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Yield performance of okra under potassium fertilization and number of plants per hole
Get PDFThe okra is a vegetable that responds to mineral nutrition and the plant population, with increased production. The work was carried out at the Federal University of Paraíba, in Areia-PB, with the objective of evaluating the influence of K2O doses and number of plants per pit on the yield and quality of okra, cultivating Santa Cruz, in an experimental block design randomized, with treatments distributed in a 6 x 2 factorial scheme, with six K2O doses (0, 50, 100, 150, 200 and 250 kg ha-1), and one and two plants per pit, in four replications. The values for the average mass of fruits, 16 and 18 g were reached as a function of K2O doses, with one and two plants per pit, respectively. The highest numbers of fruits per plant in okra were 45 and 56, at doses of 123.7 and 184 kg ha-1 of K2O, respectively for one and two plants per pit, and the highest fruit production per plant was 584.2 g, with two plants per pit and 250 kg ha-1 of K2O. The total fruit yield was 42.13 t ha-1, in the treatment with two plants per pit and 100 kg ha-1 of K2O, and the doses of 122.5 and 115 kg ha-1 of K2O were responsible for the higher productivity of commercial fruits in okra, 25.6 and 29.2 t ha-1, respectively, with one and two plants per pit, and the leaf K content was influenced only by K2O doses.
Keywords: Abelmoschus esculentus; mineral fertilizers; plant densit
Analysis of baculovirus spodoptera virulence in fall armyworm fed with cassava leaves
Get PDFThe fall armyworm, Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) is considered the main pest of corn (Zea mays L.) in Brazil and feeds on several other plant species, including cassava (Manihot esculenta Crantz). The food substrate influences the control efficiency of baculovirus and there aren’t studies on the effects of the application of baculovirus Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) on cassava leaves in the mortality of S. frugiperda larvae. The main objectives of this study were to evaluate the efficiency of SfMNPV isolate 6 on S. frugiperda larvae fed on corn and cassava leaves. The food substrates were treated with three baculovirus concentrations (2 x 105, 2 x 106 and 2 x 107 OB mL-1) of a semipurified suspension, and of a commercial formulation (CartuchoVit®), both containing SfMNPV isolate 6, and then were offer to S. frugiperda second instar larvae. The semipurified virus was more virulent than the commercial formulation, regardless of the food substrate provided to insects, when concentrations of 2 x 105 and 2 x 106 OB mL-1 were used. However, there was no difference between treatments when baculovirus suspension of 2 x 107 OB mL-1 was use and the mortality rates were higher than 91%. The mortality was higher when the larvae fed on cassava leaves treated with SfMNPV. Therefore, the food substrate increased the efficiency of SfMNPV, which promises the use of this virus in the management of S. frugiperda in cassava crops.A lagarta-do-cartucho, Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) é considerada a principal praga da cultura do milho (Zea mays L.) no Brasil e se alimenta de diversas outras espécies de plantas, inclusive mandioca (Manihot esculenta Crantz). O substrato alimentar influencia a eficiência de controle por baculovírus e não existem estudos sobre os efeitos da aplicação de baculovírus Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) em folhas de mandioca sobre a mortalidade de lagartas S. frugiperda. Objetivou-se avaliar a eficiência do isolado 6 de SfMNPV sobre lagartas S. frugiperda alimentadas com folhas de milho e mandioca. Os substratos alimentares foram tratados com três concentrações (2 x 105, 2 x 106 e 2 x 107 OB mL-1) de uma suspensão semipurificada e da formulação comercial (CartuchoVit®), ambos contendo o isolado 6 de SfMNPV e, em seguida foram oferecidos às lagartas de segundo instar de S. frugiperda. O vírus semipurificado foi mais virulento que o formulado comercial, independente do substrato alimentar fornecido aos insetos, quando aplicado nas concentrações de 2 x 105 e 2 x 106 OB mL-1. Porém, não houve diferença entre os respectivos tratamentos ao aplicar as suspensões virais com 2 x 107 OB mL-1, com mortalidades superiores a 91%. A mortalidade foi maior quando as lagartas se alimentaram de folhas de mandioca tratadas com SfMNPV. Portanto, o substrato alimentar aumentou a eficiência de SfMNPV o que torna promissora a utilização deste vírus no manejo de S. frugiperda em cultivos de mandioca
Kale density grown in an organic production system
Get PDFO objetivo deste trabalho foi avaliar a produtividade de folhas e indicadores econômicos do cultivo orgânico de couve manteiga em função da densidade de plantio. O experimento foi conduzido no Sítio Ecológico Seridó, em Rio Branco, AC. As mudas foram produzidas utilizando sementes, substrato e copos plásticos. O cultivo ocorreu sob casa de vegetação com 2 m de pé direito e 3,5 m de altura central coberta com filme aditivado transparente de 100 µ. O plantio foi realizado na densidade de 3,6; 4,2; 5,0; 6,3 e 8,3 plantas m-2, em linhas triplas espaçadas 0,40 m entre se e 0,50 m entre linhas tripas, nos espaçamentos de 0,30 m; 0,40 m; 0,50 m; 0,60 m e 0,70 m entre plantas na linha. Foram avaliados a massa fresca da folha, massa fresca de folhas por planta, número de maço, custos fixo, variável e total, custo total médio, receitas líquida e total, remuneração da mão de obra familiar, taxa de lucro, índice de rentabilidade, produção para cobertura total e relação benefício/custo. O adensamento de plantio reduziu a massa fresca da folha, a massa fresca de folhas por planta e aumentou a produtividade de folhas por unidade de área. A maior produtividade alcançada com o adensamento de plantio reduz linearmente o custo médio do maço de folhas, porém aumenta linearmente as receitas líquida e total, a remuneração da mão de obra familiar, a taxa de lucro, o índice de rentabilidade, a produtividade mínima para cobertura dos custos totais e os custos variáveis e total
Desiccation of potato haulm with contact herbicides and the final quality of tubers
Get PDFDesiccation of potato (Solanum tuberosum L.) haulms makes it possible to establish a physiological homogeneity of the haulms and anticipate the harvest of the tubers. This study aimed to evaluate the efficiency of different herbicides in the desiccation of potato haulms applied at the maturation phenological stages, and the effect of these treatments on the quality of tubers. An experiment was conducted in the field, in an area planted with Orchestra potatoes. This was a completely randomized experimental design with four repetitions. At the maturation phenological stages, the crop was applied with herbicides: diquat dibromide (400 g ha-1), paraquat dichloride (400 g ha-1), saflufenacil (70 g ha-1) and carfentrazone ethyl (60 g ha-1). Visual phytotoxicity assessments were performed at 3, 5, 10 and 15 days after application of treatments (DAT). At 15 DAT, tubers were harvested and evaluated for Brix (%), individual weight (g); diameter (cm); texture (kg/cm2) and starch. At 15 DAT, all herbicides resulted in desiccation close to 100%, however, saflufenacil showed the lowest speed of desiccation, since at 5 DAT the phytotoxicity was less than 86.25%. Texture, brix and diameter showed no statistical difference. The control and saflufenacil resulted in the lowest concentration of starch in the tubers and the highest concentration was obtained for carfentrazone-ethyl, paraquat and diquat. The treatments carfentrazone-ethyl, diquat dibromide and paraquat dichloride, were the most suitable for desiccation of potato haulms, providing fast desiccation speed and greater accumulation of starch in the tubers.A dessecação das ramas de batata (Solanum tuberosum L.) possibilita estabelecer uma homogeneidade fisiológica das ramas e antecipação da colheita dos tubérculos. O objetivo deste trabalho foi avaliar a eficiência de diferentes herbicidas na dessecação das ramas de batata aplicados no estádio fenológico de maturação, e o efeito desses tratamentos sobre a qualidade dos tubérculos. Foi realizado um experimento em campo, em área cultivada com batata da variedade Orchestra. O delineamento experimental foi inteiramente casualizado com quatro repetições. No estádio fenológico de maturação, foram aplicados os herbicidas: dibrometo de diquate (400 g ha-1), dicloreto de paraquate (400 g ha-1), saflufenacil (70 g ha-1) e carfentrazona-etílica (60 g ha-1). Avaliações visuais de fitotoxicidade foram realizadas aos 3, 5, 10 e 15 dias após a aplicação dos tratamentos (DAT). Aos 15 DAT foi realizada a colheita, e avaliações de brix (%), peso individual do tubérculo (g); diâmetro (cm); textura (kg/cm2) e amido dos tubérculos. Aos 15 DAT todos os herbicidas resultaram em dessecação próxima a 100%, no entanto, o saflufenacil apresentou a menor velocidade de dessecação, pois aos 5 DAT a fitotoxicidade foi inferior a 86,25%. As variáveis textura, brix e diâmetro não apresentaram diferença estatística. A testemunha e o saflufenacil, resultaram na menor concentração de amido nos tubérculos e a maior concentração foi obtida para carfentrazona-etílica, paraquat e diquat. Os tratamentos carfentrazona-etílica, dibrometo de diquate e dicloreto de paraquate, foram os mais adequados para dessecação das ramas de batata, proporcionando rápida velocidade de dessecação e maior acúmulo de amido nos tubérculos
Agricultural wastes incorporated to the substrate in the production of scarlet eggplant seedlings
Get PDFThe use of agricultural residues for seedlings production stands out as an effective sustainable alternative in the production of vegetables. This research aimed to evaluate the effect of increasing concentrations of wastes from the coffee beans drying process (moinha) on substrates composed of coconut fiber, eggshell and commercial substrate in the emergence and quality of scarlet eggplant seedlings. We carried out the experiment with five treatments, as the following: T0 – commercial substrate BioplantÒ; T1- 15% of moinha (MO) + 15% of coconut fiber (FC) + 5% of eggshells (CO) + 65% of commercial substrate (SC); T2 - 30% MO + 15% FC + 5% CO+ 50% SC; T3 - 45% MO + 15% FC + 5% CO + 35% SC; and T4 - 60% MO + 15% FC + 5% CO + 20% SC. We evaluated the emergency speed index, seed emergency, seedling height, stem diameter, shoot, root and total dry mass, Dickson’s Quality Index and the electrical conductivity of the substrates. The addition of moinha concentrations above 15% promotes an increase in electrical conductivity compared to the control and negatively affects the seedlings emergency. Among all treatments, 38% of moinha promotes an increase in the number of leaves, 15% of moinha results in higher plant height, stem diameter, and the highest dry mass accumulation. The alternative substrate containing 15% MO + 15% FC + 5% CO + 65% SC promotes a better development for scarlet eggplants seedlings, being an alternative to the exclusive use of the commercial substrate
Dynamic of blueberry buds dormancy in a region of low chill occurrence
Get PDFSeveral cultivars of blueberry were introduced in the colder regions in Brazil, but presented varied vegetative and reproductive growth, due to the heterogeneity of adaptation to the regional climate. The objective of this research was to determine the dormancy dynamics of blueberry buds grown in a region of low chill occurrence. Four methods of bud dormancy evaluation were used: biological test of single node cuttings, dormancy index, tetrazolium test and Tabuenca test. The dormancy of floral and vegetative buds of the cultivars Bluebelle, Climax, Delite and Powderblue of the Rabbiteye group was studied in collections every two weeks from April 26 to July 21. In the evaluated period there were only 76 h of temperatures below 7.2° C. The biological test and the dormancy index were viable methods for the dynamic evaluation of buds dormancy. The tetrazolium test was efficient to predict the exit of the endodormancy of floral and vegetative buds, but the Tabuenca test was efficient to predict the exit of floral buds dormancy only for the cultivars of less intense dormancy. The cultivars Bluebelle and Powderblue presented better adaptation to the conditions of low cold occurrence, with well defined installation and overcoming of the dormancy. The cv. Delite is more susceptible to budding heterogeneity and the cv. Climax is the least indicated to the region
Plant growth regulators for reducing pre-harvest fruit abscission in rainfed avocados
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Severe fruit drop events occurring after flowering and during early summer strongly limit rainfed avocado (Persea americana Mill.) production. This study aimed to evaluate the effect of late-spring and early-summer sprayings of plant growth regulators (PGRs) and monopotassium phosphite (PF), KH2PO3, on fruit abscission, yield and quality of non-irrigated ‘Quintal’ and ‘Margarida’ avocado trees. The following treatments were applied over two growing seasons: water; 25 mg L-1 of (2,4-dichlorophenoxy) acetic acid (2,4-D); and 45 mg L-1 of (E)-L-2-[2-(2-aminoethoxy)vinyl] glycine hydrochloride (AVG), separately applied as a single spraying in November; and three PF-sprayings, bi-weekly applied from mid-December to mid-January. The treatments did not affect fruit yield or quality of ‘Quintal’ avocados. Nevertheless, the PF sprayings significantly increased cumulative fruit yield of ‘Margarida’ trees (944 Kg tree¹, P = 0.0028). In both cultivars, the mean pre-harvest fruit drop in the studied biennium was not affected by the treatments, although AVG significantly reduced abscission of ‘Quintal’ avocados only in 2015 (3.88 fruits m-2, P = 0.0121), under non-stressful environmental conditions during fruit growth. In this cultivar, a single spraying, either with AVG or 2,4-D, significantly reduced fruit size and modified fruit shape. In the ‘Margarida’ cultivar, those treatments did not affect fruit shape, but a single 2,4-D spraying significantly increased diameter and length, by 2.7% and 1.9%, respectively. Large variability of the responses to the treatments among cultivars confirms that fruit abscission is a complex process regulated by several factors and demanding a multidisciplinary approach to develop efficient methods for its chemical manipulation
Tank mixture of pesticides for Tuta absoluta and Neoleucinodes elegantalis control in tomato crop
Get PDFThe use of pesticides in tank mixtures is important to reduce application costs and increase pest control, mainly. The objective of this study was to evaluate the influence of manganese foliar fertilizers on the effectiveness of the chlorantraniliprole (Chlt) to control tomato leaf miner and tomato fruit borer in tomato crop and to evaluate the possible effects of these mixtures on plant physiology. The experiment was conducted in a greenhouse, on randomized block design with eight treatments and four replications each. The treatments were: 1 – Chlt; 2 – Chlt + MnSO4; 3 – Chlt + Mn(NO3)2; 4- Chlt + Break-Thru (BTH); 5 - Chlt + MnSO4 + BTH; 6 – Chlt + Mn(NO3)2 + BTH; 7 – Chlt + MnSO4 + Mn(NO3)2 + BTH; 8 - Control. The physical chemical properties, physiological effects, pesticide efficacy and yield were evaluated. The results showed that the use of chlorantraniliprole in mixture with adjuvant and foliar fertilizers did not influence its efficacy against Tuta absoluta and Neoleucinodes elegantalis. Also, the mixture did not influence the chlorophyll content and all the nutrients content were in appropriate levels. We conclude that tank mixture with manganese foliar fertilizers do not have influence over the efficacy nor the physiological characteristics. The physical chemical evaluations changed according to each manganese salt add in the mixture.O uso de pesticidas em misturas de tanques é importante para reduzir os custos de aplicação e aumentar o controle de pragas, principalmente. O objetivo deste trabalho foi avaliar a influência de fertilizantes foliares a base de manganês sobre a eficácia do inseticida clorantraniliprol (Chlt) no controle da traça do tomateiro e da broca do tomateiro em cultivo de tomate em casa de vegetação e avaliar os possíveis efeitos dessas misturas na fisiologia da planta. O experimento foi conduzido em casa de vegetação, em delineamento de blocos ao acaso, com oito tratamentos e quatro repetições cada. Os tratamentos foram: 1 - Chlt; 2 - Chlt + MnSO4; 3 - Chlt + Mn (NO3) 2; 4- Chlt + Break-Thru (BTH); 5 - Chlt + MnSO4 + BTH; 6 - Chlt + Mn (NO3) 2 + BTH; 7 - Chlt + MnSO4 + Mn (NO3) 2 + BTH; 8 - controle. Foram avaliados as propriedades físico-químicas, os efeitos fisiológicos, a eficácia do pesticida e o rendimento. Os resultados mostraram que o uso do clorantraniliprol em mistura com fertilizantes foliares e adjuvantes não influenciou sua eficácia contra Tuta absoluta e Neoleucinodes elegantalis. Além disso, a mistura não influenciou o teor de clorofila e todos os nutrientes estavam em níveis adequados. Conclui-se que a mistura do tanque com fertilizantes foliares de manganês não influencia a eficácia e nem as características fisiológicas. As avaliações físico-químicas mudaram de acordo com a fonte de manganês adicionada na mistura
Hygroscopic behavior and morphological characteristics of okra powder obtained by convective drying
Get PDFOkra is a vegetable that stands out agronomically due to its fast growing cycle of high yield, in addition to considerable nutritional and commercial value. Due to its composition and because it is still consumed green, its shelf life in natural form is short. The objective of this work was to evaluate the hygroscopic, morphological and physical behavior of okra powders obtained in convective drying at different temperatures. The okra was cut into approximately 2 mm slices and dried in an oven with forced air circulation at temperatures of 50, 60, 70 and 80 ° C, with regular weighing until hygroscopic balance was reached. Then, the hygroscopic behavior of the powders was evaluated using water adsorption isotherms at a temperature of 25 ° C and mathematical models of GAB, Peleg, Oswin, Halsey and Henderson were adjusted to the experimental data. The powders were also submitted to morphological analysis by scanning electron microscopy (SEM) and X-ray diffraction analysis. The results showed that all models were well adjusted to the isotherms of okra powders, with emphasis on the GAB model, with determination coefficients (R2)> 0.99 and average percentage deviations (P) <5%; isotherms were classified as type II, typical of products with a large amount of sugar and solutes and with low adsorption. From the physical analysis, it was concluded that the powders presented morphologically irregular, asymmetrical structures with amorphous characteristics.O quiabo é uma hortaliça que se destaca agronomicamente por apresentar ciclo vegetativo rápido de alto rendimento, além de considerável valor nutritivo e comercial. Em razão da sua composição e de ser consumido ainda verde, a sua vida útil na forma in natura é curta. Objetivou-se neste trabalho avaliar o comportamento higroscópico, morfológico e físico dos pós do quiabo obtidos em secagem convectiva em diferentes temperaturas. Os quiabos foram cortados em fatias de aproximadamente 2 mm e submetidos à secagem em estufa com circulação forçada de ar nas temperaturas de 50, 60, 70 e 80 °C, realizando-se pesagens regulares até se atingir o equilíbrio higroscópico. Em seguida, avaliou-se o comportamento higroscópico dos pós por meio das isotermas de adsorção de água na temperatura de 25 °C e ajustou-se modelos matemáticos de GAB, Peleg, Oswin, Halsey e Henderson aos dados experimentais. Os pós foram submetidos também a análise morfológica por microscopia eletrônica de varredura (MEV) e análise por difração de Raios-X. Os resultados demonstraram que todos os modelos foram bem ajustados as isotermas dos pós de quiabo, com destaque para o modelo de GAB, com coeficientes de determinação (R2) > 0,99 e desvios percentuais médios (P) < 5%; as isotermas foram classificadas como do tipo II, típicas de produtos com grande quantidade de açúcar e solutos e com baixa adsorção. Da análise física, conclui-se que os pós apresentaram estruturas morfologicamente irregulares, assimétricas e com características amorfas
Post-harvesting longevity of bird of paradise (Strelitzia spp.) treated with carnauba wax
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Strelitzias are tropical plants that have shown great interest in the market and can be used in landscaping in tropical floral arrangements. Aiming to extend its postharvest life, the objective of the work was to evaluate different concentrations of the commercial product based on carnauba wax in the postharvest longevity of Strelitzia juncea and Strelitzia reginae leaves. The experiment was conducted in a completely randomized design with five treatments and six repetitions, with one leaf per repetition for each species. The concentrations used were: 0% (control), 2%, 20%, 40% and 100%. The loss of leaf mass (%) and the visual quality of the leaves were evaluated through the criterion of notes, in addition to making use of anatomical analyzes of the stomatal structures of the leaves through scanning microscopy. The loss of mass was reduced with the increase of the wax concentration, however, high doses provided increased loss. The use of carnauba wax proved efficient at concentrations of 20 and 40%, maintaining the commercial quality of the leaves of S. reginae and S. juncea until the 24th day, while in the control treatment, the leaves maintained a commercial pattern until the 16th for S. reginae and 18th day for S. juncea. The deposition of wax in the stomatal structures may have influenced the loss of mass of both species as observed by scanning microscopy.As Strelitzias são plantas tropicais que têm despontado grande interesse do mercado, podendo ser utilizadas no paisagismo em arranjos florais tropicais. Visando ampliar sua vida pós-colheita, o objetivo do trabalho foi avaliar diferentes concentrações do produto comercial a base de cera de carnaúba na longevidade pós-colheita de folhas de Strelitzia juncea e Strelitzia reginae. O experimento foi conduzido em delineamento inteiramente casualizado com cinco tratamentos e seis repetições, com uma folha por repetição para cada espécie. As concentrações utilizadas foram: 0% (controle), 2%, 20%, 40% e 100%. Avaliaram-se a perda de massa foliar (%) e a qualidade visual das folhas por meio do critério de notas, além de se fazer uso de análises anatômicas das estruturas estomáticas das folhas através de microscopia de varredura. A perda de massa foi reduzida com o aumento da concentração de cera, no entanto, altas doses proporcionaram aumento da perda. O uso de cera de carnaúba se mostrou eficiente nas concentrações de 20 e 40%, mantendo a qualidade comercial das folhas de S. reginae e S. juncea até o 24º dia, enquanto no tratamento controle, as folhas mantiveram padrão comercial até o 16° para S. reginae e 18° dia para S. juncea. A deposição de cera nas estruturas estomáticas pode ter influenciado na perda de massa de ambas as espécies conforme foi observado por meio da microscopia de varredura