Alexsander Seleguini

The 'Tahiti' acid lime (Citrus latifolia Tan.) is one of the main fruit trees produced in Brazil, but its triploid nature poses challenges for the genetic improvement of the crop. The aim of this study was to molecularly characterize selections of 'Tahiti' acid lime plants by quantifying DNA methylation and genetic differentiation using microsatellite markers, in order to support work on the conservation and genetic improvement of the crop. We used 12 plants considered to be mutants, previously selected for their distinct biometric characteristics. After extracting the genomic DNA, molecular analyses were carried out to measure the relative quantification of global methylation between the individuals. The experimental design used was completely randomized, with 12 treatments and 4 replications. Post-hoc analysis of the data was carried out using the Tukey test at 5%. Molecular analysis was then carried out using 12 pairs of microsatellite molecular markers. Differences were observed in the DNA methylation patterns between the treatments evaluated, especially treatments 3 and 9, which showed absorbance values of 0.621 and 0.266 nm, respectively. With regard to the analysis with microsatellite markers, it was possible to amplify 19 bands, but all were monomorphic, indicating that the different phenotypes observed may be due to alterations in the epigenome of these plants.

The purpose of this work is to present an alternative to the use of lamp and light diodes to increase production systems that lead to better natural energy use and better plant development. The species Euruca sativa L. was used, cultivated under a protected environment, and four treatments were taken (control; glossy white laminate; bright red laminate; aluminized thermoreflective screen). Our findings showed to reduce the efficiency of laminated reflective materials in increasing rucola production. The application of the red laminate with greater efficiency, positive results with the increase of fresh matter and number of leaves, increasing the energy efficiency of the plant. Furthermore, the better use of natural light can reduce production costs, since the application of artificial light generates an increase in fixed production costs. The purpose of this work is to present an alternative to the use of lamp and light diodes to increase production systems that lead to better natural energy use and better plant development. The species Euruca sativa L. was used, cultivated under a protected environment, and four treatments were taken (control; glossy white laminate; bright red laminate; aluminized thermoreflective screen). Our findings showed to reduce the efficiency of laminated reflective materials in increasing rucola production. The application of the red laminate with greater efficiency, positive results with the increase of fresh matter and number of leaves, increasing the energy efficiency of the plant. Furthermore, the better use of natural light can reduce production costs, since the application of artificial light generates an increase in fixed production costs.

The objective was to estimate the physiological and productive performance of potato genotypes in two organic cultivation systems. Two trials were conducted, being one in a protected and on in an open-field environment. A randomized complete block design with four replicates and five treatments (genotypes ‘Agata’, ‘Atlantic’, ‘BRS Ana’, ‘BRSIPR Bel’ and ‘BRS Clara’) was used. Physiological, productive characteristics and defects associated with tubers were obtained. The protected environment is the most appropriate to produce organic potatoes under the evaluated conditions. Genotypes ‘BRSIPR Bel’ and ‘BRS Ana’ exhibit a high productive potential in organic conditions.

Largamente utilizado em sistemas de produção de espécies produtoras de grãos em larga escala, o plantio direto tem sido adotado para a produção de hortaliças. No entanto, a elevada quantidade de possibilidades de combinações entre plantas de cobertura e sucessoras gera a demanda constante por estudos relacionados a essa temática. O objetivo do trabalho foi avaliar a utilização de diferentes espécies de gramíneas e leguminosas como possíveis culturas antecessoras ao plantio direto para a cultura da alface. Para tanto, foram avaliados seis tratamentos com plantas de cobertura: crotalária (Crotalaria juncea), feijão de guandu (Cajanus cajan), feijão-de-porco (Canavalia ensiformis), milheto (Pennisetum glaucum) e sorgo (Sorghum bicolor), além de um tratamento controle, com uso de vegetação espontânea. Verificou-se efeito positivo do cultivo da alface em sucessão ao sorgo, ao milheto e ao feijão-de-porco, enquanto que o seu cultivo em sucessão à crotalária e ao feijão guandu exibiu decréscimos da massa fresca, do número de folhas, do diâmetro da cabeça e da produtividade. Dessa forma, pode-se concluir que a formação de biomassa abundante sobre o solo, proporcionada pelas espécies de gramíneas P. glaucum e S. bicolor, melhora as condições de cultivo da alface em sistema de plantio direto, desde que realizado o correto manejo nutricional e hídrico da cultura. Em complemento, dentre as espécies leguminosas C. ensiformis proporciona o melhor desenvolvimento da cultura da alface, enquanto o cultivo de C. juncea deve ser evitado, a fim de não ocorrer perdas relativas no desenvolvimento da cultura de interesse.

Light-reflecting covers can help plant development in shaded environments, improving growing conditions in small residential spaces, encouraging the practice of small cultivations of food and ornamental species. Thus, the objective of this work was to evaluate the effect of reflective bench covers on the growth and development of different cultivars of basil, in pot and shaded environment. The treatments consisted of three reflective materials (aluminum thermal reflective mesh, shiny red and white coating on laminates), arranged on the cultivation benches, and two basil cultivars (green and purple). After 22 days under these environments, the number of leaves and nodes, stem diameter, plant height, relative chlorophyll content, fresh and dry masses of the aerial and roots parts were determined. The highest value of reflective photosynthetically active radiation was shown when using white laminate, followed by the red laminate and thermal reflective mesh. The green basil varieties showed higher values for number of leaves, stem diameter, plant height, fresh shoot weight and number of nodes, compared to the purple variety; however, in relation to the relative chlorophyll content, the purple variety was superior. The bright white and red laminate covers positively influence environmental conditions, increasing the reflectance of photosynthetically active radiation, and the development of basil plants in conditions of greater shading.

The northeastern region of Brazil is responsible for 95% of the country’s total melon production and 97% of total exported melons. This is mainly due to the edaphoclimatic conditions and the technological packages employed in the country for fertilization strategies. The aim of this study was to evaluate the effects of topdressing potassium fertilizers associated or not with sowing fertilization with Ekosil™ on the physicochemical traits of cantaloupes. The study was conducted in a randomized complete block design, with a 4×2 factorial arrangement (topdressing potassium nitrate [PN], potassium chloride [PC], potassium sulfate [PS] and Ekosil™ [EK], with or without sowing fertilization with Ekosil™). The evaluated traits in the fruits were: fresh mass (FM), soluble solids content (SS), titratable acidity (TA), SS/TA ratio (RA) and pigment contents (chlorophyll [CL] and carotenoids [CA]). No effect of treatments was observed on pH, CL, and CA (P>0.05). Interaction of sowing and topdressing fertilization was observed for the other variables (P0.05). Se observó la interacción de la fertilización en la siembra y la fertilización de cobertura para las otras variables (P<0.005). El PF fue mayor para CP y EK, con la aplicación de Ekosil™ en la siembra. Sin Ekosil™, SP, NP y EK dieron como resultado frutos más pesados. Los SS fueron mayores con SP al usar Ekosil™, y para SP y CP sin fertilización con Ekosil™ en la siembra. El CP y NP resultaron en mayor AT, y la RA fue mayor con SP. Bajo las condiciones edafoclimáticas de la región de Pontal do Triângulo Mineiro, la fertilización de cobertura con sulfato de potasio, sin fertilización con Ekosil™ en la siembra, da como resultado melones cantalupos más pesados y dulces.

The sector that ranges from cultivation to sale of ornamental species is highlighted in the agribusiness scenario, due to the frequent increase in demand for its products. This importance encourages the exploration of new technologies that allow the development of protocols for the multiplication of species of commercial interest. Thus, the objective of this study was to evaluate and validate the use of girdling, ethephon and the selection of degree of branch maturation as techniques for increasing the establishment of cuttings of Rhododendron simsii Planch. The treatments combining the three study factors were applied to the branches of the parent plants: two levels of girdling (with and without), two levels of application of ethephon at the concentration of 900 mg L-1 (with and without application) and two degrees of maturation (woody and herbaceous). It was found that the presence of branch girdling increased the rate of establishment of cuttings by 43.75%, while the joint use of two techniques, the application of ethephon and the selection of herbaceous cuttings, resulted in an establishment rate 56.25% higher than the average of other treatments. Thus, it can be concluded that both branch girdling and the application of ethephon combined with the use of herbaceous branches can be used as techniques for the greater establishment of cuttings of Rhododendron simsii Planch.

Lettuce cultivation is an activity of great economic importance; therefore, the use of techniques for better use of space and better-growing conditions should be evaluated. The objective of this study was to evaluate the development and yield of garden lettuce grown under different soil coverings and plant spacing. The study was conducted in an experimental area located at the School of Agronomy of the Federal University of Goiás, in the city of Goiânia, Goiás. The experiment was conducted in a randomized block design with subdivided plots in four replications. The plots consisted of three soil coverings (soil without cover, straw, and plastic cover) and the subplots in three planting spacing (PS1 = 25 x 20; PS2 = 25 x 25; PS3 = 25 x 30 cm), totaling nine treatments. The evaluations occurred when the plants presented their complete development, being evaluated: plant diameter, fresh head mass, stem mass, number of leaves, stem height; stem diameter; relative chlorophyll index; yield; and utilization, corresponding to the percentage of fresh marketable mass. It was found that the use of soil cover can favor the densification of lettuce cultivation. For cultivation on soil without cover or with the use of plastic as a cover, the cultivation spacing must be greater.

The effects of application of Azospirillum brasilense and thiamine on chlorophyll concentration and forage mass of Urochloa decumbens were evaluated in a small plot experiment conducted in Goiânia, Goiás, Brazil. The treatments were applications of: A. brasilense (concentration of 10 mL/L); thiamine at 2 concentrations: 50 and 100 mg/L; combinations of A. brasilense and thiamine at the 2 concentrations; and a Control treatment (untreated grass). At the first harvest there was a trend for applying A. brasilense, either alone or in combination with thiamine, to increase the concentrations of chlorophyll, but differences were not always significant at P0.05), while dry matter production of forage from applying A. brasilense alone and thiamine at 100 mg/L was greater (P<0.05) than that of Control and thiamine at 50 mg/L. Larger-scale and longer-term studies to validate these preliminary findings are needed.