Abstract in English:ABSTRACT Arrowroot is a plant originated in Latin America that has aroused interest in the food industry due to its high starch content, with differentiated characteristics and high commercial value. However, information on the management of arrowroot are scarce, precluding its commercial competition with other similar species, being necessary further studies with the crop. Thus, the objective of the present study was to characterize extracted starch from arrowroot grown under different agronomic management. Three agronomic factors were studied: planting systems (PS), forms of water management (WM) and planting density (PD). The experimental analyses were performed in a completely randomized design (CRD) with three replicates, being evaluated the extraction yield, percent composition, quantity of starch, pH, titratable acidity, swelling power, solubility and electron microscopy analysis. In general, the analyzed extracted starches deriving from different agronomic treatments have low crude fiber, besides typical characteristics of arrowroot extracted starch such as texture, color, shape and size of granules, without any other apparent particle than the starch itself, indicating extraction efficiency. However, the planting density may have contributed to influence some parameters of the chemical composition of the extracted starch, such as the content of starch, ash, ether extract, protein and carbohydrate fraction.
Abstract in English:ABSTRACT The variability of agronomic performance and of input use level of wheat commercial fields allows the identification of the factors with the greatest contribution to its economic performance. The objective of this work was to identify the main factors related to the variability of economic performance in wheat commercial fields in the Southern Region of Paraná State. The study was based on data from 65, 64 and 80 farms in 2013, 2014 and 2015, respectively. The variables evaluated were: costs of fertilizer, herbicide, insecticide, fungicide and seed; grain yield; and simplified gross margin (SGM). Data were subjected to Principal Components Analysis followed by Cluster Analysis. The variability of wheat economic performance was mainly related to grain yield, fertilizers cost and seed costs. Grain yield is one of the most important factors to determination of economic performance of wheat commercial fields in the studied region, and a greater investment in fertilizers and with seeds can decrease it. It must be considered that the cost reduction might be obtained with suitable management practices, and the contribution of items of cost analyzed to economic performance may be different in each cropping season probably due to variations of the cost profile and grain yield.
Abstract in English:ABSTRACT Avocado is currently an important crop in Colombia, given its growth in planted area and the increase in exports. The destination market of Colombian avocado is mainly international, and its quality is outstanding. However, the physical and chemical characteristics associated with the quality of the avocados produced are not currently well known in Colombia. The aim of this study was to evaluate the physical, chemical and nutritional parameters associated with the quality of Hass avocado in eight localities of the department of Antioquia based on descriptive statistics. Additionally, the quality was related to the localities through a multivariate analysis. As a result, quality at preharvest parameters of Hass avocados cultivated in Antioquia is similar or superior to that reported internationally based on physical and chemical variables. In addition, a relationship was established between the quality of fruits and the plots where these were cultivated, which allowed discriminating fruits by their region of origin. This work shows an approach to the determination of quality parameters in Hass avocado in Colombia and how they can be related to the characteristics of its productive system, which can lead to defining a product with added value.
Abstract in English:ABSTRACT Proper crop management is essential for preservation of medicinal plants of the Cerrado. There is no report of ex-situ cultivation of Allophylus edulis (vacum), which is used for its antimicrobial and antioxidant activities, in intercropping with Tropaeolum majus (nasturtium). Therefore, the aim of this study was to evaluate the effects of the intercropping with nasturtium and fertilization with chicken manure on yield of vacum. The experiment consisted of six treatments: monocrop vacum without chicken manure; monocrop vacum with hicken manure; monocrop nasturtium without chicken manure; monocrop nasturtium with chicken manure; vacum intercropped with nasturtium without chicken manure and vacum intercropped with nasturtium with chicken manure. The crop cycle of vacum took 540 days after transplanting and, during this period, nasturtium was cultivated in two cycles, in 2017 and 2018. Vacum showed greater height growth and production of fresh and dry masses of leaves in single cultivation with chicken manure fertilization. Nasturtium showed greater growth and flower production in monocrop cultivation with chicken manure fertiliazation, in the first cycle. The intercropping vacum with nasturtium was effective, showing Equivalent Area Ratio (EAR) of 1.16 and 1.18 without and with chicken manure, respectively.
Abstract in English:ABSTRACT Natural ventilation micropropagation systems differ from conventional systems by allowing gas exchange between the internal and external media of the culture flask. The objective of this work was to compare the conventional system of in vitro propagation of Eugenia dysenterica (Mart.) DC. with a natural ventilation system. For shooting, explants were inoculated into test tubes with conventional lids and natural ventilation lids (NV), and WPM medium supplemented with four concentrations levels of 6-benzilaminopurine (BAP). The position of explants in each plant was considered by identifying buds as more proximate to the root, or to the apex, or in an intermediate position. Plant growth in the natural ventilation system was superior to that in the conventional system, with a 448.53% increase in leaf number, 85.64% increase in chlorophyll a levels and 74.90% increase in chlorophyll b levels. Plants with intermediate buds exhibited better results. Foliar anatomical analysis revealed abnormalities in leaves grown in the conventional system such as “giant” stomata, which remain always open. Our results indicate that the use of natural ventilation improves the water loss regulation capacity in micropropagated E. dysenterica plants and may favor plants survival and growth after transference to the natural environment.
Abstract in English:ABSTRACT The objective of the study was to determine the antimicrobial activity antibiofilm and to identify the main components of the essential oil (EO) obtained from the leaves of Cymbopogon flexuosus. The antibacterial and antibiofilm activity was determined against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Salmonella Typhimurium ATCC 14028 and Listeria monocytogenes ATCC 19117. The effect of EO on biofilm was evaluated by quantifying viable cell number (CFU) and biomass by crystal violet (CV) analysis. The composition of the essential oils was determined by GC / FID and GC / MS. The results showed action against L. monocytogenes, S. aureus and S. Typhimurium with MIC and MBC values of 3.9 μL mL-1, thus showing satisfactory antimicrobial activity, given this was the lowest concentration tested. For the antibiofilm activity, a significant reduction (P < 0.05) was observed for S. typhimurium and S. aureus. Biofilm biomass significantly reduced only for S. aureus and P. aeruginosa. EO presented the geranial and neral isomers as major components.
Abstract in English:ABSTRACT Plants have organic components produced as secondary metabolites able to positively or negatively interfere on normal development of other species. The objective of this research was to determine the phytotoxic effect of aqueous leaf extract from two species Rubiaceae family: Tocoyena formosa and Rudgea viburnoides on the germination and initial development of lettuce (Lactuca sativa L). The extract was obtained from mixing 50 g of fresh leaf and 500 mL of distilled water. The experiment was arranged in completely randomized design for each specie, subjected to five extract concentrations: 0, 25, 50, 75 and 100%; and 4 repetitions of 50 seed each. The bioassays were performed in laboratory at controlled temperature and luminosity during seven days. Results showed that the aqueous extract of both species do not affected the germination and the percent of abnormal lettuce seedlings. R. viburnoides showed no pronounced difference in relation to shoot length and dry biomass; however, the root length was reduced by 85%. The extract of T. formosa at higher concentrations, drastically reduce the dry biomass and length of shoots and roots. Therefore, both species have phytotoxic effect on seedling growth of lettuce being the length root the most affected variable.
Abstract in English:ABSTRACT Efficient forest species can be indicated for reforesting environments, which present nutritional restriction. The objective of this study was to determine the nutrient stock in leaf biomass of the species of greatest importance value (IV) in a tropical dry forest fragment, as well as to evaluate the nutritional efficiency of these species as reforestation indicators. A phytosociological study of the woody species was carried out defining the ten species with the greatest IV. Three individuals of each species were selected and sampled, with 25 leaves being collected from the middle part of the crown of each individual. The N, P, K, Ca and Mg contents were determined in these leaves and the leaf biomass was estimated by an allometric equation, calculating the stock of these nutrients and the nutritional efficiency of the species. The Schinopsis brasiliensis and Mimosa tenuiflora species can be recommended in environments with restricted P availability, and Spondias tuberosa can additionally be indicated to populate areas with low levels of K and Mg in the soil. Differences in the nutritional efficiency of the species can be attributed to the differences in the absorption and translocation capacity, as well as the utilization of these nutrients.
Abstract in English:ABSTRACT One of the alternatives to achieve agriculture with sustainability and reduction in production costs, mainly with fertilizers, is the formation of straw from the previous crop and the use of genus Azospirillum bacteria. The objective of this study was to evaluate the agronomic characteristics and yield of soybean, cultivated in areas under straw of sorghum regrowth inoculated or not with diazotrophic bacteria, single or intercropped with Paiaguás grass under Integrated System of Agricultural Production, in Cerrado region. It was used a complete randomized block design, in a 2 x 2 x 2 factorial arrangement, with four replications, in two agricultural years: with the cultivation of dual-purpose and grain sorghum, single or intercropped with Paiaguás grass, with or without inoculating sorghum seeds with the bacterium Azospirillum brasilense. Soybean production and yield components were evaluated. Inoculation of grain or dual-purpose sorghum seeds with Azospirillum brasilense intercropped with Paiaguás grass, before soybean cultivation, increased the components of production and grain yield of soybean in succession.
Abstract in English:ABSTRACT Seeds of wild celery (Apium graveolens L.) from southern Brazil were surface disinfected with different solutions of sodium hypochlorite (5 and 10%) and acetic acid (0.5, 1, 2, 4%), and germination success and fungal infection were evaluated after 28 days of incubation at a constant temperature of 30 ºC and 20/30 ºC thermoperiod (12h:12h). Germination of wild celery was inhibited at the constant temperature (30 ºC). Vigorous total germination (90-100%), a faster germination velocity (1.8-2.5 germinated seeds per day) and moderate fungal infection (53.3-81.7%) of wild celery seeds were obtained with the sodium hypochlorite treatments (5-10% concentration) under the 20/30 ºC thermoperiod. The 4% treatment of acetic acid was very effective at preventing seed fungal infection (only 5% of the seeds) but it reduced the average total germination to 60%. Lower concentrations of acetic acid (0.5-2%) resulted in 100% fungal infection. In conclusion, seedlings of wild celery from southern Brazil can be effectively produced by disinfecting the seeds with 5 -10% sodium hypochlorite and incubation under a 20/30 ºC thermoperiod (12h:12h).