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Plasticidade fenotípica de Aloysia citrodora: alterações anatômicas na disponibilidade de água e estações do ano
No full textThe objective was to evaluate the anatomical changes of the leaves of Aloysia citrodora submitted to different water availability during the seasons. The experiment was conducted in a greenhouse, in a randomized block design, bifactorial 4x4, with four seasonal factors (autumn, winter, spring, and summer) and simulations of water availability (25, 50, 75 and 100% of field capacity) with four repetitions. They were evaluated in μm: the thickness of the adaxial and abaxial cuticles, adaxial and abaxial epidermis, palisade and lacunous parenchyma, mesophyll and leaf thickness of the transversal section and the mesophyll and thickness of the main rib and the length and width of the vascular system. In the autumn season, there was a reduction in the width of the vascular system and the thickness of the adaxial cuticle under greater water availability. In winter and under low water availability, there was a reduction in the thickness of the cuticle and adaxial epidermis, lacunous parenchyma, mesophyll and leaf thickness, mesophyll and main rib thickness. In the spring with greater water availability increased in the adaxial and abaxial epidermis, mesophyll and thickness of the main rib, and length of the vascular system; and low water availability provided the greater thickness of the adaxial cuticle, palisade parenchyma, and leaf thickness. In the summer season with the greatest water availability, there was an increase in leaf thickness and adaxial cuticle and a reduction in palisade parenchyma, while low water availability increased the thickness of leaf mesophyll.O objetivo foi avaliar as alterações anatômicas das folhas de Aloysia citrodora submetidas a diferentes disponibilidades hídricas e estações do ano. O experimento foi conduzido em casa de vegetação, no delineamento de blocos casualizados, bifatorial 4x4, com quatro fatores sazonais (outono, inverno, primavera e verão) e simulações de disponibilidade hídrica (25, 50, 75 e 100% da capacidade de campo) com quatro repetições. Foram avaliados em μm: a espessura das cutículas adaxial e abaxial, epiderme adaxial e abaxial, parênquima paliçadico e lacunoso, mesofilo e espessura da folha da seção transversal e o mesofilo e espessura da nervura principal e o comprimento e largura do sistema vascular. No outono, houve redução da largura do sistema vascular e da espessura da cutícula adaxial sob maior disponibilidade hídrica. No inverno com baixa disponibilidade hídrica, houve redução da espessura da cutícula e da epiderme adaxial, parênquima lacunoso, mesofilo e espessura foliar, mesofilo e espessura da nervura principal. Na primavera com maior disponibilidade hídrica aumentou a epiderme adaxial e abaxial, mesofilo e espessura da nervura principal e comprimento do sistema vascular; e a baixa disponibilidade hídrica proporcionou maior espessura da cutícula adaxial, parênquima paliçádico e espessura foliar. No verão com maior disponibilidade hídrica, houve aumento da espessura foliar e da cutícula adaxial e redução do parênquima paliçádico, enquanto a baixa disponibilidade hídrica aumentou a espessura do mesofilo foliar
Aplicação conjunta de fungicida e rizobactérias em sementes de tomate
No full textTomato (Lycopersicon esculentum) is a vegetable that stands out among the others for being one of the most consumed and industrialized. Among the technologies for increasing crop productivity, the treatment of seeds with fungicides and or rhizobacteria that promotes plant growth stands out. The objective of the work was to evaluate the effect of the combined application of fungicide and rhizobacteria on the germination and vigor of tomato seeds. The assays were mounted in DIC in a factorial scheme 10 x 2 + 1 (10 rhizobacteria, with or without fungicide and additional treatment: fungicide only), with four replications. The following characteristics were evaluated: water content, germination, first germination count, germination speed index (IVG), seedling emergence and accelerated aging. In general, the treatment of seeds with rhizobacteria stimulates the physiological quality of tomato seeds. The rhizobacteria Paenibacillus lentimorbus-69 and Bacillus subtilis-34 proved to be compatible with the fungicide, favoring the germination and vigor of the seeds in relation to the treatment with fungicideO tomate é uma hortaliça que se destaca entre as demais por ser uma das mais consumidas e industrializadas. Dentre as tecnologias para aumento da produtividade das culturas se destaca o tratamento de sementes com fungicidas e ou rizobactérias promotoras de crescimento de plantas. O objetivo do trabalho foi avaliar o efeito da aplicação conjunta de fungicida e rizobactérias na germinação e no vigor de sementes de tomate. Os ensaios foram montados em DIC em esquema fatorial 10 x 2 + 1 (10 rizobactérias, com ou sem fungicida e tratamento adicional: apenas fungicida), com quatro repetições. As seguintes características foram avaliadas: teor de água, germinação, primeira contagem da germinação, índice de velocidade de germinação (IVG), emergência de plântulas e envelhecimento acelerado. De maneira geral, o tratamento de sementes com rizobactérias estimula a qualidade fisiológica de sementes de tomate. As rizobactérias Paenibacillus lentimorbus-69 e Bacillus subtilis-34 mostraram-se compatíveis com o fungicida favorecendo a germinação e o vigor das sementes em relação ao tratamento com fungicida
The Agronomic efficiency of the inoculant FT10 (Trichoderma asperelloides) on four lettuce varieties
No full textThe present study aimed to evaluate the agronomic efficiency of FT10 (Trichoderma asperelloides) on lettuce varieties development and productivity throughout the year. Four greenhouse experiments were carried out to verify the effect of three doses of the bio-product on plant growth and yield on loose-leaf, butterhead, iceberg and salad bowl cultivars. A randomized block design was used, with six replications. The treatments were: 1) control, 2) 30.0 x 1012 CFU.ha-1 of the commercial inoculant ICB Nutrisolo ® Trichoderma, 3) 5.0 x 1011 CFU.ha-1 of FT10 inoculant, 4) 10.0 x 1011 CFU.ha-1 of FT10, and 5) 15.0 x 1011 CFU.ha-1 of FT10. Plant dry weight and yield were evaluated 42 DAT. The data obtained were compared with Duncan\u27s test. Significant increases in yield in up to 21% for loose-leaf and 16% for butterhead were observed with the dose of 15.0 x 1011 CFU.ha-1 and 22% for iceberg and salad bowl with the dose of 10.0 x 1011 CFU.ha-1 of FT10. It can be concluded that FT10 has the potential to promote plant growth and increase the productivity of lettuce cultivars if applied the appropriate dose of the product.
 
A modalidade de aplicação afeta a seletividade de herbicidas para a cultura do alho
No full textChemical control is the main weed control method in garlic crops; however, this crop is sensitive to herbicides, which can cause injuries and decrease yield depending on the products used, application timing, rate, and cultivar. In this context, the objective of this study was to evaluate the selectivity of herbicides for garlic plants (cultivar Chonan), using different application timings. A greenhouse experiment was conducted in a completely randomized design with four replications. An 8×2 factorial arrangement was used, in which the first factor consisted of a control without herbicide and seven herbicides (linuron, diuron, pendimethalin, s-metolachlor, oxyfluorfen, flumioxazin, and oxadiazon) applied according to the second factor, application timings (preemergence or post-emergence). Phytotoxicity, photosynthetic rate, stomata morphometry, bulb diameter, and crop yield of garlic were evaluated. Pre-emergence applications were more selective than post emergence applications. The herbicides linuron, diuron, s-metolachlor, and oxadiazon applied at pre-emergence, and s-metolachlor, oxyfluorfen, flumioxazin, and oxadiazon applied at post-emergence were not selective for the Chonan garlic cultivar. Pendimethalin presented the highest selectivity, regardless of the application timing. Oxyfluorfen and flumioxazin applied at pre-emergence and linuron and diuron applied at post-emergence were selective for the cultivar Chonan.O principal método de controle de plantas daninhas na cultura do alho é o químico, contudo essa cultura é extremamente sensível à herbicidas, podendo sofrer injúrias e redução de produtividade dependendo dos produtos utilizados, modalidade de aplicação, dose, cultivar, dentre outros. Assim o objetivo do presente estudo foi avaliar a seletividade de herbicidas para a cultura do alho cultivar Chonan, aplicados em diferentes modalidades de aplicação. Para isso foi conduzido, em casa de vegetação, um experimento em delineamento inteiramente casualizado, com quatro repetições. O experimento contou com 16 tratamentos, dispostos em esquema fatorial 8 x 2. O primeiro fator é representado por uma testemunha sem herbicida e sete herbicidas (linuron, diuron, pendimethalin, s-metolachlor, oxyfluorfen, flumioxazin e oxydiazon), e o segundo fator pela modalidade de aplicação (pré-emergência ou pós emergência). Foi avaliado a fitointoxicação, taxa fotossintética, morfometria de estômatos, diâmetro de bulbos e produtividade da cultura do alho. As aplicações em pré-emergência foram mais seletivas em comparação com as de pós emergência. Os herbicidas linuron, diuron, s-metolachlor e oxadiazon aplicados na pré emergência e s-metolachlor, oxyfluorfen, flumioxazin e oxadiazon em pós-emergência não foram seletivos para o alho, cultivar Chonan. O pendimethalin foi o herbicida que apresentou a maior seletividade, independentemente da época de aplicação. Enquanto que oxyfluorfen e flumioxazin foram seletivos quando aplicados em pré-emergência e linuron e diuron em pós emergência do alho cultivar Chonan
Produtividade, custo e rentabilidade de couve produzida sob túnel baixo
No full textThis study evaluated the productivity and profitability of kale hybrids cultivated either in a low tunnel or an open field. The study was conducted using two hybrids of Hi-crop and Kobe kale and six environments: low tunnels covered with agrotextiles at a weight of 15 g.m-2, white organza at a weight of 47 g.m-2, 35% red screen, 35% thermo-reflective screen, 35% black screen, or an open field, with four repetitions. The total operating cost and economic indicators related to the cultivation of each hybrid and environment were calculated by estimatingthe operating profit, profitability index (%), gross margin (%), and leveling points (kg.h-1 and price. pack-1). Both hybrids showed high productivity and profitability indices in all environments. The hybrid ‘Hi-crop’ showed the highest productivity when cultivated under the organza tunnel, with a 26% greater value than that in the open field. The use of a protected environment reduced the need for insecticides, which was reflected in productivityand, consequently, in the profitability of the crops.A couve é uma hortaliça bastante popular no mundo, no entanto a ocorrência de insetos-praga pode comprometer a produção e a rentabilidade da cultura. Desta forma, objetivou-se avaliar a produtividade e a rentabilidade de dois híbridos de couve cultivados sob túnel baixo e campo aberto. O estudo foi realizado utilizando-se dois híbridos de couve folha Hi-crop e Kobe e seis ambientes: túneis baixos cobertos com agrotêxtil na gramatura 15 g/m2, organza branca na gramatura 47 g/m2, tela vermelha (Chromatinet® 35%), tela termorefletora prata (Aluminet® 35%), tela preta (Sombrite® 35%) e campo aberto, com quatro repetições. Foram realizadas seis colheitas e a somatória das médias foi utilizada para a estimativa da produtividade para cada ambiente. Calculou-se o custo operacional total e os indicadores econômicos referentes ao cultivo de cada híbrido e ambiente, estimando-se o lucro operacional, índice de lucratividade (%), margem bruta (%), ponto de nivelamento em quilos por hectare e ponto de nivelamento para estabelecimento do valor a ser aplicado na comercialização do maço do produto. Ambos os híbridos apresentaram elevada produtividade e índices de rentabilidade em todos os ambientes. O híbrido ‘Hi-crop’ apresentou a maior produtividade quando cultivado sob túnel de organza. O uso de ambiente protegido proporcionou redução na necessidade de pulverização de inseticida o que refletiu na produtividade e consequentemente na rentabilidade dos cultivos
Cnidoscolus blistering yellow mosaic virus: a new begomovirus isolated from Cnidoscolus urens in Brazil
Get PDFMembers of the genus Begomovirus have circular single-strand DNA genome encapsidated into quasi-icosahedral particles, which are transmitted by the Bemisia tabaci complex, with non-cultivated hosts acting as reservoirs for these viruses. In this study a new begomovirus infecting Cnidoscolus urens (Euphorbiaceae) from Brazil has been characterized. The complete DNA-A sequence was used for species demarcation, phylogenetic and recombination analyzes with other previously reported begomoviruses. The DNA-A (2585 nt) has a genome organization that is typical of the New World bipartite begomovirus, most closely related to tomato yellow spot virus, with 80.6% nucleotide identity. Based on the identity criterion for DNA-A established by the Geminiviridae Study Group of the International Committee on Taxonomy of Viruses of ≥ 91%, this isolate should be considered a member of a new species, for which the name “Cnidoscolus blistering yellow mosaic virus” (CnBYMV) is proposed. Phylogenetic analysis revealed that CnBYMV grouped with begomoviruses described in cultivated and non-cultivated plants from Brazil. Results of recombination analysis indicated that the novel begomovirus was a recombinant, with cnidoscolus mosaic leaf deformation virus and sida mottle virus as probable parents
Cytokinins induce the development of Campomanesia pubescens root cuttings
Get PDFThe gabirobeira (Campomanesia pubescens) is a species native to Brazilian Cerrado with great potential but is threatened to extinction and remains wild. The nursery plant production is an alternative to solve those problems and the use of plant growth regulators can support vegetative propagation. The objective of this work was to evaluate the effect of cytokinin concentrations on the vegetative propagation of C. pubescens root cuttings. The concentrations of the cytokinin 6-Benzylaminopurine were: 0.0 (Control), 1.0; 2.0 and 4.0 mg L-1 diluted in NaOH solution (6 mol L-1). The cuttings with standard size of 5 cm were dipped in the concentrations for 15 seconds and transplanted in bags containing the substrate Bioplant. After 140 days the number of shoots, length of the shoots, number of leaves, length of the leaves, the diameter of the main stem, the diameter of the main root, the total number of roots, length of the main root, total fresh matter and total dry matter, were evaluated. The experiment was conducted in a completely randomized design, with fifteen replicates per treatment. The data were submitted to analysis of variance and the effects of the concentrations tested and adjusted by regression equations. The lower concentrations of cytokinin were beneficial to the development of the cuttings, while higher concentrations inhibited their development
Gas exchanges in the zucchini culture fertilized with biofertilizers in two types of soil
Get PDFThe application of biofertilizers may provide plants similar performance and even superior to the use of mineral fertilizers, therefore, the determination of the most suitable sources to be applied in different crops is relevant. Given the importance of gas exchange in the performance of crops and that biofertilizers can provide increases in these physiological parameters, this study aimed to evaluate gas exchange in zucchini plants cultivated in two types of soil and managed with different aerobic fermentation biofertilizers. The experiment was carried out in full sunlight, in pots, using a randomized blocks design in an arrangement of split plots. The plots consisted of two types of soil (S1: Red-Yellow Argisol and S2: Fluvic Neossol), subdivided plots into five aerobic fermentation biofertilizers (F1 = quail, F2 = sheep, F3 = mixed - bovine + quail + sheep, F4 = bovine, and F5 = enriched crab), with five replicates. At 45 days after transplanting, the following variables were analyzed: photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, leaf temperature, and chlorophyll. Bovine, sheep, and mixed biofertilizers showed the highest rates with the best performance of Italian zucchini cultivation. The types of soil studied concerning the rates did not have a significant effect between treatments on zucchini cultivation. Moreover, Chlorophyll was not significantly influenced by any of the treatments applied.A aplicação de biofertilizantes pode proporcionar às plantas desempenho semelhante e até mesmo superior à aplicação de fertilizantes minerais, sendo de considerável importância a determinação das fontes mais adequadas a serem aplicadas nas diferentes culturas. Sabendo-se da importância das trocas gasosas no desempenho das culturas e que os biofertilizantes podem proporcionar incrementos nesses parâmetros fisiológicos, o presente estudo teve como objetivo avaliar as trocas gasosas em plantas de abobrinha cultivada em dois tipos de solo e adubadas com diferentes biofertilizantes de fermentação aeróbia. O experimento foi desenvolvido a pleno sol, em vasos, utilizando o delineamento em blocos ao acaso em parcelas subdivididas. As parcelas se constituíram de dois tipos de solo (S1: Argissolo Vermelho Amarelo e S2: Neossolo Flúvico) e as parcelas subdivididas, constituíram-se em cinco biofertilizantes de fermentação aeróbia (F1 = codorna, F2 = ovino, F3 = misto - bovino + codorna + ovino, F4 = bovino e F5 = caranguejo enriquecido), com cinco repetições. Aos 45 dias após o transplantio foram analisadas as seguintes variáveis: fotossíntese, condutância estomática, transpiração, concentração interna de CO2, temperatura foliar e a clorofila. Os biofertilizantes bovino, ovino e misto apresentaram as maiores taxas com melhor desempenho no cultivo da abobrinha italiana. Os tipos de solo estudado em relação às taxas não apresentaram efeito significativo entre os tratamentos no cultivo da abobrinha. A clorofila não foi influenciada significativamente por nenhum dos tratamentos aplicados
Physiological and productive performance of papaya plants irrigated in a semiarid environment
Get PDFPapaya tree has great economic importance and potential of cultivation in semiarid environment. However, water scarcity in this region may inhibits photosynthetic activity and limit the production of this crop, being necessary to use strategies of irrigation management that rationalize water and allow the production of the plants without affecting photosynthetic activity. In this sense, this study aimed to evaluate the physiological and productive performance of papaya “Calimosa” under different water replacement rates in semiarid environment. Papaya plants were irrigated with four water replacement rates (50, 75, 100 and 125% ETo) from 30 days after transplant of seedlings to the experimental area. At 10 months after transplant were realized evaluations of gas exchange and chlorophyll fluorescence, and at 12 months after transplant, it was started harvesting fruits to determine the yield. Water replacement rates significantly influenced the parameters of gas exchange of papaya with better results on rates of 125% ETo. However, application of water replacement rates of 100% ETo provide conditions adequate for the activity of gas exchange and better quantum efficiency of photosystem II, that contribute to fruit production in papaya. With rates less than 75% ETo occur drastic reductions in gas exchange, quantum efficiency of photosystem II, and fruit production of papaya, which impairs its cultivation in semiarid environments
Dynamic controlled atmosphere: A review of methods for monitoring fruit responses to low oxygen
Get PDFThe storage of fruit at minimum oxygen condition is crucial for optimal fruit quality maintenance. However, the optimal oxygen partial pressure of fruit varies according to several factors such as species, cultivar, harvest maturity, temperature, growing season and storage period. Based on these factors, storage technologies were developed that allow for the detection of the lower oxygen limit (LOL) and the storage of fruit under the lowest optimal oxygen partial pressure. One emerging technology is known as dynamic controlled atmosphere (DCA). Commercially, there are four DCA systems used: [1] DCA based on ethanol production and accumulation (DCA-Eth); [2] DCA based on chlorophyll fluorescence (DCA-CF); DCA based on the respiratory quotient (DCA-RQ) and [4] DCA based solely on CO2 production (DCA-CD). This reviews the recent developments of these DCA systems and their effect on fruit quality. Generally, the storage of fruit under DCA has a positive effect on the overall fruit quality, with regards to reduced physiological disorders and higher flesh firmness maintenance, when compared to controlled atmosphere (CA). Evidence also shows that storing fruit under DCA-RQ and DCA-CD allowed higher volatile compound emission and concentration, which can contribute positively to fruit flavor. The DCA systems are “green storage technologies” because the system enables the increase of storage temperature and thereby saving electrical energy. Storage of apples under DCA maintains an overall fruit quality similar to CA combined with the ripening inhibitor 1-Methylcyclopropen (1-MCP), which is an interesting option for organic fruit storage. Dynamic controlled atmosphere is a recently developed storage technique and is in constant improvement. The latest developed DCA techniques (DCA-RQ and DCA-CD), in contrast to DCA-CF, allow the use of extremely low oxygen levels. In the future, new and multi-sensor DCA systems are under development, which might not just control O2 partial pressure but also temperature and other parameters to allow for more energy efficient but high quality fruit storage systems