Resumo em Inglês:

ABSTRACT The aim of this study was to model the decendial and hourly variability of meteorological variables, namely air temperature, relative air humidity and wind speed, in the Tangará da Serra region, Mato Grosso, Brazil, to determine the best schedules for fungicide applications to soybean crops. Hourly weather data between 2004 and 2017 from the Tangará da Serra municipality’s automatic station were made available by Brazil’s National Meterological Institute (Instituto Nacional de Meteorologia, INMET). Decendial variability (ten days 01 to 36) and hourly variability were analyzed for ten days that concentrated fungicide soybean crop applications, namely ten days 34, 35, 36 and 01. The following parameters were adopted as suitable fungicide application climate: wind speed ≥ 0.83 ≤ 2.77 m s-1, relative air humidity ≥ 50% and air temperature ≤ 30 °C. Relative humidity was not a limiting factor for application on ten days 34, 35, 36 and 01. Due to hourly maximum temperatures, suitable application conditions are less than 10% at 1:00 PM. The most frequent suitable weather conditions schedules are concentrated between 5:00 AM and 7:00 AM, and at night, from 7:00 PM.

Resumo em Inglês:

ABSTRACT Irrigation can provide significant agronomic and financial returns on agricultural activity. The maximization of the benefits obtained from irrigation depends, among other factors, on the water use efficiency, which is intrinsically related to application uniformity. For the sprinkler method, the irrigation uniformity assessment is based on results of labor-intensive field tests in which the two-dimensional water distribution pattern is measured in a grid of catch cans. The aim of this study was to evaluate a simplified methodology for determining the irrigation uniformity using water depth distribution data of a single sprinkler head in operation, positioned at the intersection of two diagonal alignments containing regularly spaced catch cans. Three methods to simulate the spatial water distribution on the alignments were evaluated: linear interpolation (LI), cubic spline (SC) and second-degree polynomial regression (PR). Each of these methods were associated with a procedure to calculate the two-dimensional spatial water distribution. The adequacy of the LI and SC modeling methods was verified by using the Wilcoxon-Mann-Whitney test (p-value < 0.05) applied to the data of the field tests. Mean values of the coefficient of efficiency equals to 0.771 and 0.785 were obtained for the LI and SC methods, respectively. The PR method underperformed the others.

Resumo em Inglês:

ABSTRACT The use of organic waste for the production of plant substrates is an important environmental and economic alternative. In this perspective, we performed a work in a greenhouse, with the aim of evaluating the effect of substrates from organic waste during growth, gas exchange and accumulation of mineral elements in ‘Sunrise Solo’ papaya tree seedlings. The experimental design adopted was completely randomized, with four treatments and five repetitions, with six plants in each repetition. The treatments consisted of four types of substrates, three from the composting of sewage sludge, green coconut shell and carnaubeira palm butt, and one was the Turfa Fértil® commercial. We evaluated biometric and physiological variables and accumulation of nutrients and heavy metals in papaya seedlings. The green coconut shell and carnaubeira palm butt substrates promoted superior results for growth, dry biomass, gas exchange and accumulation of nutrients, whereas the commercial substrate and sewage sludge produced seedlings of inferior quality considering all the analyzed variables.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the development of pitaya cuttings in different substrates under different frequencies of irrigation. The experiment was conducted from January to May 2017 in a greenhouse at Universidade Federal Rural da Amazônia, Capitao Poço, Pará, Brazil. A completely randomized 3 × 7 factorial design with four replicates was used. Pitaya plants were grown from cuttings in three types of substrates (S1: potting soil; S2: potting soil + cattle manure + wood shavings; and S3: washed sand) under seven irrigation frequencies (24, 48, 72, 96, 120, 144, and 168 h). There was interaction between treatments for root dry matter production, root length variables, the other variables showed no interaction between treatments. The greater development of new and vigorous tissues of the aerial part, the substrates with composition black earth and black earth + manure + sawdust are indicated, and the adoption of the irrigation frequency of 72 h or 96 h. The use of substrate based on black earth + manure + sawdust, allows savings in the rational use of water and energy with the application of the 96 h irrigation frequencies, maintaining satisfactory levels of development to the plant. The washed sand substrate can be used for propagation when this material is abundant, however, greater attention should be paid to the supply of water and nutrients to the plant.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the development, yield and its components of soybean sown in hill drop method with variation in hole spacing, compared to the conventional sowing method in lines. The experiment was conducted in a randomized block design, with six treatments and four replications, using the variety M7739 RR IPRO with four plans per hole. The treatments consisted of population variation from 50 to 150% of the recommended one, obtained by the holes spacing alteration and a control sowed in lines with the recommended population. The control was compared to the other treatments using the Dunnett test and the hole spacing effect was evaluated by regression. The cultivar 7739 RR IPRO responds to hill drop sowing, obtaining even in lower populations, yields similar to the conventional sowing in lines. The highest yields in the hill drop sowing method are obtained in the higher populations, with a linear decrease in yield with an increase in hole spacing. Increasing hole spacing increases the number of pods and branches and reduces leaf cover, light interceptcion, plant height and first pod height.

Resumo em Inglês:

ABSTRACT This study aimed to fit mathematical models to whey foam drying processes in different air temperature conditions, to determine the effective diffusion coefficient and to obtain the activation energy. For foam formation, 5.0% Emustab® was added to the serum in mass and subjected to stirring in a domestic shaker for 15 min. After, it was spread onto trays to form a thin layer of about 1 cm in which the drying conditions were: 40, 45, 50, 55 and 60 °C, 5.6 m s-1 and 60%. The Logarithm and Midilli models describe the kinetics of serum foam drying; the effective diffusion coefficient increased with the elevation of drying temperature and activation energy of 50.84 kJ mol-1.

Resumo em Inglês:

ABSTRACT There is currently a lack of information regarding the performance of cover crops grown in the Coastal Tablelands region in the North of the Brazilian state of Espírito Santo, where zero tillage is increasingly being adopted. The objective of this study was to evaluate the agronomic performance of six cover crops (ruzi grass, jack bean, and the millets ADR 300, ADR 500, ADRf 6010, and BRS 1501) under two irrigation regimes. A field experiment setup was based on randomized blocks with split plots and four repetitions. Shoot dry matter content, plant height, leaf area, chlorophyll fluorescence, and root growth of the cover crops were evaluated. The irrigation regime influences the agronomic performance of most of the cover crops, with the exception of jack bean and ADRf 6010 millet, which were tolerant to water deficiency, based on our evaluations of the variables shoot dry matter, plant height, and leaf area. In terms of biomass production, ADRf 6010 millet is the most suitable crop for use in conservation systems under conditions of water stress in this region.

Resumo em Inglês:

ABSTRACT The present study aimed to evaluate productive characteristics and the physical, chemical and sensory quality of juices elaborated from different genotypes of the ‘Bordô’ cv. produced in the Vale do Rio Peixe-SC region, in 2016/17. The 11 clones evaluated were identified as: G03, G07, G08, G10, G12, G13, G15, G16, G17, G18 and G19. At harvest, fruit production and quality were evaluated. The mean productivity of the 11 tested genotypes was 31.2 t ha-1, with a production of 18.7 kg/plant. Genotypes G13, G16, G19 and G08 showed higher productivity in t ha-1 and kg/plant. G10 had the highest acidity. Genotypes G18 and G19 showed lower color intensity and phenolic compounds. Sensorially, genotypes G19 and G16 received lower scores for color, pleasant aroma and overall impression aspects. The 11 ‘Bordô’ genotypes evaluated showed high productivity and favorable physical, chemical and sensory characteristics for the industrialization of juices in the Vale do Rio do Peixe-SC region, with the exception of the juices of genotypes G18 and G19, which showed little color, something that may end up mischaracterizing the 'Bordô' juices.

Resumo em Inglês:

ABSTRACT Understanding the kinetics of Zn absorption by roots and its effect on morphology of this organ is relevant for improving crop management, but still poorly studied for common beans. Therefore, an experiment was conducted in a hydroponic system with five initial concentrations of Zn (CZnI): 0.0; 1.0; 4.0; 16.0 and 48.0 µmol L-1. The experiment was installed with plants at V3 stage of development and aliquots of the solution collected over 24 h. The maximum absorption rate (Vmax), Michaelis-Menten constant (Km) and the absorption power (α) increased as a function of CZnI. The minimum concentration of Zn estimated for its absorption (Cmin) was at 0.0028 mg L-1. The influx of Zn (Imax) was higher in higher CZnI, 16,0 µmol L-1. Root length, root volume, root Zn content and Zn absorption efficiency increased with the increase of CZnI. Therefore, the increase of CZnI positively influenced kinetic parameters of root Zn absorption and common bean root morphology, characteristics that favor Zn absorption by roots and improves overall plant nutrition, favoring agronomical biofortification practices for Zn and other nutrients.

Resumo em Inglês:

ABSTRACT Grain yield is a constant concern in soybean breeding programs for being highly influenced by the environment. This trait can be significantly affected by the sowing times. Thus, for the correct cultivar recommendation, methods of stability and adaptability analysis are used to verify the genotype x environment interaction at different sowing times. In this study, ten soybean cultivars were evaluated in 2016/2017 and 2017/2018 seasons, at different sowing times. Each experiment was carried out in a randomized block design with three replications. The methods of Eberhart & Russel and Lin & Binns were used for cultivars recommendation for general, favorable, and unfavorable environments. Cultivars CS2728, BONUS, and BRS1074 show high yield and predictability and therefore are the most suitable for the region of Chapadão do Sul.

Resumo em Inglês:

ABSTRACT The present study aimed to estimate genetic parameters of 20 common bean genotypes, commercial and regional bean on weed interference. The agronomic characters analyzed were: average stem diameter (ASD); average plant length (APL); number of pods per pot (NPP); number of locules per pod (NLP); number of grains per pod (NGP); percentage of empty locules (% EL); total grains per pot (TGP); total grain weight per pot (TGW) and average grain weight (AGW). High heritability values were found for most of the characters studied, except for NGP and EL; in addition to great genetic variability among genotypes. Therefore, for most of the characteristics of agronomic interest studied, simple selection methods can be applied with great potential to identify superior genotypes and consequent genetic progress in common bean breeding.

Resumo em Inglês:

ABSTRACT The objective of this work was to assess the breeding influences in different agronomic and physiological traits in Brazilian soybean cultivars, released between 1965 and 2011, to identify traits associated with modern cultivars. A total of 29 cultivars were evaluated in two locations in the 2016/17 crop season. Genotype selection based on agronomic and physiological traits was determined using GYT (Grain Yield*Trait) methodology, which uses the Superiority Index to rank genotypes by mean of all traits. Grain Yield is combined with other target traits and shows the strengths and weaknesses of each genotype. Soybean breeding improved desirable traits during the 46 years of evaluation. Superiority index can be a powerful tool for breeders to obtain high genetic gains in the future. The cultivars DMario 58i, TMG 7161RR and TMG 7262 RR stand out as the best cultivars but present different sets of desirable traits. The traits grain yield, harvest index, number of pods per plant, reproductive-vegetative ratio, photosynthetic rate and transpiration rate are core traits which can be evaluated in soybean breeding programs.

Resumo em Inglês:

ABSTRACT The seed coating technique adds value to the seeds. This technique allows changing the seed size and shape, facilitating sowing, and also the application of essential nutrients to the good development of the plant in the post-germination phases. Therefore, the objective of this work was to evaluate the physical and physiological characteristics of Stylosanthes capitata/macrocephala coated with different materials. For the coating procedure, a N10 Newpack bench seed coating machine was used. The experimental design was completely randomized, with four replications and 50 seeds per plot distributed in 10 treatments. The different materials and their respective mixtures significantly altered the physical characteristics, the weight of a thousand seeds (WTS), water content (SWC), maximum diameter (DMA), and minimum diameter (DMI) of the seeds. Among the different materials, the sand coated seeds had the highest germination percentage (%G), germination velocity index (GSI), and first germination count (FGC). The maintenance of physiological attributes was observed in sand coated seeds (0.25 mm). Therefore, it is an alternative application of nutrients via seeds, due to the inert character of the sand. The mixing of the materials used in this work is not recommended.

Resumo em Inglês:

ABSTRACT Water stress during wheat seed germination and seedling establishment for affect the percentage and speed of germination. Silicon (Si) is related to plant tolerance to different types of stress, then the application of this nutrient in the mother plant during seed production could contribute to the improvement of the seed quality and, consequently, its tolerance to stress. The aim was to evaluate the effect of foliar application of silicon on the tolerance of wheat seeds, produced under different irrigation levels, to water stress during germination and initial seedling growth. Wheat seeds were produced under three irrigation depths (0, 50 and 100% of the total required irrigation) applied after the anthesis. The silicon was supplied in two doses by foliar application (0 and 5 mM of Si). The germination and seedling growth were performed under water stress induced by PEG 6000 at the -0.2; -0.4; -0.6 MPa osmotic potentials. In addition, in the control only distilled water was used. The reduction of the osmotic potential reduced seed germination, germination speed and seedling growth. Irrigation depths, as well as foliar application of Si, during seed production did not influence the physiological quality and tolerance of seeds to water stress during germination.

Resumo em Inglês:

ABSTRACT The first record of Conotelus luteicornis Erichson (Coleoptera: Nitidulidae) was made in a commercial passion fruit vine planting in the municipality of Senador Guiomard, Acre state, Brazil. The insects were found inside the flowers where larvae and adults feed, causing early abortion and, consequently, losses in production. Therefore, the first record of this species is made in the Brazilian Amazon. Researches related to damage level, population dynamics, prospecting for natural enemies, and control methods are strongly recommended since this nitidulid is an insect with high harmful potential to the passion fruit vine culture in the Amazon region.