Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Ann Bot ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38722218

RESUMO

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.

2.
Heliyon ; 9(11): e22125, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38034761

RESUMO

Background: Rootstocks less vigorous are among the most crucial management techniques to modernize fruit cultivation. Replanting with fallow land has become necessary due to a lack of land to establish new orchards. Objective: The aim of this study is to determine the effect of various rootstocks of the American Geneva® series on the yield performance of the apple (Malus domestica Borkh) cultivars 'Gala Select' and 'Fuji Suprema' under replanting conditions in southern Brazil. Methods: After two years of fallow land, the experiments were initiated in 2017 and conducted during the 2018, 2019, 2020, and 2021 growing seasons in Painel and Caxias do Sul municipalities at the Santa Catarina and the Rio Grande do Sul State, respectively. The 'Gala Select' and 'Fuji Suprema' were grafted onto the G.202, G.814, G.210, and G.213 Geneva series rootstocks in a tall spindle training system using a randomized complete block design with four replicates. Principal component analysis (PCA) was used to assess the interrelationship among the variable's vigor, productivity, and fruit quality. Results: The PCA result showed significant differences in vigor, productivity, and fruit quality when the G.210 and G.213 and G.814 and G.213 Geneva series rootstocks were used in combination with Gala Select and Fuji Suprema cultivars, respectively. The PCA analysis clustered all cultivar/rootstock combinations into two groups, based on their vigor and productivity and the yield performance and fruit quality data, that differed significantly among combinations and regions. The 'Gala Select'/G.202 and 'Fuji Suprema'/G.213 combinations were less vigorous than the 'Gala Select'/G.210 and 'Fuji Suprema'/G.814 combinations. However, 'Gala Select'/G.210 (semi-dwarfing) and G.213 (dwarfing) are the combinations with high yield performance, productive efficiency and fruit quality, being more reliable to the producer, and less vigorous, resulting in lower labor costs under replating conditions, with two years of fallow land, from 2018 until 2021 growing seasons.

3.
Colloq. Agrar ; 18(3): 11-23, maio-jun. 2022. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1410431

RESUMO

Studies on the nutritional status of habanero pepper (Capsicum chinense Jacq.) in relation to organic fertilization are still incomplete and preliminary. The aim of study were to evaluer the effect of rates of organic fertilizer produced from Family agriculture waste on growth and nutritional status habanero pepper. The experiment was carried out in a greenhouse located at the Federal Rural University of Amazonia, municipality of Belém, State for Pará, Brazil. A completely randomized design (CRD) was used, with five treatments and four replications. Each experimental plot consisted of a pot with a volume of 3.6 dm3of soil, in which the seeds were sown. Five doses of organic fertilizer were tested : 0%, 15% (525 g), 30% (1050 g), 45% (1575 g) and 60% (2100 g) of substrate volume, composed of a mixture of chicken manure (10%), duck manure (20%), cassava peel (15%) , cassava leaf (15%), bean straw (15%), rice husk (15%) and corn cob (10%), mixed in volumetric proportions in the substrate. To mix the different amounts of organic fertilizer, a Yellow Latosol with a sandy texture was used, removed from the surface layer (0-20 cm). The best results were achieved at 103 days using a dose of 60% of organic fertilizer. The content and accumulation of macronutrients in leaf tissues showed the following order: N˃K≥S˃Ca≥Mg˃P and N˃K˃S˃Mg˃Ca˃P. In the fruits, the content and accumulation of macronutrients presented the following order: N˃K˃S˃P˃Mg˃Ca.


Os estudos sobre o estado nutricional da pimenta habanero (Capsicum chinense Jacq.) em relação à adubação orgânica ainda são incompletos e preliminares. O objetivo do estudo foi avaliar o efeito de doses de adubo orgânico produzido a partir de resíduos da agricultura familiar no crescimento e estado nutricional da pimenta habanero. O experimento foi conduzido em casa de vegetação localizada na Universidade Federal rural da Amazônia, município de Belém, Estado do Pará, Brasil. Foi utilizado o delineamento inteiramente casualizado (DIC), com cinco tratamentos e quatro repetições. Cada parcela experimental foi composta por um vaso com volume de 3,6 dm3de solo, no qual foram semeadas as sementes. Foram testadas cinco doses de adubo orgânico: 0%, 15% (525 g), 30% (1050 g), 45% (1575 g) e 60% (2100 g) do volume do substrato, composto pela mistura de esterco de galinha (10%), esterco de pato (20%), casca de mandioca (15%), folha de mandioca (15%), palha de feijão (15%), casca de arroz (15%) e sabugo de milho (10%), misturados em proporções volumétricas no substrato. Para a mistura das diferentes quantidades de adubo orgânico, utilizou-se um Latossolo Amarelo de textura arenosa, retirado da camada superficial (0-20 cm). Os melhores resultados foram alcançados aos 103 dias utilizando a dose de 60% de adubo orgânico. O teor e acúmulo de macronutrientes nos tecidos foliares apresentaram a seguinte ordem: N˃K≥S˃Ca≥Mg˃P e N˃K˃S˃Mg˃Ca˃P. Nos frutos, o teor e acúmulo de macronutrientes apresentaram a seguinte ordem: N˃K˃S˃P˃Mg˃Ca.


Assuntos
Capsicum/crescimento & desenvolvimento , Capsicum/química , Fertilizantes/análise , Agricultura Orgânica/métodos , Nutrientes/análise
4.
Colloq. agrar. ; 17(1): 36-43, jan.-fev. 2021. graf, ilus, tab
Artigo em Inglês | VETINDEX | ID: vti-31119

RESUMO

The Physalis genus is composed of species with economic and medicinal importance, its cultivation is expanding in Brazil, and is needed research on the performance of species in different regions of the country. Thus, the objective was to characterize the growth, development and yield of Physalis angulata and Physalis ixocarpa species cultivated in three sowing seasons in Bahia's semiarid region. The days after sowing were determined for the occurrence of vegetative and reproductive stages, and the length and diameter of the main branch were evaluated weekly. At the end of cultivation, the number and total weight of fruits per plant were determined. The plants sown in April showed the best results, with acceleration in flowering, higher productivity and growth close to other producing regions, which is the best period for the cultivation of species. P. angulata is a more tolerant species and can be sown at different periods without compromising yield. High temperatures combined with scarcity of rainfall compromise the development of plants of both species of Physalis.(AU)


O gênero Physalis é composto por espécies de importância econômica e medicinal e seu cultivo está em expansão no Brasil, sendo necessárias pesquisas sobre o desempenho de espécies em diferentes regiões do país. Assim, o objetivo desse trabalho é caracterizar o crescimento, desenvolvimento e produtividade das espécies de Physalis angulata e Physalis ixocarpa cultivadas em três épocas de semeadura na região semiárida da Bahia. Os números de dias após a semeadura foram determinados para a ocorrência dos estágios vegetativo e reprodutivo, e o comprimento e o diâmetro do ramo principal foram avaliados semanalmente. Ao final do cultivo, foram determinados o número e o peso total de frutos por planta. As plantas semeadas em abril apresentaram os melhores resultados, com aceleração da floração, maior produtividade e crescimento próximo a outras regiões produtoras, sendo o melhor período para o cultivo das espécies. P. angulata é uma espécie mais tolerante e pode ser semeada em diferentes períodos sem comprometer o rendimento. Altas temperaturas combinadas com a escassez de chuvas comprometem o desenvolvimento das plantas de ambas as espécies de Physalis.(AU)


Assuntos
Physalis/crescimento & desenvolvimento , Desenvolvimento Vegetal , Estações do Ano , Zona Semiárida , Brasil
5.
Colloq. Agrar ; 17(1): 36-43, jan.-fev. 2021. graf, ilus, tab
Artigo em Inglês | VETINDEX | ID: biblio-1481616

RESUMO

The Physalis genus is composed of species with economic and medicinal importance, its cultivation is expanding in Brazil, and is needed research on the performance of species in different regions of the country. Thus, the objective was to characterize the growth, development and yield of Physalis angulata and Physalis ixocarpa species cultivated in three sowing seasons in Bahia's semiarid region. The days after sowing were determined for the occurrence of vegetative and reproductive stages, and the length and diameter of the main branch were evaluated weekly. At the end of cultivation, the number and total weight of fruits per plant were determined. The plants sown in April showed the best results, with acceleration in flowering, higher productivity and growth close to other producing regions, which is the best period for the cultivation of species. P. angulata is a more tolerant species and can be sown at different periods without compromising yield. High temperatures combined with scarcity of rainfall compromise the development of plants of both species of Physalis.


O gênero Physalis é composto por espécies de importância econômica e medicinal e seu cultivo está em expansão no Brasil, sendo necessárias pesquisas sobre o desempenho de espécies em diferentes regiões do país. Assim, o objetivo desse trabalho é caracterizar o crescimento, desenvolvimento e produtividade das espécies de Physalis angulata e Physalis ixocarpa cultivadas em três épocas de semeadura na região semiárida da Bahia. Os números de dias após a semeadura foram determinados para a ocorrência dos estágios vegetativo e reprodutivo, e o comprimento e o diâmetro do ramo principal foram avaliados semanalmente. Ao final do cultivo, foram determinados o número e o peso total de frutos por planta. As plantas semeadas em abril apresentaram os melhores resultados, com aceleração da floração, maior produtividade e crescimento próximo a outras regiões produtoras, sendo o melhor período para o cultivo das espécies. P. angulata é uma espécie mais tolerante e pode ser semeada em diferentes períodos sem comprometer o rendimento. Altas temperaturas combinadas com a escassez de chuvas comprometem o desenvolvimento das plantas de ambas as espécies de Physalis.


Assuntos
Desenvolvimento Vegetal , Estações do Ano , Physalis/crescimento & desenvolvimento , Brasil , Zona Semiárida
6.
Heliyon ; 6(10): e05206, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33088963

RESUMO

Berry production is a non-wood product worldwide recognized by its nutritional value and taste, but the most studied species are non-native commercial plants in productive areas, leaving aside native berries. We propose that native berries (Berberis microphylla G.Forst) naturally growing in degradation forests areas could diversify livestock establishment production and complement traditional uses (e.g., livestock). The aims of this work were to 1) environmentally characterize (e.g., soil nutrient content and physical conditions, air conditions and photosynthetically active radiation) in three degraded Nothofagus antarctica Oerst. forest (due to past fires and livestock use) of Tierra del Fuego; and 2) evaluate berries production of B. microphylla in terms of quality production (e.g., fruit number and weigh per shrub) and in terms of quality (individual fruit weight, fruit pulp percentage, and soluble solids content) to assess provisioning ecosystem service of this native shrub in different degraded areas. Studied sites were defined as: 1) Severe soil degradation condition (SEV) (high frequency of horses, bulls and some native guanacos year round, severe soil erosion, and shorter herbaceous layer), 2) Moderate soil degradation condition (MOD) (cattle and guanaco year round, intermediate level of soil erosion and intermediate height of herbaceous layer), and 3) Slight soil degradation condition (SLI) (livestock only during winter, but high frequency of native guanacos, lower soil erosion and taller herbaceous layer). (SEV) had the highest air and soil temperature, least soils nutrients content, highest bulk density, the least soil water content and the poorest fruit production. (MOD) had the highest soil water content and nutrient-rich soils, while (SLI) had the highest relative air humidity and PAR. B. microphylla shrubs grow with similar morphology on the different soil degraded condition. The highest fruit production were at (SLI), however the (SEV) had the highest soluble solids. We conclude that calafate shrubs in degraded Nothofagus forests offer a provisioning ecosystem service through their excellent fruits quality. Livestock farms could diversify their production through native fruits taking advantage of the altered areas occupied by B. microphylla. However, we recommend avoiding intensive livestock use in burned forests since it could lead to an irreversible soil erosion. Proper livestock management in Nothofagus burned forest could keep over the time not only the recognized ecosystem provision services (fruits, meat, wood), but also those of regulation and support that calafate shrubs offer and that make the functionality of the ecosystem.

7.
Plant Biol (Stuttg) ; 22(1): 106-112, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31433536

RESUMO

Several Cerrado tree species have traits and structures that protect from fires. The effectiveness of a trait depends on the fire regime, especially the frequency. We used Vochysia elliptica, a common Cerrado tree, as a model to test whether different fire frequencies alter crown architecture and flower, fruit and seed production. We analysed the effect of fire on the production of inflorescences, fruits and seeds, as well as seed germination and tree architecture of 20 trees in each of three plots of a long-term ecological experiment managed with different fire regimes: burned every 2 years (B), burned every 4 years (Q) in mid-dry season and an area protected from fire (C). We found a large negative effect of fire frequency on crown architecture and on flower and fruit production. Trees in C and Q had significantly more main branches and a larger crown area than trees in B. At its peak, a tree in C was expected to produce 2.4 times more inflorescences than Q, and 15.5 times more than B, with similar magnitudes for fruits. Sixty per cent of trees in B and 10% in Q produced no fruits. The differences in architecture might explain the reduction in sexual reproduction due to a smaller physical space to produce flowers at the branch apices. Resource limitation due to plant investment to replace burned vegetative parts may also decrease sexual reproduction. Our results indicate potentially severe consequences of high fire frequencies for population dynamics and species persistence in Cerrado communities.


Assuntos
Incêndios , Pradaria , Árvores , Dinâmica Populacional , Sementes/fisiologia , Árvores/anatomia & histologia , Árvores/fisiologia
8.
Plant Dis ; 103(7): 1665-1673, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31094657

RESUMO

Frosty pod rot (FPR) caused by Moniliophthora roreri is the primary disease affecting cacao production in the major producing countries of the Americas and is one of the major threats to cacao worldwide. The incidence of FPR on clones with different levels of resistance was investigated in four localities of Santander State, Colombia, between July 2013 and May 2015. Dynamics of diseased pods were modeled using boosted regression trees, a machine learning technique that allows regressions to be performed without prior statistical assumptions. The results suggested that FPR epidemics varied according to plot location, clone, weeks of observation, and total pods produced. Dynamics in the phenology of pods had an effect on the epidemics, and this dynamic could partially explain the difference in resistance among clones. Although not total, partial resistance of ICS 95 was confirmed. An important wilt effect was observed, particularly in the resistant clones; consequently, differences in harvested pods were not significant among clones. Pod stripping remains a good practice for the management of the disease and this practice could also have an effect on the pod dynamics and wilt phenomenon.


Assuntos
Agaricales , Cacau , Doenças das Plantas , Agaricales/fisiologia , Cacau/microbiologia , Colômbia , Doenças das Plantas/microbiologia
9.
R. Ci. agrovet. ; 18(3): 391-394, 2019. tab
Artigo em Português | VETINDEX | ID: vti-25801

RESUMO

O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de poda radicular sobre o crescimento vegetativo, produção e qualidade de frutos de pereira Abate Fetel. O experimento foi conduzido durante as safras 2007 e 2008. Os tratamentos consistiram em: poda radicular a 20 cm da planta, 35 cm e controle sem realização de poda radicular. A poda radicular apresentou controle do vigor e na manutenção de características vegetativas, no entanto, não influenciou os índices produtivos e físico-químicos dos frutos. Conclui-se que a poda radicular promove controle do vigor em pereira Abate Fetel.(AU)


The objective of this work was to evaluate the effect of different levels of root pruning on the vegetative growth, yield and quality of fruits of ‘Abate Fetel pear. The experiment was conducted during the cropping seasons of 2007 and 2008. The treatments consisted of: root pruning at 20 cm of the plant, 35 cm and control without root pruning. Root pruning showed vigor control and maintenance of vegetative characteristics, however, it did not influence the productive and physical-chemical indices of the fruits. It is concluded that root pruning promotes vigor control in ‘Abate Fetel pears.(AU)


Assuntos
Pyrus/crescimento & desenvolvimento , Pyrus/fisiologia , Fenômenos Fisiológicos Vegetais , Raízes de Plantas/crescimento & desenvolvimento
10.
Rev. Ciênc. Agrovet. (Online) ; 18(3): 391-394, 2019. tab
Artigo em Português | VETINDEX | ID: biblio-1488339

RESUMO

O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de poda radicular sobre o crescimento vegetativo, produção e qualidade de frutos de pereira Abate Fetel. O experimento foi conduzido durante as safras 2007 e 2008. Os tratamentos consistiram em: poda radicular a 20 cm da planta, 35 cm e controle sem realização de poda radicular. A poda radicular apresentou controle do vigor e na manutenção de características vegetativas, no entanto, não influenciou os índices produtivos e físico-químicos dos frutos. Conclui-se que a poda radicular promove controle do vigor em pereira Abate Fetel.


The objective of this work was to evaluate the effect of different levels of root pruning on the vegetative growth, yield and quality of fruits of ‘Abate Fetel’ pear. The experiment was conducted during the cropping seasons of 2007 and 2008. The treatments consisted of: root pruning at 20 cm of the plant, 35 cm and control without root pruning. Root pruning showed vigor control and maintenance of vegetative characteristics, however, it did not influence the productive and physical-chemical indices of the fruits. It is concluded that root pruning promotes vigor control in ‘Abate Fetel’ pears.


Assuntos
Fenômenos Fisiológicos Vegetais , Pyrus/crescimento & desenvolvimento , Pyrus/fisiologia , Raízes de Plantas/crescimento & desenvolvimento
11.
Am J Bot ; 105(12): 2037-2050, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30548976

RESUMO

PREMISE OF THE STUDY: Flowering initiation, duration and magnitude, and degree of flowering synchrony within a population can affect the reproductive fitness of individuals. We examined the flowering phenology within a population of the tropical dry forest Guanacaste tree (Enterolobium cyclocarpum) to gauge the impact of phenological variation among trees on fruit production and progeny vigor. METHODS: We monitored the flowering phenology of 93 trees weekly during 2005, 2006, and 2007, using a scale based on the percentage of the crown with open flowers. We also monitored fruit production for each tree in 2005, 2006, 2007, and 2008. Finally, we evaluated the relationship between phenological variation and progeny performance. KEY RESULTS: Ten measures of flowering phenology and synchrony among flowering trees, based on the number of weeks when anthesis of the crown exceeded 50%, were used to develop four phenological profiles. These profiles were correlated with significant differences in fruit production and progeny vigor. Trees with flowers in >50% of their crown for at least 2 weeks produced more fruits and more vigorous progeny than trees with other profiles. Trees also tended to produce the same phenological profile among years than predicted by chance. CONCLUSIONS: Guanacaste trees vary significantly in the initiation of anthesis, duration and magnitude of flowering, and degree of synchrony among trees. Trees also tend to maintain the same flowering profile among years. Finally, the flowering behavior of E. cyclocarpum leads to significant differences in fruit and seed production, germination, and early progeny growth.


Assuntos
Fabaceae/fisiologia , Flores/fisiologia , Árvores/fisiologia , Frutas/crescimento & desenvolvimento , Germinação , Plântula/crescimento & desenvolvimento , Fatores de Tempo
12.
Ci. Rural ; 48(9)2018.
Artigo em Inglês | VETINDEX | ID: vti-737383

RESUMO

ABSTRACT: Black shading nets are widely used in the protected cultivation of vegetables as a technique for controlling light and temperature, while the colored shading nets, with special optical properties to improve the use of solar radiation, appeared recently in the agricultural plastics market. Light quality transmitted by gray, aluminized, pearl, blue, red and black (control) nets with 30% shade was evaluated, as well as its effects on photosynthetic properties and fruits production of cucumber plants. Treatments (shade nets) were established under a randomized complete block design with four repetitions. The red net transmitted 23.7 and 40.3% more photosynthetic photon flux density (400 to 700nm) and red light (600 to 700nm) and the blue net transmitted 36% more blue light (400 to 500nm) in comparison with the respective transmissions of black net. All nets increased the photosynthetic responses: transpiration, stomatal conductance and CO2 assimilation, observed in plants grown under black net. Leaf greenness (41.6 SPAD units) and foliar area (90dm2) increased 22.8 and 38.9% with the red net, while the dry weight of leaf (52.5g) increased 21.9% with pearl net. Pearl, red, aluminized and blue nets showed to be viable alternatives because the production of fruit increased in 71, 48, 46 and 46%, respectively, in comparison with the conventional black net (52t ha-1).


RESUMO: As malhas de sombreamento preto são amplamente utilizadas no cultivo protegido de hortaliças como uma técnica para controlar a luz e a temperatura; enquanto as malhas de sombreamento coloridas, com propriedades ópticas especiais para melhorar o uso da radiação solar, apareceram recentemente no mercado de plásticos agrícolas. A qualidade de luz transmitida por malhas cinza, aluminizada, pérola, azul, vermelha e preta (controle) com 30% de sombreamento foi avaliada, assim como seus efeitos nas propriedades fotossintéticas e na produção de frutos de plantas de pepino. Os tratamentos (malhas de sombreamento) foram estabelecidos sob o desenho de blocos completos casualizados, com quatro repetições. A malha vermelha transmitiu 23,7 e 40,3% mais densidade de fluxo de fótons fotossintéticos (400 a 700nm) e luz vermelha (600 a 700nm) e a malha azul transmitiu 36% mais luz azul (400 a 500nm) em comparação com as respectivas transmissões de malha preta. Todas as malhas aumentaram as respostas fotossintéticas: transpiração, condutância estomática e assimilação de CO2, observadas em plantas cultivadas sob malha preta. O verde da folha (41,6 unidades SPAD) e a área foliar (90dm2) aumentaram 22,8 e 38,9% com a malha vermelha, enquanto o peso seco da folha (52,5g) aumentou 21,9% com a malha pérola. As malhas pérola, vermelha, aluminizada e azul mostraram-se como alternativas viáveis, pois a produção de frutos aumentou em 71, 48, 46 e 46%, respectivamente, em comparação à malha convencional preta (52t ha-1).

13.
Ci. Rural ; 48(9): e20170829, 2018. graf, tab
Artigo em Inglês | VETINDEX | ID: vti-736456

RESUMO

Black shading nets are widely used in the protected cultivation of vegetables as a technique for controlling light and temperature, while the colored shading nets, with special optical properties to improve the use of solar radiation, appeared recently in the agricultural plastics market. Light quality transmitted by gray, aluminized, pearl, blue, red and black (control) nets with 30% shade was evaluated, as well as its effects on photosynthetic properties and fruits production of cucumber plants. Treatments (shade nets) were established under a randomized complete block design with four repetitions. The red net transmitted 23.7 and 40.3% more photosynthetic photon flux density (400 to 700nm) and red light (600 to 700nm) and the blue net transmitted 36% more blue light (400 to 500nm) in comparison with the respective transmissions of black net. All nets increased the photosynthetic responses: transpiration, stomatal conductance and CO2 assimilation, observed in plants grown under black net. Leaf greenness (41.6 SPAD units) and foliar area (90dm2) increased 22.8 and 38.9% with the red net, while the dry weight of leaf (52.5g) increased 21.9% with pearl net. Pearl, red, aluminized and blue nets showed to be viable alternatives because the production of fruit increased in 71, 48, 46 and 46%, respectively, in comparison with the conventional black net (52t ha-1).(AU)


As malhas de sombreamento preto são amplamente utilizadas no cultivo protegido de hortaliças como uma técnica para controlar a luz e a temperatura; enquanto as malhas de sombreamento coloridas, com propriedades ópticas especiais para melhorar o uso da radiação solar, apareceram recentemente no mercado de plásticos agrícolas. A qualidade de luz transmitida por malhas cinza, aluminizada, pérola, azul, vermelha e preta (controle) com 30% de sombreamento foi avaliada, assim como seus efeitos nas propriedades fotossintéticas e na produção de frutos de plantas de pepino. Os tratamentos (malhas de sombreamento) foram estabelecidos sob o desenho de blocos completos casualizados, com quatro repetições. A malha vermelha transmitiu 23,7 e 40,3% mais densidade de fluxo de fótons fotossintéticos (400 a 700nm) e luz vermelha (600 a 700nm) e a malha azul transmitiu 36% mais luz azul (400 a 500nm) em comparação com as respectivas transmissões de malha preta. Todas as malhas aumentaram as respostas fotossintéticas: transpiração, condutância estomática e assimilação de CO2, observadas em plantas cultivadas sob malha preta. O verde da folha (41,6 unidades SPAD) e a área foliar (90dm2) aumentaram 22,8 e 38,9% com a malha vermelha, enquanto o peso seco da folha (52,5g) aumentou 21,9% com a malha pérola. As malhas pérola, vermelha, aluminizada e azul mostraram-se como alternativas viáveis, pois a produção de frutos aumentou em 71, 48, 46 e 46%, respectivamente, em comparação à malha convencional preta (52t ha-1).(AU)


Assuntos
Cucumis sativus/crescimento & desenvolvimento , Fotossíntese , Processos Fotoquímicos , Luz Solar
14.
Ciênc. rural (Online) ; 48(9): e20170829, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1045200

RESUMO

ABSTRACT: Black shading nets are widely used in the protected cultivation of vegetables as a technique for controlling light and temperature, while the colored shading nets, with special optical properties to improve the use of solar radiation, appeared recently in the agricultural plastics market. Light quality transmitted by gray, aluminized, pearl, blue, red and black (control) nets with 30% shade was evaluated, as well as its effects on photosynthetic properties and fruits production of cucumber plants. Treatments (shade nets) were established under a randomized complete block design with four repetitions. The red net transmitted 23.7 and 40.3% more photosynthetic photon flux density (400 to 700nm) and red light (600 to 700nm) and the blue net transmitted 36% more blue light (400 to 500nm) in comparison with the respective transmissions of black net. All nets increased the photosynthetic responses: transpiration, stomatal conductance and CO2 assimilation, observed in plants grown under black net. Leaf greenness (41.6 SPAD units) and foliar area (90dm2) increased 22.8 and 38.9% with the red net, while the dry weight of leaf (52.5g) increased 21.9% with pearl net. Pearl, red, aluminized and blue nets showed to be viable alternatives because the production of fruit increased in 71, 48, 46 and 46%, respectively, in comparison with the conventional black net (52t ha-1).


RESUMO: As malhas de sombreamento preto são amplamente utilizadas no cultivo protegido de hortaliças como uma técnica para controlar a luz e a temperatura; enquanto as malhas de sombreamento coloridas, com propriedades ópticas especiais para melhorar o uso da radiação solar, apareceram recentemente no mercado de plásticos agrícolas. A qualidade de luz transmitida por malhas cinza, aluminizada, pérola, azul, vermelha e preta (controle) com 30% de sombreamento foi avaliada, assim como seus efeitos nas propriedades fotossintéticas e na produção de frutos de plantas de pepino. Os tratamentos (malhas de sombreamento) foram estabelecidos sob o desenho de blocos completos casualizados, com quatro repetições. A malha vermelha transmitiu 23,7 e 40,3% mais densidade de fluxo de fótons fotossintéticos (400 a 700nm) e luz vermelha (600 a 700nm) e a malha azul transmitiu 36% mais luz azul (400 a 500nm) em comparação com as respectivas transmissões de malha preta. Todas as malhas aumentaram as respostas fotossintéticas: transpiração, condutância estomática e assimilação de CO2, observadas em plantas cultivadas sob malha preta. O verde da folha (41,6 unidades SPAD) e a área foliar (90dm2) aumentaram 22,8 e 38,9% com a malha vermelha, enquanto o peso seco da folha (52,5g) aumentou 21,9% com a malha pérola. As malhas pérola, vermelha, aluminizada e azul mostraram-se como alternativas viáveis, pois a produção de frutos aumentou em 71, 48, 46 e 46%, respectivamente, em comparação à malha convencional preta (52t ha-1).

15.
Oecologia ; 184(2): 531-541, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28477048

RESUMO

The response of tropical forests to anthropogenic climate change is critically important to future global carbon budgets, yet remains highly uncertain. Here, we investigate how precipitation, temperature, solar radiation and dry- and wet-season lengths are related to annual tree growth, flower production, and fruit production in three moist tropical forest tree species using long-term datasets from tree rings and litter traps in central Panama. We also evaluated how growth, flower, and fruit production were interrelated. We found that growth was positively correlated with wet-season precipitation in all three species: Jacaranda copaia (r = 0.63), Tetragastris panamensis (r = 0.39) and Trichilia tuberculata (r = 0.39). Flowering and fruiting in Jacaranda were negatively related to current-year dry-season rainfall and positively related to prior-year dry-season rainfall. Flowering in Tetragastris was negatively related to current-year annual mean temperature while Trichilia showed no significant relationships of reproduction with climate. Growth was significantly related to reproduction only in Tetragastris, where it was positively related to previous year fruiting. Our results suggest that tree growth in moist tropical forest tree species is generally reduced by drought events such as those associated with strong El Niño events. In contrast, interannual variation in reproduction is not generally associated with growth and has distinct and species-specific climate responses, with positive effects of El Niño events in some species. Understanding these contrasting climate effects on tree growth and reproduction is critical to predicting changes in tropical forest dynamics and species composition under climate change.


Assuntos
Mudança Climática , Árvores/crescimento & desenvolvimento , Clima Tropical , Clima , Panamá , Reprodução , Estações do Ano
16.
Am J Bot ; 103(11): 1990-1999, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27864261

RESUMO

PREMISE OF THE STUDY: Factors related to pollen and resource limitation were evaluated to predict female fruit production in a tropical dioecious tree. Pollen limitation via variation in the male density at local scales is expected to limit female reproduction success in dioecious plants. METHODOLOGY: We modeled the roles of local male density, female crown size, crown illumination, and female flower production on female fruit initiation and mature fruit production in a continuous population (62 ha plot) of a tropical dioecious tree (Virola surinamensis). In addition, we used microsatellites to describe the scale of effective pollen flow, the male effective population size, and the spatial genetic structure within/between progenies and males. KEY RESULTS: The local male density was not related to female fruit initiation or mature fruit production. Female floral production had a positive effect on fruit initiation. The female crown size was positively related to fruit maturation. Seeds from the same female and seeds from different but spatially proximal females were generally half-siblings; however, proximal females showed greater variation. Proximal male-female adult pairs were not significantly more genetically related than distant pairs. The probability of paternity was negatively affected by the distance between seeds and males; most effective pollen dispersal events (∼85%) occurred from males located less than 150 m from females. The number of males siring progenies was greater than the number of males found at local scales. CONCLUSIONS: Female fecundity in this continuous population of Virola surinamensis is not limited by the availability of pollen from proximal males. Rather, resource allocation to floral production may ultimately determine female reproductive success.


Assuntos
Flores/fisiologia , Myristicaceae/fisiologia , Demografia , Flores/genética , Flores/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/fisiologia , Geografia , Myristicaceae/genética , Myristicaceae/crescimento & desenvolvimento , Pólen/genética , Pólen/crescimento & desenvolvimento , Pólen/fisiologia , Polinização , Densidade Demográfica , Reprodução , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia
17.
Ci. Rural ; 46(9): 1509-1513, Sept. 2016. tab
Artigo em Inglês | VETINDEX | ID: vti-29652

RESUMO

ABSTRACT: The aim of this study was to conduct a survey on nematodes associated with five cultivated fruit trees growing in the Agroforestry System (AFS) of the municipality of Oiapoque, Amapá, Brazil. Rhizosphere samples were collected from three points at the base of murici ( Byrsonima sp.), soursop ( Annona muricata ), cupuaçu ( Theobroma grandiflorum ), passion fruit ( Passiflora sp.) and peach palm ( Bactris gasipaes ) trees. Four species of phytonematodes were identified, namely Pratylenchus brachyurus, Helicotylenchus dihystera, Mesocriconema xenoplax and Rotylenchulus reniformis . The most prevalent and abundant species was R. reniformis , which was found in the rhizospheres of passion fruit, cupuaçu, soursop, and peach palm. The first record in Brazil of the nematode P. brachyurus , found in the roots of murici is reported here, and all of the nematode species identified here are the first records for fruit trees in the state of Amapá.(AU)


Este estudo teve como objetivo o levantamento de nematoides, associados a cinco fruteiras cultivadas em Sistema Agroflorestal (SAF), no município de Oiapoque, AP. Amostras da rizosfera foram coletadas em três pontos, na base de plantas de murici ( Byrsonima sp.), graviola ( Annona muricata ), cupuaçu ( Theobroma grandiflorum ), maracujá ( Passiflora sp.) e pupunha ( Bactris gasipaes ). Foram constatadas quatro espécies de fitonematoides: Pratylenchus brachyurus, Helicotylenchus dihystera, Mesocriconema xenoplax e Rotylenchulus reniformis . A espécie mais prevalente e abundante foi R . reniformis , encontrado na rizosfera de maracujá, cupuaçu, graviola e pupunha. Foi relatado o primeiro registro de P. brachyurus em raízes de muricizeiro no Brasil e todas as espécies encontradas configuram-se como primeiros registros de fitonematoides em fruteiras no estado do Amapá.(AU)


Assuntos
Frutas/parasitologia , Nematoides/patogenicidade , Pragas da Agricultura , Annona , Passiflora , Arecaceae
18.
Ciênc. rural ; Ciênc. rural (Online);46(9): 1509-1513, tab
Artigo em Inglês | LILACS | ID: lil-787403

RESUMO

ABSTRACT: The aim of this study was to conduct a survey on nematodes associated with five cultivated fruit trees growing in the Agroforestry System (AFS) of the municipality of Oiapoque, Amapá, Brazil. Rhizosphere samples were collected from three points at the base of murici ( Byrsonima sp.), soursop ( Annona muricata ), cupuaçu ( Theobroma grandiflorum ), passion fruit ( Passiflora sp.) and peach palm ( Bactris gasipaes ) trees. Four species of phytonematodes were identified, namely Pratylenchus brachyurus, Helicotylenchus dihystera, Mesocriconema xenoplax and Rotylenchulus reniformis . The most prevalent and abundant species was R. reniformis , which was found in the rhizospheres of passion fruit, cupuaçu, soursop, and peach palm. The first record in Brazil of the nematode P. brachyurus , found in the roots of murici is reported here, and all of the nematode species identified here are the first records for fruit trees in the state of Amapá.


RESUMO: Este estudo teve como objetivo o levantamento de nematoides, associados a cinco fruteiras cultivadas em Sistema Agroflorestal (SAF), no município de Oiapoque, AP. Amostras da rizosfera foram coletadas em três pontos, na base de plantas de murici ( Byrsonima sp.), graviola ( Annona muricata ), cupuaçu ( Theobroma grandiflorum ), maracujá ( Passiflora sp.) e pupunha ( Bactris gasipaes ). Foram constatadas quatro espécies de fitonematoides: Pratylenchus brachyurus, Helicotylenchus dihystera, Mesocriconema xenoplax e Rotylenchulus reniformis . A espécie mais prevalente e abundante foi R . reniformis , encontrado na rizosfera de maracujá, cupuaçu, graviola e pupunha. Foi relatado o primeiro registro de P. brachyurus em raízes de muricizeiro no Brasil e todas as espécies encontradas configuram-se como primeiros registros de fitonematoides em fruteiras no estado do Amapá.

19.
Am J Primatol ; 78(4): 391-401, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26684405

RESUMO

Undisturbed primate communities in the Neotropics are bottom-up structured as their biomass and species richness can be predicted from fruit production. However, the effects of fruit scarcity and the availability of forest types have not been fully analyzed, and seasonality is expected to differently affect small and large monkeys. The first aim of this study was to examine the effect of contrasting forest types within a location on the temporal variation in fruit production. The second was to assess the relative roles of disturbance, climate, patterns of fruit and leaf production, and plant composition on determining Neotropical primate communities. I compiled population density data for diurnal primate species from 154 sites to calculate species richness and assemblage biomass. Fruit abundance in the study sites was estimated from fruit trap data and phenology transects, and fruit variability was calculated as the monthly coefficient of variation (CV) and the length of the fruit scarcity period (LFSP). The results indicate that fruit production in floodplain forests is generally more variable than in terra firme forests, and this variation decreases in habitats with mixed forest types. Endozoochorous fruit production (based on fruit traps) and litter productivity were good predictors of the biomass of Neotropical primates (R2 = 0.83 and R2 = 0.59, respectively), but neither CV nor LFSP were good predictors. The biomass of large primates was independent of rainfall variation, but the biomass of small and medium sized monkeys was negatively correlated with temporal rainfall variability. Varzea forests tended to show higher biomass than those from terra firme and igapó. These results suggest that the production of fleshy fruits is the best predictor of the structure of primate assemblages in the Neotropics, but the effect of leaf quality and productivity remains to be investigated. Am. J. Primatol. 78:391-401, 2016. © 2015 Wiley Periodicals, Inc.

20.
Braz. J. Biol. ; 75(4,supl.1): 88-96, Nov. 2015. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-378884

RESUMO

The ecology of seed dispersal is critical to understand the patterns of distribution and abundance of plant species. We investigated seed dispersal aspects associated with the high abundance of Buchenavia tomentosa in the Serra Azul State Park (PESA). We estimated fruit production and conducted fruit removal experiments. We carried out diurnal and nocturnal observations on frugivory as well as germination tests. Fruiting occurred in the dry season and totaled 1,365,015 ± 762,670 fruits.ha–1. B. tomentosa fruits were utilized by eight animal species. The lowland tapir (Tapirus terrestris) was considered the main seed disperser. Leafcutter ants (Atta laevigata and Atta sexdens) participated in the seed cleaning and occasionally dispersed seeds. The beetle Amblycerus insuturatus, blue-and-yellow macaw (Ara ararauna) and red-and-green macaw (Ara chloropterus) were considered pre-dispersal seed predators. The seeds manually cleaned presented higher germination rate (100%) and speed index (4.2 seeds.d–1) than that of seeds with pulp. Germination of seeds found in tapirsfeces was 40%, while for the seeds without pulp it was 25%. The high abundance of B. tomentosa in the cerrado of PESA may be due to massive fruit production, low rates of seed predation, and efficient seed dispersal by tapirs, occurring before the rains which promote germination and recruitment of this species.(AU)


A ecologia da dispersão de sementes é importante para entender a distribuição e abundância das espécies vegetais. Investigamos os fatores relacionados à elevada abundância de B. tomentosa no Parque Estadual da Serra Azul (PESA) avaliando aspectos da dispersão de sementes. Estimamos a produção de frutos e realizamos experimentos de remoção de frutos. Fizemos observações diurnas e noturnas sobre a frugivoria e testamos a germinação de sementes. A frutificação ocorreu na estação seca totalizando 1.365.015 ± 762.670 frutos.ha–1. Oito espécies de animais utilizaram frutos de B. tomentosa. Anta (Tapirus terrestris) foi considerada o principal dispersor. Saúvas (Atta laevigata e Atta sexdens) participaram na limpeza das sementes e como dispersores ocasionais. O besouro Amblycerus insuturatus, arara-canindé (Ara ararauna) e arara-vermelha (Ara chloropterus) foram considerados predadores pré-dispersão. Sementes despolpadas manualmente tiveram maior percentual (100%) e velocidade de geminação (4,2 sementes.dia–1) que aquelas com polpa. Sementes encontradas nas fezes de antas apresentaram 40,0% de germinação e sementes sem polpa 25,0%. A massiva produção de frutos, baixa taxa de predação de sementes, além da eficiente dispersão por antas, antes da estação chuvosa, favorecem o recrutamento e são fatores que contribuem de forma decisiva para a elevada abundância de B. tomentosa observada no cerrado do PESA.(AU)


Assuntos
Animais , Formigas/fisiologia , Combretaceae/fisiologia , Comportamento Alimentar , Papagaios/fisiologia , Perissodáctilos/fisiologia , Dispersão de Sementes , Brasil , Cadeia Alimentar , Germinação , Pradaria
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA