar submitted to double girdling, single trunk cutting and Trinexapac-ethyl. The use of the trunk cutting and girdling technique increases the flowering return and also the productivity of ‘Abate Fetel and ‘Carrick pear trees, and the Trinexapac-ethyl decreases the return bloom of ‘Abate Fetel and ‘Carrick pear trees in the studied conditions.(AU)

Asunto(s)