Repositório RCAAP

Studies regarding vegetal extracts and essential oils from native plants have demonstrated efficiency in controlling phytopathogens of fungitoxic action, hampering the development of phytopathogenic fungi. This study aims to determine the fungicide effect of vegetal extracts during the mycelial growth of the fungus Sclerotinia sclerotiorum (Lib.) de Bary. The experiment was conducted in the phytosanitary laboratory of the UEMS in the unit of Cassilândia-MS, Brazil. A completely randomized design was used with a factorial scheme 4 x 5, comprising leaves, bark, and branches of cinnamon and mint leaves in the concentrations of 0, 2.5, 5.0, 10, and 20%, with six repetitions per treatment. The evaluations were made 24, 48, and 96 hours after the transplant, obtaining the diametrically opposite means with a caliper to determine the measures. The results indicate a higher inhibitory efficiency against fungi development using extracts of mint leaves and cinnamon leaves and branches.

A consorciação de milho e Urochloa ruziziensis apresenta potencial para os sistemas de produção agrícola, permitindo a produção de grãos e biomassa remanescente. O estudo tem como objetivo avaliar a produtividade e a viabilidade econômica das modalidades de consórcio de milho e U. ruziziensis na região noroeste do Paraná. O experimento foi conduzido em Maringá-PR, em delineamento inteiramente casualizado com cinco tratamentos (milho solteiro; U. ruziziensis solteira; milho com U. ruziziensis na entre linha; milho com U. ruziziensis na mesma linha; milho com U. ruziziensis em linhas intercaladas) e quatro repetições. Foi analisado o desenvolvimento inicial e produtividade de grãos do milho, e produção de biomassa de milho e U. ruziziensis. Os dados foram submetidos a análise de variância e as médias comparadas pelo teste Tukey com significância de 5%. No desenvolvimento inicial das plantas de milho não houve diferença significativa em função da consorciação. U. ruziziensis em sistema consorciado apresentou redução na produção de biomassa. O cultivo em linhas intercaladas apresentou produtividade de grãos superior as demais modalidades de consorciação e semelhante ao cultivo de milho solteiro.

This study evaluates the influence of the four seasons and twelve months of the year on the micrometeorological variables of global solar radiation, air temperature, and relative air humidity in different protected environments for plant production. The protected environment types and the characteristics of the shade screen modify the indoor air temperature. This environment provides greater relative humidity. The global solar radiation percentages in the environments were: full sun (100%); black screen with 30% shading (47.3%); greenhouse with LDPE + 22-30% shading screen under the film (38.1%); aluminized screen with 35% shading (36.9%) and greenhouse with LDPE + 42-50% shading screen under the film (26.9%). The micrometeorological conditions of environments such as air temperature, relative air humidity, and global solar radiation in the seasons of year are similar to the behavior verified in the monthly test. Air temperatures and global solar radiation formed two distinct groups, with the spring and summer seasons being considered one group and autumn and winter another group. The summer and autumn periods showed the highest relative humidity compared to the winter and spring periods, with a low percentage of air humidity. Seasons in the study region are not as well defined as those in the northern hemisphere.

The drying and death of soursop seedlings (Annona muricata L.) were reported on Viveiro da Floresta in Rio Branco, state of Acre, Brazil, in March 2017. The seedlings were obtained from municipalities of Dona Euzébia, Minas Gerais state, and the seeds from Capixaba, Acre state, Brazil. Seedlings with dieback symptoms were taken to the Laboratories of Entomology and Phytopathology of Embrapa Acre and analyzed with a stereomicroscope. The thrips found were preserved in ethanol (70%), mounted on slides, and identified in the specialized literature. Moreover, the isolation of fungi from leaves and stems was performed, which were inserted on Petri dishes with a PDA medium. The insect was identified as Pseudophilothrips sp., and the fungi pertained to the genera Colletotrichum and Lasiodiplodia. The high infestation of thrips in soursop seedlings, related to the nutrition of insects, is probably associated with the entrance of opportunistic fungi. Thus, the fungi colonized already fragile plants by the initial attack of insects, causing the drying and death of seedlings.

Os sistemas integrados de produção lavoura-pecuária (SIPAs) em associação ao sistema de semeadura direta, sofrem ação do pisoteio animal ou do tráfego intenso de máquinas agrícolas, podendo resultar em alterações nas propriedades físicas do solo. O objetivo deste trabalho foi avaliar o efeito da adubação nitrogenada e manejos das forrageiras tropicais nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2017 e janeiro de 2020, em Marechal Cândido Rondon – PR, em blocos ao acaso, com parcelas sub-subdivididas com uma testemunha adicional e quatro repetições. As parcelas foram constituídas por duas espécies forrageiras consorciadas com o milho: Urochloa brizantha e Magathyrsus maximum, mais a testemunha adicional (milho solteiro). As subparcelas consistiram nos manejos das forrageiras: fenação e pastejo; e nas sub-subparcelas, a presença ou ausência de adubação nitrogenada. Foram determinadas: densidade do solo (Ds), porosidade total (Pt), macro (Ma) e microporosidade (Mi), além da resistência do solo à penetração (Rp). A utilização de nitrogênio (N) em cobertura nas forrageiras após os manejos, aumentou a quantidade de Ma na camada de 0-0,05 m para o primeiro ano. Os valores de Ds estão acima do limite considerado crítico para o desenvolvimento das plantas, porém, com tendência à redução. A adoção do SIPA, independente da espécie forrageira utilizada e manejo adotado, seja fenação ou pastejo, não comprometeu a qualidade física do solo, sendo assim, uma ótima alternativa para a diversificação da produção na propriedade.

O uso de fungicidas sintéticos é uma das estratégias de manejo de doenças mais utilizadas na agricultura, porém, busca-se manejos que sejam mais sustentáveis. Dessa forma, objetivou-se avaliar o potencial de óleos essenciais de Cedrela fissilis e Mentha spicata no controle, in vitro, do crescimento micelial do patógeno Corynespora cassiicola. O trabalho foi desenvolvido no Laboratório de Fitossanidade da Universidade Estadual do Mato Grosso do Sul (UEMS), Unidade Universitária de Cassilândia-MS. Os óleos essenciais, Cedro (Cedrela fissilis) e Hortelã (Mentha spicata) foram adquiridos comercialmente. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 2 categorias de óleos essenciais (hortelã e cedro) x 5 concentrações (0, 25, 50, 100 e 200 μL L-1). Os dados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Os dados quantitativos foram submetidos à análise de regressão. O efeito fungicida foi determinado através de medições do diâmetro das colônias (média de duas medidas diametralmente opostas), com auxílio de um paquímetro, a cada 72 horas até 216 horas. O óleo essencial de hortelã (M. Spicata) apresentou maior eficácia do que o óleo essencial de Cedro (Cedrela fissilis) na redução do crescimento de Corynespora cassiicola nos períodos de 72 e 144 horas in vitro.

In sowing operation, it is essential to control the factors that can affect the quality of seed and fertilizer deposition. These factors range from the correct choice of dosing mechanisms to machine regulation and operating speed control. The present research aimed to analyze the influence of sowing speed on the productive performance of the corn crop. The study was carried out at Fazenda São Geraldo, in the municipality of Boracéia, São Paulo. Four operating speeds 3, 5, 7 and 9 km h-1 were applied in a seeder, with a mechanical horizontal seed meter. The experimental design was carried out in strips. The results showed that sowing operational speed directly influences the final corn yield. There is a positive correlation between sowing speed and reduction in seedling emergence. The speed of 3.0 km h-1 showed the best results for seed deposition and yield. The speeds of 5, 7 and 9 km h-1 presented a reduction of 14.8, 42.5 and 67.2 bags per hectare.

The study aimed to evaluate the hydraulic conductivity using soil samples with undisturbed structure in the soil layers of 0-5, 5-10, 10-20, and 20-40 cm; 120 soil samples were collected. For the determination of hydraulic conductivity, the constant load permeameter was used. For geostatistical analysis, exploratory data analysis was performed using frequency histograms, determining the main measures of position and dispersion, verifying the trends for the construction of boxplot graphics, which allows the identification of discrepant points. The lowest and highest hydraulic conductivity values were found in the 20-40 cm and 0-5 cm soil layers, respectively; values commonly found in soils under forest conditions. Based on the results, we conclude when the soil sampling for analysis of hydraulic conductivity is random, the minimum distance between the points must be greater than 15.5 m.

Crop biomass plays an important role, especially in tropical and subtropical crops that adopt the no-tillage system, whose decomposition is related to material composition and environmental conditions. The objective of this work was to analyze the decomposition of straw remaining from autumn/winter crops in the development of soybean in succession in the Midwest region of Paraná. The experiment was conducted between 2019 and 2021 in a completely randomized design, with eight treatments (spontaneous, black oat, brachiaria, corn, wheat, oilseed radish, corn + brachiaria, and black oat + oilseed radish) and four replications. After autumn/winter cultivation, biomass samples were dried and placed in nylon bags, returning to the original plot during soybean sowing. The decomposition bags were collected in seven periods over 120 days, coinciding with the soybean cycle. The decomposition rate was analyzed by regression. The regression equations and the amount of biomass remaining from the autumn/winter seasons were determinate the half-file and the remaining mass on the soil surface at sowing and at 30, 60, 90, and 120 days after sowing. Biomass production and decomposition rate varied with the season, depending on environmental conditions. Wheat had the lowest decomposition rate with a half-life greater than 100 days. Intercropping crops reduce the decomposition rate.

There are many doubts about which straw-supplying species should be cultivated in a no-tillage system and which potassium doses are adequate for the Cerrado soils. Therefore, the current study aimed to evaluate the agronomic traits (plant height, first pod insertion height, and stem diameter); yield traits (number of pods per plant, number of grains per pod, and 100-grain weight), grain yield (kg ha-1) and potassium content in the leaves, in the production of soybean cultivated in different straws and potassium doses in two crop seasons under Cerrado conditions in the region of Ceres, Goiás, Brazil. Two types of straw (Brachiaria and millet) and four potassium doses were evaluated. A randomized complete block design arranged in a 2x2x4 factorial scheme with four repetitions was used. Two crop seasons (2011/2012 and 2012/2013), two types of straw (Millet and Brachiaria), and four potassium doses (0, 30, 60, and 90 kg ha-1 of K2O using KCl as source) were evaluated. Phosphate fertilization was performed using 400 kg ha-1 of simple superphosphate, and the cultivar used was P98Y12. The largest plant height values were obtained by applying 90 kg ha-1 of K2O. The Brachiaria straw promoted a grain yield increase associated with the potassium doses increment. The highest grain yield was 4,353.90 kg ha-1, achieved by applying 65 kg ha-1 of K2O using millet straw. The highest grain yield reached was at the rate of 90 kg ha-1 of K2O, resulting in 5,208 kg ha-1. The greatest K accumulation in the leaf is provided by Brachiaria straw.

Current study is emphasizing on the estimation of heterosis for different yield attributing traits and adaptability of tomato hybrids. It was performed in the research area of VCRP, HRI, NARC Islamabad during 2018-2019. Crossing was completed among six parents followed by line × tester. The analyzed data depicted significant differences (P ≤ 0.01) among all the characters.Due to desirable high negative heterotic values hybrids Peto-86 × Nagina and Riograndi × Roma were found suitable for breeding early maturing hybrids. For plant height maximum positive heterosis was observed in Riograndi × Nagina, for no. of cluster/plant in Naqeeb × Roma, for traits like flower cluster-1, fruit cluster-1, fruit length & width and single fruit weight in Naqeeb × Continental while for yield Riograndi × Continental showed maximum heterosis. Therefore among 9 tested hybrids Naqeeb × Continental was found to be highly preferable and recommended for utilization in different breeding programmes.

A produção de banana no Norte de Minas Gerais se baseia-se na variedade 'Prata-Anã', ocupando 90% de 10.000 ha cultivados com uma espécie. Essa variedade é suscetível às sigatokas amarela e negra, bem como ao mal do Panamá. Uma estratégia para superar esses problemas fitossanitários é desenvolver variedades resistentes, como quais são os critérios de um campo. O objetivo do presente trabalho foi determinar a produção e o diagnóstico nutricional para N e K de cultivares de bananeira Fhia 1, Fhia 2, Fhia 3, Pacovan Ken, Thap Maeo, Tropical, Caipira, ST406, PV4285 e PV4253, resistentes à Sigatoka amarela. Também se pesquisou com Prata anã, cultivar doença sensível. De acordo com os resultados, a bananeira Fhia 3 produziu cachos com maior massa, destacando-se entre as cultivares do grupo genômico tetraplóide, porém, para serem recomendados como variedade em cultivos comerciais é necessária avaliação complementar, principalmente a aceitabilidade de seus frutos pelos consumidores; a Fhia 2 também produziu cachos com redução de massa, sendo uma alternativa às bananas do subgrupo Cavendish pelo semelhante sabor; a Thap Maeo, entre as cultivares triplóides, atingiu elevada produção, sendo opção para cultivo em substituição à bananeira 'Maçã', na medida que é resistente à sigatokas, amarela e negra, e ao mal-do-Panamá, além de produzir frutos de sabor adequado; os teores de N e K estiveram na faixa de suficiência, indicando que nas condições ambientais as plantas foram suficientemente nutridas. a Fhia 2 também produziu cachos com redução de massa, sendo uma alternativa às bananas do subgrupo Cavendish pelo semelhante sabor; a Thap Maeo, entre as cultivares triplóides, atingiu elevada produção, sendo opção para cultivo em substituição à bananeira 'Maçã', na medida que é resistente à sigatokas, amarela e negra, e ao mal-do-Panamá, além de produzir frutos de sabor adequado; os teores de N e K estiveram na faixa de suficiência, indicando que nas condições ambientais as plantas foram suficientemente nutridas. a Fhia 2 também produziu cachos com redução de massa, sendo uma alternativa às bananas do subgrupo Cavendish pelo semelhante sabor; a Thap Maeo, entre as cultivares triplóides, atingiu elevada produção, sendo opção para cultivo em substituição à bananeira 'Maçã', na medida que é resistente à sigatokas, amarela e negra, e ao mal-do-Panamá, além de produzir frutos de sabor adequado; os teores de N e K estiveram na faixa de suficiência, indicando que nas condições ambientais as plantas foram suficientemente nutridas. além de produzir frutos de adequado sabor; os teores de N e K estiveram na faixa de suficiência, indicando que nas condições ambientais as plantas foram suficientemente nutridas. além de produzir frutos de adequado sabor; os teores de N e K estiveram na faixa de suficiência, indicando que nas condições ambientais as plantas foram suficientemente nutridas.

Energy cultures are emerging as viable renewable energy sources because they satisfy sustainability requirements. The present study involves a survey regarding the technological characteristics for sugarcane and sweet sorghum energy crops, in addition to their potential for bioethanol production. An exploratory survey was conducted regarding the agronomic and technological characteristics of cane and sorghum. Pre-inmates were produced with YPSAC 5% liquid medium, sterilized and 0.10 grams of yeasts FT858 and Pedra-2 were inoculated and incubated at 30 °C for 10 h at 250 rpm. After the production, the cells were recovered by centrifugation, at 105 rpm, resulting in a 10 mg mg-1 concentration of moist dough. This dough was subsequently inoculated in the fermentative medium consisting of a base of sorghum broth and cane without pH correction with a 22 °Brix. Ethanol was analysed by gas chromatography and amino acids by high-efficiency liquid chromatography. Sorghum broth presented a greater availability of serine, arginine, alanine, threonine, and tryptophan amino acids. Yeast hers presented fermentative efficiency for both substrates, but the largest ethanol production occurred in sorghum broth. The results demonstrated that sugar sorghum may be used for energy purposes.

Convencionalmente a semeadura da soja é realizada distribuindo as sementes de forma individualizada e equidistante ao longo do sulco de semeadura. uma possível alternativa é a dosagem e distribuição agrupada de sementes, apenas rearranjando-as. Sendo assim, o objetivo do trabalho foi avaliar as características agronômicas da soja semeada com disco dosador de sementes convencional e agrupado sob diferentes velocidades operacionais. O delineamento experimental adotado foi o inteiramente casualizado em esquema fatorial 2 x 3, sendo dois arranjos de semeadura, agrupado e convencional, e três velocidades de semeadura 4,5; 5,2 e 6 km h-1, com quatro repetições cada. Os resultados evidenciam incremento produtivo entre 20,7% e 39,9% para o arranjo agrupado nas velocidades de 5,2 e 4,5 km h-1, respectivamente. A maior velocidade de semeadura limita o agrupamento de sementes para o arranjo agrupado. 

Gibberellin is a plant hormone capable of enhancing the productivity of plant’s productivity rants, due to its action in plant physiology, mainly in fruit formation. In this sense, this study aimed to evaluate gibberellic acid levels and application times on the growth and quality of ‘Pérola’ pineapple. The experiment was conducted under field conditions in the municipality of Pedras de Fogo, state of Paraíba, Brazil. The treatments consisted of five levels of gibberellic acid (0.0, 1.5, 3.0, 6.0, and 12.0 mg/plant), distributed in a randomized block experimental design, with four repetitions, in which three applications were made at 50, 80, and 110 days after flower induction. The soluble solids content, fruit height, fruit diameter, and weight were evaluated. The period of application and the levels of gibberellic acid altered the responses for the variables analyzed. The level of 7.5 mg/plant of gibberellic acid promoted an increase in the weight and diameter of the fruit. The application at 110 days after floral induction induced an increase in fruit weight and a greater concentration of sugar in the fruit. Further studies on the application of gibberellic acid and periods of application in different soil and climatic conditions should be carried out to determine more consistent results with this crop.

teste

Forage species, mainly those from the Urochloa genus, have been an essential alternative for utilization in no-tillage systems (NTS) due to their high biomass production and C/N ratio. However, for adequate development of the subsequent crops, the desiccation of forage plants must be efficient using herbicides. This study aimed to investigate the death kinetics of forage species from the Urochloa genus submitted to different levels of glyphosate. The treatments consisted of four forage species (Urochloa brizantha cv. BRS Paiaguás, U. ruziziensis, U. brizantha cv. Piatã, and U. spp. cv. Ipyporã) submitted to four doses of glyphosate (250; 500; 1,000 and 2,000 g a.e. ha-1). Visual assessments about the phytotoxic effect were made on 7, 14, 21, and 28 days after application (DAA). The evaluated species have different sensitivities to glyphosate and U. brizantha cv. BRS Paiaguás and U. ruziziensis are the most susceptible to this herbicide. The doses of herbicide affect the death kinetics of these forage species. Higher doses of glyphosate reduce the desiccation time of these forage plants.

Agricultural productivity in irrigated areas depends on several factors, including the design and maintenance of irrigation systems. Excessive or insufficient applications of water affect plant growth and development, hence agricultural productivity. For this reason, the evaluation of the irrigation system is essential to avoid water loss during application. This study aimed to evaluate the efficiency and uniformity of a subsurface drip irrigation system in sugarcane crops in an area of the company Usina Coruripe, Alagoas, Brazil. For data collection, the flow rates were obtained in four points along the lateral line, in the first dripper, in the drippers located at 1/3 and 2/3 of the lateral line length, and in the last dripper of each operational unit of the irrigation project. In each row, four emitters were evaluated, totalizing 16 emitters, using a chronometer, collectors, and a measuring cylinder for data collection. In these emitters, the volume of water was collected for 3 minutes, with three repetitions. Christiansen's uniformity coefficient, distribution uniformity coefficient, statistical uniformity coefficient, Hart's uniformity coefficient, and application efficiency were estimated. The irrigation system was considered excellent for distribution uniformity. The application efficiency was classified as acceptable, with an average value of 88.9%. However, despite the application efficiency being classified as acceptable, periodic evaluations of the system are recommended.

Species from the genus Campomanesia have been studied due to their biological activity and low toxicity. However, studies on the fruit peel of these species are scarce. In this context, the effects of ethanol extract from the fruit peel of Campomanesia sessiliflora (O. Berg) Mattos (CS) and Campomanesia guazumifolia (Cambess) O. Berg (CG) were evaluated concerning the effect on germination and meristem cells of roots of Allium cepa. The CG ethanolic extract showed flavonoid compounds higher than CS ethanolic extract. The CS extract showed no antioxidant activity. CS showed greater antiproliferative activity with reduced root size in A. cepa seeds. The two extracts did not induce mutagenicity and cell death at the studied concentration of 1 mg mL-1. Keywords: Germination, Allelopathy, Ethanolic extract.

Este trabalho apresenta parte de uma pesquisa quantitativa cujo principal objetivo foi avaliar a satisfação no casamento de homens e mulheres que optaram por relacionamentos de duplo trabalho. Participaram do estudo 222 homens e 222 mulheres casados/as, funcionários/as em diversas instituições públicas de Brasília - DF. A maior concentração de respondentes de ambos os sexos está na faixa etária entre 31 a 40 anos. Os participantes responderam a um questionário demográfico e à Escala de Ajustamento Diádico - DAS. Os resultados mostraram que a maioria dos participantes está satisfeita com seus relacionamentos, sendo que as mulheres apresentaram média de satisfação inferior à dos homens. Quanto à percepção do futuro do relacionamento, ficou evidente o comprometimento de homens e mulheres em investirem na manutenção do casamento. Os resultados questionam a idéia vigente de falência do casamento e da família e apontam para uma transformação das relações.