Doutorado em Agronomia (EA)

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    Fertilização nitrogenada como ferramenta para mitigação de efeitos do déficit de radiação solar no arroz irrigado
    (Universidade Federal de Goiás, 2023-09-06) Carvalho, Renata de Castro Marques; Moraes, Moemy Gomes de;; Heinemann, Alexandre Bryan;; Heinemann, Alexandre Bryan; Stone, Luís Fernando; Santos, Marcos Paulo dos; Silva, Rodrigo de Souza; Silva, Elaine Fernanda da
    Rice is part of the routine diet of the Brazilian population. Worldwide, it is considered one of the species with the greatest potential for combating hunger. Nitrogen is the nutrient most required by the rice crop. Solar radiation is one of the elements of the climate that most affects crop productivity. In Brazil, rice is grown in different regions, whose locations have a different supply of solar radiation throughout the cycle. This is one of the factors that explains the differences in productivity between regions. Some studies have shown that the supply of nitrogen as a top dressing minimizes the damage caused by solar radiation deficit in irrigated rice. In view of the above, the aim of this study was to determine the impact of the solar radiation deficit on two cultivars of irrigated rice and to investigate whether the supply of nitrogen minimizes the effects caused by this deficit. Two field trials were conducted for the 2019/2020 and 2020/2021 harvests. The work was carried out at the Palmital Farm experimental station, belonging to Embrapa Rice & Beans, in the municipality of Goianira-Goiás. The experimental design was randomized blocks, with four replications. The treatments were arranged in a subdivided plot design, with shading as the main plot, the nitrogen dose as the subplot and the cultivars as the sub-sub-plots. The cultivars studied were BRS Catiana and IRGA 424 RI. The nitrogen source used was urea, at doses of 50 kg ha-1 of N (applied just once, at the V2 stage) and 180 kg ha-1 of N (spread over three seasons, V2; V3 and V6, with the respective doses of 50; 50 and 80 kg ha-1 of N). The light-restricted plots were covered with a black propylene screen with an attenuation capacity of 30% of global solar radiation, which was installed at the start of flowering (R4) and remained in place until physiological maturity (R9). Fifteen days after the shading was installed, the plants' gas exchange was assessed using an infrared gas analyzer. At the same time, plant samples were taken for analysis of non-structural carbohydrates (NSC) and total nitrogen content. At harvest time, a 1.0 m row was sampled for analysis of yield components. Yield was obtained by harvesting 10 m of the row. Whole grain yield was assessed by processing a 100 gram sample from each experimental plot. The data was submitted to analysis of variance and the means were compared using the Tukey test (p<0,05). Shading reduced the concentration of non-structural carbohydrates in the leaf and stem of the cultivars in the shaded condition. The nitrogen content in the plant was reduced under conditions of light restriction. Gas exchange (net photosynthesis, stomatal conductance, internal CO2 concentration and transpiration) was affected by the availability of solar radiation. Under shaded conditions, there was a lower yield of whole grains. Increased nitrogen application allowed for a recovery in gas exchange, non-structural carbohydrates, nitrogen content in the plant, productivity and whole grain yield, under conditions of limited solar radiation. The IRGA 424 RI cultivar had a greater ability to adjust in the shaded condition compared to BRS Catiana, which implied higher productivity in this condition. In the unshaded condition and at the highest dose of N (180 kg ha-1), the BRS Catiana cultivar showed higher productivity than IRGA 424 RI. Applying nitrogen as a top dressing is a management strategy that can be applied to minimize the impact of solar radiation deficit on irrigated rice crops.
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    Fenologia de plantas e curva de maturação de frutos de caquizeiro
    (Universidade Federal de Goiás, 2020-05-01) Nascimento, Lucas Marquezan; Cunha Júnior, Luis Carlos;; Campos, André José de;; Seleguini, Alexsander;; Souza, Elí Regina Barboza de; Campos, Luiz Fernandes Cardoso; Vendruscolo, Eduardo Pradi; Camilo, Yanuzi Mara Vargas; Seleguini, Alexsander
    Climatic changes tend to cause changes in the phenological behavior of plants, directly influencing the development and changing the duration of the cycle. Such variations will influence the management, growth, seasonality of the plants and their fruits, as well as their maturation and quality. The objective was to evaluate the phenological behavior and fruit development of three common persimmon cultivars (Rama Forte, Giombo and Pomelo) conducted in the Midwest of Brazil. The plants were evaluated during four subsequent cycles, from August 2014 to June 2018. For the studies that involved the phenology of the plants, the following phenophases were counted, in days after the production pruning: swollen bud, green tip, sprouting , flowering, fruiting, fruits with 50% of the final size, fruits with 70% of the final size, fruits with 90% of the final size, beginning of the harvest and end of the harvest. For thermal sum the thermal sum or degrees-day (GD) was considered for the culture to complete each phenological phase. The number of accumulated cold hours (NHF) was also quantified. For the ripening curve, in 2018, 120 fruits were marked on six plants in the orchard. Weekly, two months after pruning and application of hydrogenated cyanamide (WAC), the transversal (DT) and longitudinal diameter of the fruit (DL) in the field were evaluated. From the 18th to the 31st week after the application of hydrogenated cyanamide, nine fruits were analyzed weekly being measured the color of the pulp and skin, external and pulp firmness (FIR), fresh mass, soluble solids content (SS), titratable acidity (AT), pH and Maturation Index. In hot years and with late pruning, plants sprouted more quickly. ‘Pomelo’ has adapted better to the local climate. The interval between sprouting and flowering in tropical conditions was shorter than that observed by other authors in milder climates. Annual climatic variations caused differences in the growth rates of the transverse diameter of the fruits. ‘Pomelo’, ‘Giombo’ and ‘Rama Forte’ reached the point of harvest with less thermal need compared to other published works. ‘Rama Forte’ and ‘Giombo’ did not show a pattern of thermal demand between the years. At least 400 hours below 14 ° C met the demand in cold hours of the persimmon tree. Fruit growth was faster until the 14th WAC. Between the 15th and the 20th WAC there was a reduction in the growth rate, and after the 22nd WAC the fruits started to have a more expressive growth. ‘Pomelo’ had bigger and heavier fruits. The epidermis of the fruits changed from green when immature to intense red when ripe. In three weeks, the external FIR went from 81 N to 5 N. The peak in the SS content of the fruits of ‘Pomelo’ and ‘Rama Forte’ was at the 26th WAC, and ‘Giombo’ at the 29th SAC. Under tropical savanna conditions, it is recommended that the best time to harvest the fruits of the cultivars is about three weeks before full maturity.
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    Evapotranspiração das culturas do milho e feijão no bioma Cerrado utilizando sensoriamento remoto por drones e satélites
    (Universidade Federal de Goiás, 2023-02-28) Almeida, Fillipe de Paula; Teixeira, Antônio Heriberto de Castro;; Júnior, José Alves;; Alves Júnior, José; Souza, João Maurício Fernandes; Giongo, Pedro Rogerio; Ferreira, Manuel Eduardo; Pena, Diogo Silva
    Corn and beans are two of the main grains grown worldwide, with great importance in human and animal food. Corn cultivation is carried out mainly in the 1st and 2nd harvest, depending most of the time on rain and being vulnerable to dry spells. Likewise beans, which are mostly produced in the 2nd harvest. As a result, knowledge of crop evapotranspiration is essential to feed models for estimating and breaking productivity, managing water resources and managing irrigation. In this context, remote sensing becomes a viable alternative, with low operating costs and good accuracy. Thus, the objective of this work was to evaluate the performance of the Simple Algorithm For Evapotranspiration Retrieving (SAFER) algorithm in estimating the current evapotranspiration (ETa) of corn and bean crops in the northwest region of Goiás. Both studies were carried out in ItaberaíGoiás in an area irrigated by center pivot in the year 2021. The research was carried out in two parts: the first was to evaluate the impact of bolting on the calculated ET in an area cultivated with corn. Images from a MicaSense Altum multispectral and thermal camera coupled to a drone and three different sources of albedo images were used: Landsat 8, Sentinel 2A and drone. The albedo from the drone was obtained through the camera's reflectance images. The second part was to evaluate the impact of different albedo sources on the calculated ET, also using the camera images, but using four albedo sources. For this, an albedometer was installed in the field. The ET estimated by each source was determined with the ET obtained by the FAO method, Embrapa and climatological water balance from statistical indices. Tasseling in the maize crop contaminated the NDVI and albedo pixels, leading to a greater underestimation in the reproductive phase. On average, the MDE (mean square error) and AME (mean absolute error) were close to 1 mm day-1. Estimation of ET by remote sensing is not recommended for the reproductive phase of maize. Estimation of the ETa for the common bean crop is recommended from multispectral and thermal camera images, with both surface albedo sources. The confidence index ranges from 0.91 to 0.97. ETDroneAlb showed lower error compared to the standard methods.
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    Respostas da cultura do tomate para processamento industrial a fatores ambientais e irrigação
    (Universidade Federal de Goiás, 2023-02-16) Knapp, Fábio Miguel; Battisti, Rafael;; Alves Júnior, José;; Alves Júnior, José; Battisti, Rafael; Casaroli, Derblai; Evangelista, Adão Wagner Pêgo; Bezerra, Ricardo de Souza
    The tomato crop for industry is strongly conditioned by environmental conditions. In this way, this work aimed to determine the meteorological variable with the greatest influence and contribution to growth and the thermal sum accumulated in each stage of development of different hybrids, in addition to evaluating the responses of tomato plants in two irrigation systems: central pivot sprinkler and located by subsurface drip. For this, experiments were set up in Abadia de Goiás, Hidrolândia, Itaberaí, Palmeiras de Goiás, Piracanjuba and Silvânia during the 2020 harvest, fortnightly collections of plants were carried out for biometric measurement of number of leaves, leaf area, number of branches, number of fruit and plant height, as well as the collection of meteorological variables from each location with the aid of an automatic meteorological station, to determine the variable with the greatest interference in the growth and development of the crop, canonical correlation and multivariate Stepwise regression were used, in addition to separation of averages by Scott-knott. The main variable that affected crop growth was water availability. The water supply was responsible for 86.2% of the plant height and 79.6% of the leaf area index. On the other hand, the average air temperature, solar radiation and accumulated thermal sum showed little influence on crop growth. The industrial tomato responded to the accumulated degree days, with the average degree days accumulated in the first and second seasons of 1,394 and 1,364 degree days, respectively, and its average cycle of 124 and 116 days from transplanting to maturation. The irrigation systems did not show savings in the amount of water used in the crop during the cycle, but the subsurface drip irrigation system provided a shorter period of leaf wetness, improving plant health, delaying senescence and leaf abscission and providing greater productivity and increase in water use efficiency in this system.
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    Identificação molecular de helicoverpa armigera (Lepidoptera: Noctuidae)
    (Universidade Federal de Goiás, 2021-05-21) Oliveira, Thayssa Monize Rosa de; Tembrock, Luke Raymond; Gilligan, Todd Michael; Cunha, Marcos Gomes da;; Cunha, Marcos Gomes da; Timm, Alicia Eva; Dianese, Érico de Campos; Coelho, Regina Melo Sartori; Godinho, Karina Cordeiro Albernaz
    Previously found only on Old World continents, the caterpillar Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is capable of great economic damage, coming to be considered one of the most destructive agricultural pests. Its identification through morphological analysis is only possible with complex dissection of the adult male genitalia. The morphology of all phases of the life cycle, egg, larva, pupa and adult, is very similar with the morphology of other species of the genus, making the identification difficult. As it is a highly invasive pest and correct identification is the first step to be taken to decide the best management strategy, we realize the need for precise, easy and fast tools for the identification of this species. Thus, the objective of the work was to develop specific primers and to optimize different protocols for use in real-time PCR and digital PCR methodologies in order to identify H. armigera, even if this sample is of poor quality, only a fragment and/or is mixed with other species. For that, design, selection and optimization of primer and probe concentrations, primer annealing temperature gradients, tests and adaptations with different DNA extraction methods were carried out, with or without post-DNA extraction purification, tests with different ratios of H. zea and H. armigera mixed in the same reaction, determination of the maximum sensitivity in both methodologies and interpretation of the obtained data. We present the protocols developed to successfully identify the specie H. armigera, both with real-time PCR and digital PCR methodologies.