Nitrogen fertilization affects ‘Tifton 85’ bermudagrass (Cynodon spp.) herbage accumulation (HA) and nutritive value; however, forage response may be affected by N fertilizer source, application levels, and environmental conditions. This 2‐yr study evaluated the effect of different N fertilization strategies on Tifton 85 bermudagrass responses in a tropical soil from southeast Brazil. Treatments were two N sources (ammonium nitrate [AN] and urea) applied at 0, 60, 120, 180, and 240 kg N ha−1 harvest−1. Fertilizer sources were enriched with 15N to quantify the recovery of fertilizer‐derived N. Forage was harvested at 30‐d intervals to evaluate HA and shoot N concentration. Leaf area index (LAI), intercepted photosynthetically active radiation (PARi), and chlorophyll index were measured 1 d before harvest. Ammonium nitrate and urea resulted in similar Tifton 85 HA. Maximum Tifton 85 HA (4.6 Mg ha−1) was reached at the fertilization level of 210 kg N ha−1 harvest−1 while critical shoot N concentration, herein defined at 90% relative production, was 23.7 g kg−1. Similarly, critical PARi and LAI were 71% and 4.7 m2 m−2, respectively. Nitrogen recovery in the plant and soil was greater for urea (52%) than AN (41%). Despite the relatively greater shoot N accumulation, N recovery decreased as N levels increased. Nitrogen application level should be adjusted to optimize HA, nutritive value, and N recovery.

High maize (Zea mays, L.) yields require an adequate supply of N fertilizer. As an alternative, fertilizers with nitrification and urease inhibitors have emerged onto the market to increase N supply to crops. The objective of this study was to determine the effects of urea treated with nitrification and urease inhibitors on plant growth and grain yield. The experiment was performed in a weathered tropical soil, in the 2013/2014 and 2014/2015 crop seasons. Fertilizer treatments were four N levels (0, 50, 100, and 200 kg ha-1 N); three urea treatments (urea with urease inhibitor: [N-(N-butyl) thiophosphoric triamide]-NBPT; urea with nitrification inhibitor: (3,4-dimethylpyrazole-phosphate)-DMPP; and conventional urea) and two application strategies (total N applied at sowing; and 30 kg ha-1 N at sowing and the remainder topdressed once plants had four completely developed leaves). Critical levels for chlorophyll index (CI), leaf N concentration, leaf area index (LAI), and N levels were 52.7, 27.5 g kg-1 , 4.3 m 2 m-2 and 110 kg ha-1 , respectively. Addition of inhibitors and split N application did not increase growth, nutrition or yield compared to conventional urea and total N applied at sowing. However, increase of N levels increased grain yield by up to 185 kg ha-1 N. On the other hand, agronomic N use efficiency linearly decreased as N levels increased. It can be concluded that N sources and application strategies were not significant factors in grain yield. Therefore, N from conventional urea might be applied solely at sowing.

The objective was to evaluate the leaf area index of six different grasses. The experiment was installed at the Instituto Federal de Tecnologia e Educação of Uberaba, using a randomized block design with split plots in time. The plots were sown: Brachiaria decumbens cv. Basilisk, Brachiaria brizantha cv. Marandu, Panicum maximum cv. Mombasa, Panicum maximum cv. Tanzania, Brachiaria brizantha cv. Xaraes, Cynodon dactylon hb. Tifton and the plots, ten seasons of evaluation in 10 x 6 factorial arrangement with four replications. Rates of leaf area of each forage at different times of year were evaluated. Compared to other forage species, Panicum maximum had a higher leaf area index when subjected to periodic fertilization and irrigation. Only in the late fall Brachiaria Xaraés IAF had increased, but did not differ significantly from the others. Key words: Leaf area, times, grass AbstractObjetivou-se avaliar o índice de área foliar de 6 diferentes gramíneas forrageiras. O experimento foi instalado no Instituto Federal de Educação Tecnológico de Uberaba utilizando delineamento em blocos ao acaso em parcelas subdivididas no tempo. Nas parcelas foram semeadas: Brachiaria decumbens cv. Basilisk, Brachiaria brizantha cv. Marandu, Panicum maximum cv. Mombaça, Panicum maximum cv. Tanzânia, Brachiaria brizantha cv. Xaraes, Cynodon dactylon hb. Tifton e nas subparcelas, dez épocas de avaliação em esquema fatorial 6 x 10 com quatro repetições. Foram avaliados os índices de área foliar de cada forrageira em diferentes épocas do ano. Comparadas com as outras espécies forrageiras, o Panicum maximum apresentou maior índice de área foliar quando submetido à adubação periódica e irrigação. Apenas no final do outono a braquiária xaraés apresentou IAF maior, mas, não diferenciou estatisticamente das demais.

ResumoO cultivo de canola (Brassica napus, L.) foi incentivado para produção de grãos para óleo na década de 1980, e também considerada boa opção para rotação de culturas. O nitrogênio é um dos nutrientes mais exigidos pela planta para aumento na produtividade, enquanto que o enxofre é essencial para proporcionar qualidade às sementes. Assim, objetivou-se avaliar, na região do Cerrado, os efeitos da adubação com nitrogênio e enxofre na produtividade e nos teores de óleo e proteína bruta nos grãos. Procurou-se, ainda, relacionar com a produtividade de grãos os teores de S no solo e as concentrações de N e S na folha diagnóstica. O experimento foi realizado no município de Uberaba, MG, em Latossolo Vermelho distrófico, textura média, utilizando-se o híbrido Hyola 401. Os tratamentos foram gerados pelo esquema fatorial 5 x 4 (cinco doses de N: 0, 60, 100, 140 e 180 kg ha -1 e; quatro doses de S: 0, 15, 30 e 60 kg ha -1 ) e dispostos em delineamento em blocos ao acaso, com quatro repetições. A adubação nitrogenada e sulfatada aumentou a produtividade de grãos de canola, sem alterar significativamente os teores de óleo e proteína bruta. Doses superiores a 140 kg ha -1 de N e 15 kg ha -1 de S proporcionaram produtividades de grãos acima de 1100 kg ha -1 . Parcelas com produtividades de grãos superiores a 1000 kg ha -1 apresentaram concentrações de N foliar acima de 52 g kg -1 . Os maiores teores de S foram observados na camada de 15-30 cm, comprovando mobilidade do ânion sulfato. As menores produtividades de grãos foram observadas quando os teores de S no solo nessa camada estavam menores que 4 mg dm -3 . As concentrações de N na folha diagnóstica e os teores de S-SO 4 -2 na camada de 15-30 cm relacionaram-se positivamente com a produtividade da cultura. Palavras-chave: Brassica napus, nitrogênio, enxofre, óleo, proteína AbstractThe canola (Brassica napus, L.) cultivation was encouraged for grain and oil production at the 80's, and it is also considered a good option for crop rotation. The nitrogen is one of the most required nutrients by the plant to increase its production, while sulfur is essential to provide seed quality. Thus, the objective of this study was, at Cerrado region, evaluate the effects of nitrogen and sulfur fertilization at yield and contents of oil and crude protein in the grains. We also sought relate to grain yield the S content in the 1 Parte da dissertação de mestrado do primeiro autor.

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RESUMO:O girassol (Helianthus annuus, L.) pode ser utilizado na fabricação de ração, silagem, óleo para consumo humano, na floricultura e alimentação de pássaros, além de ser excelente matéria prima para produção de biodiesel. O objetivo do presente trabalho foi avaliar as características agronômicas de 18 genótipos de girassol na época da safrinha em Uberaba, Minas Gerais. O experimento foi instalado no dia 10/03/2009, utilizando-se o espaçamento de 0,75 m entre linhas. O ensaio foi conduzido em delineamento em blocos ao acaso (DBC). Os tratamentos foram constituídos por 18 cultivares. Houve diferença significativa (p<0,05) em relação ao rendimento de aquênios, em que quatro cultivares apresentaram produtividade superior à média geral. Também, foi constatada diferença (p<0,05) em relação à altura de planta e altura de capítulo. A cultivar HLT 5004 foi inferior às demais apresentando o menor valor em massa de 1.000 aquênios. As cultivares ZENIT, EXP 1452 CL, AGROBEL 960 (T) e M 734 (T) foram superiores às demais apresentando os maiores valores de tamanho de capítulos. Em relação ao número de dias após a semeadura em que cada cultivar entrou no florescimento e atingiu o estádio reprodutivo, observaram-se médias baixas indicando que são cultivares de ciclo mais curto. O girassol pode ser utilizado na época da safrinha como mais uma opção no esquema de rotação de culturas em Uberaba/MG. Palavras-chave:Helianthus annuus. Rendimento de grãos. Estádio reprodutivo. Safrinha. PHENOLOGY ASSESSMENT OF CULTIVARS OF SUNFLOWER (Helianthus annuus L.) IN UBERABA, STATE OF MINAS GERAIS, BRAZIL -HARVEST 2009 SUMMARY:The sunflower (Helianthus annuus L.) can be used in manufacturing of ration, silage, oil for human consumption, in floriculture and feeding birds, as well as being excellent raw material for biodiesel production. The objective of this study was to evaluate the agronomic characteristics of 18 sunflower genotypes during the second crop in Uberaba, State of Minas Gerais, Brazil. The experiment was installed on March 10 th 2009, using the 0.75 m spacing between rows. The trial was conducted in a randomized block design (RBD). The treatments consisted of 18 cultivars. There was a difference (p<0,05) in the yield of grain and only four cultivars shown higher yield than the overall average. Also, significant differences (p<0,05) were observed in relation to plant height and height of the chapter. Cultivar HLT 5004 was lower than all showing the lowest weight of 1,000 seeds. Cultivars ZENIT, EXP 1452 CL, AGROBEL 960 (T) and M 734 (T) were superior to others with higher rates of size chapters. Regarding the number of days after sowing in each cultivar entered the flowering and reached the reproductive stage, there were low averages are indicating that cultivars with a shorter cycle. The sunflower can be used as an off-season option in the crop rotation scheme in Uberaba/MG.

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Tomato cultivation is challenging due to the high susceptibility to various pests and diseases. Fruit borer insects make fruits unfeasible for commercialization because this favors colonization by pathogens. The loss due to borers can be avoided by bagging the bunches of fruit, helping the conventional crop to be more sustainable, reduce the use of pesticides, reduce the residue in fruits and improve the quality of life of rural workers, by less exposure to agrochemicals and poisoning problems. The results are products of better quality and with the possibility of better profitability. The objective of this study was to evaluate the efficiency of tomato bagging in the control of fruit borer insects, and its effects on lycopene content, taste, productivity and profitability. The experiment was conducted in a field in the municipality of Uberaba-MG, from November 2016 to September 2017. The experimental design was a randomized block design, in a 3 x 5 factorial, with four replications. The factors consisted of three tomato hybrids: Dominador (salad), Ravena (Italian) and Carina Star (Santa Cruz), and fruit bagging types, made by TNW (tissue-non-woven), tulle, organza, brown craft and a control, without fruit bagging. The decision of bagging use depends on the pest incidence in the area and the change in the agronomic characteristics of the tomato. The organza and tulle fruits bagging reduce the incidence of borer insects, relative to the control, in the cultivation in spring-summer. The Dominador presents higher brix content among the evaluated hybrids. Carina Star, when bagged with organza, produces fruits with higher levels of lycopene, and is 116% superior to the other cultivars. From the second harvest, organza fabric is the most profitable bagging, since it is the only one that can be reused several times and is therefore more sustainable.