This study aimed to evaluate the plant growth regulator application, in different doses, on priming, with and without water restriction, in corn seeds. Evaluations were carried out in two periods (0 to 30 days of storage), with treatments consisting of seeds primed in water (0.0 MPa) and polyethylene glycol 6000 solution (-0.4 MPa), with or without plant growth regulator added in different doses, plus a control group. The amount of plant growth regulator was standardized by the gibberellic acid concentration in the commercial product, adopting the doses zero, 1, 2 and 3 mg of gibberellic acid. L-1 solution. After priming, the seeds were dried in an oven with forced air circulation for nine hours, and evaluated for water content, percentage and first count of germination, percentage of abnormal seedlings and non-germinated seeds, cold test, seedling length and dry weight and vigor index. Priming with water restriction -0.4 MPa, in solution of polyethylene glycol 6000, improves the vigor; however, the addition of plant growth regulator in priming does not provide increase in corn seeds quality. Corn priming in water, regardless the addition of plant growth regulator, reduces the ability of the seeds to withstand storage.

This study aimed to evaluate the bromatological traits of Brachiaria brizantha cv. Piatã submitted to different cutting heights and nitrogen (N) rates. A randomized complete block design with sixteen treatments and four replications was used. The treatments arranged in 4x4 factorial arrangement, comprised four cutting heights (8, 16, 24 and 32 cm) and nitrogen rates (0, 100, 200, 300 kg N ha-1). N rates were applied after a standardization cutting. Agronomic traits comprised number of tillers, dry mass, leaf blade pseudocolus ratio and amount of senescent material. Bromatological traits of morphological components leaf blade and pseudostem comprised crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and mineral matter (MM). In the first and second cuttings, maximum yields were obtained at 16 and 32 cm cutting heights combined with N rates of 180.5 and 230.5 kg ha-1, respectively. No interaction was observed between N rates and cutting heights. It was concluded that 16 and 24 cm cutting heights combined with N rates of 200 and 300 kg ha-1 improved agronomic and bromatological traits of Brachiaria with a better efficiency in pasture system.

Considering that nitrogen is the main macronutrient limiting pasture productivity, the aim of this study was to investigate the most appropriate day for nitrogen fertilization of the grasses Brachiaria brizantha BRS Piatã and Panicum maximum BRS Quênia. The experiment was conducted in a greenhouse in the city of Rondonópolis, located in the state of Mato Grosso, Brazil, using a completely randomized design. The treatments consisted of five nitrogen fertilization periods: 0; 2; 4; 6 and 8 days after defoliation. The dry mass of the leaf blade (DMLB), dry mass of stem + sheath (DMSS), dry mass of residue (DMRES) and root dry mass (RDM) were evaluated. The non-structural carbohydrate of the grass roots was also quantified. The later nitrogen fertilization after defoliation reduced DMLB (P< .01) and DMSS (P< .01) of the BRS Piatã palisadegrass, and DMRES of both grasses (P< .01). Higher levels of water soluble carbohydrates were observed when nitrogen fertilization was performed on grass cutting (day 0). Nitrogen fertilization of the BRS Piatã palisadegrass close the time of defoliation is recommended. For Quênia guineagrass, nitrogen can be applied between the cutting day and the eighth day after defoliation. For the root system, there is a higher content of water soluble carbohydrates in the BRS Piatã palisadegrass and greater accumulation of starch in the BRS Quênia guineagrass.

The goal was to evaluate the chemical composition and fermentation pattern of elephant grass (Pennisetum purpureum Schum. cv. Roxo) silage with different levels of soybean hulls or rice bran. Two trials were conducted, comprising of a completely randomized design, with four replicates each. Treatments consisted on the addition of 0%, 5%, 10%, and 15% of soybean hulls or rice bran to unwilted green elephant grass forage. Large PVC silos were used adopting a density of 600 kg of green mass m -3 . The silos were opened 40 days after ensiling. The results revealed that the inclusion of 10% soybean hulls increased elephant grass forage dry matter (DM) content to 31%, but did not alter the water soluble carbohydrate (WSC) content or buffering capacity. The resultant silages exhibited good fermentation patterns in terms of pH (less than 3.97) and NH 3 -N (4.07% total N) levels. The inclusion of rice bran increased both DM and WSC content in the forage, improving the fermentation pattern of silages (P < 0.05). This too was verified by a pH lower than 3.92 and a maximum NH 3 -N of 4.23% of the total N. The inclusion of 10% rice bran to the elephant grass improved the nutritional value of the forage to be ensiled and, hence, of the produced silage. Key words: Additive. Ammonia nitrogen. pH. Pennisetum purpureum. Silage. Water soluble carbohydrates. ResumoObjetivou-se avaliar a composição bromatológica e o padrão de fermentação da silagem de capimelefante (Pennisetum purpureum Schum. cv. Roxo) aditivada com níveis de casca de soja e de farelo de arroz. Foram realizados dois experimentos para avaliar o uso de aditivos na ensilagem de capim elefante. Utilizou-se delineamento experimental inteiramente casualizado, com quatro repetições. Os tratamentos consistiram na adição de 0, 5, 10 e 15% do aditivo na massa verde de forragem de capim-elefante picada e sem emurchecimento. Foi utilizado silos de PVC, adotando densidade de 600 kg de massa verde m -3 , com abertura do silo 40 dias após a ensilagem. A inclusão de 10% de casca de soja aumentou o teor de matéria seca (MS) da forragem de capim-elefante para 31%, porém não alterou os teores de carboidratos solúveis (CHOS) e poder tampão. As silagens de capim-elefante obtidas apresentaram bom padrão fermentativo, com valores de pH inferior a 3,97 e de N-NH 3 , 4,07% do N total. A inclusão de farelo de arroz proporcionou melhoria no padrão fermentativo das silagens produzidas, verificado pelo pH inferior a 3,92 e N-NH 3 máximo de 4,23% do N total. A inclusão de 10% de farelo de arroz na ensilagem do capim-elefante melhorou o valor nutritivo da forragem a ser ensilada e, consequentemente, da silagem produzida. Palavras-chave: Aditivo. Carboidratos solúveis. Nitrogênio amoniacal. Pennisetum purpureum. pH. Silagem.

The integrated crop-livestock system (ICLS) is a model of sustainable cultivation that allows the recovery of degraded pastures and the intensification in pasture and grain production. However, the presence of pathogens in the production fields has hampered the employment of these systems. In order to minimize or eradicate the phytonematodes in the production fields and the seeds used in CLIS, it is necessary to know the nematofauna. Based on this, this work aimed to perform a literature review describing the main forages and agricultural crops used in integrated crop-livestock systems in tropical regions, the major phytonematodes associated with these crops and their control measures. This work was based on a literature review from the Scielo, Scopus and Google Scholar databases, with data from 1999 to 2019. The initially used keywords were "tropical weeds"; "Agricultural crops"; and "ICLS" and their respective terms in the Portuguese language. From the initial results, we used the keywords "Brachiaria syn. Urochloa sp. "; "Phytonematodes"; "Millet"; "Maize"; "Panicum sp."; "Soy"; "Sorghum", and "ICLS" and their respective terms in the Portuguese language. Publications that did not meet the criteria of this study (analyzed by titles and abstract) were considered as exclusion criteria, as well as repeated works in the databases. Based on the literature, the cultivation of forages belonging to the genera Brachiaria syn. Urochloa sp. and Panicum sp., along with and soybean, maize, sorghum and millet are predominant in the ICL system of tropical regions. The phytonematodes Meloidogyne sp., Pratylenchus brachyurus, Heterodera glycines, Rotylenculus reniformis, Aphelenchoides sp., Ditylenchus sp. and Filenchus sp. cause greater severity of damage to the main cultures used in ICL. No control method can eradicate the phytonematodes. The most effective control for the studied phytonematodes is through integrated pest and disease management.

Integrated production systems were developed to preserve productive resources and maintain the profitability of agribusiness. However, the use of seeds of low physiological and sanitary quality and the implantation of agricultural and forage crops in production fields of low sanitary quality may favor the dissemination and proliferation of phytopathogens such as fungi. Therefore, using the scientific literature, this work aimed to identify the fungi associated with the main agricultural and forage crops that cause damage to the integrated production systems of Brazilian tropical regions and their control measures. This work was based on a literature review in the Scielo, Scopus and Google Scholar databases, with data obtained between 1999 and 2019. The keywords employed were “fungus”, “tropical grass”; “agricultural crops”; “ICLS” (Integrated Crop-Livestock); and “ICLF” (Crop-Livestock-Forest) and their respective terms in Portuguese, under different combinations. For the inclusion criteria, publications (papers, books, theses, dissertations, and scientific communiqués) from 1999 to 2019 which fit the study aim were selected, both in the Portuguese and English languages. The publications that did not meet the criteria of this study and were repeated in databases were considered as exclusion criteria. The main fungi associated with forage and agricultural crops and soils of integrated systems of Brazilian tropical regions are Bipolaris sp., Curvularia sp., Exserohilum syn. Helminthosporium sp., Phoma sp., Fusarium sp., Macrophomina sp., Pythium sp., Rhizoctonia sp. and Sclerotium sp. The main methods of fungal control are the use of quality seeds, crop rotation, resistant cultivars, and chemical seed treatment.

Data regarding the mixing of palisade grass seeds with fertilizers are scarce and contradictory. The aim of this study was to evaluate the maximum contact time without significant damage on physiological quality of Piatã grass seeds when mixed with 05:25:15 NPK fertilizer. The experiment was conducted in a completely randomized design with six treatments and four replications. Treatments consisted of six contact times of the seeds with the fertilizer: 0, 24, 48, 72, 96 and 120 hours. The variables following variables were evaluated: water content, germination percentage, first germination count, seed viability, eletrical conductivity, accelerated aging, emergence percentage and emergence speed index. Except for the water content, there was an effect of the fertilizer contact times with the seeds over all variables. There was a decreasing linear effect of the contact time of the seeds with the fertilizer for all variables, except for electrical conductivity. The average water content of 10.09% was observed. After 120 hours of the fertilizer/seeds mixture, a reduction of 36.4% was observed in germination, of 36.7% in the first germination count, of 25.0% in seed viability, and of 65.0% in the germination of seeds subjected to the accelerated aging. There was an increase of 170.0% in the electrical conductivity of the Piatã grass seeds. The minimum standard of 60% germination, viability or emergence, required for the commercialization of forage seeds, should be maintained to ensure the ideal forage population in the establishment of the crop. Based on the emergence and viability tests, the commercialization levels can be maintained by performing the fertilizer/seeds mixture up to 63 hours before sowing. After 63 hours of seed and fertilizer mixing, a reduction of the initial vigor of the seeds can be observed, although not compromising the crop establishment or causing degradation of soil. Therefore, Piatã grass seeds can be mixed with the 05:25:15 NPK fertilizer up to 63 hours before sowing.

The present work aimed to evaluate the correlation of the agronomic characteristics of sunflower genotypes grown for seven years in the state of Mato Grosso, Brazil, as an aid for the indirect selection of genotypes. The data were obtained from experiments conducted in the period from 2009 to 2017, in the municipality of Campo Verde, Mato Grosso state, Brazil, using different sunflower genotypes. Pearson correlation analysis was performed between the following agronomic characteristics: Initial flowering (IF), physiological maturation (PM), plant height (PH), thousand achene weight (TAW), achene yield (AY), oil content (OC) and oil yield (OY). A strong positive correlation (r = 0.75*) was observed between IF and AY, and a moderately strong positive correlation (r = 0.67*) between PM and AY. There was a negative correlation (r = -0.51*) between TAW and OC, as well as between plant height and achene yield (r = -0.32*) and oil yield (r = -0.34*). Late-cycle genotypes showed a positive correlation with achene yield and oil yield. Smaller plants favor productive parameters. Further studies and the anticipation of the crop sowing season in the second crop are suggested due to the local edaphoclimatic conditions.