The supply of glutamic acid-based biostimulants may represent an innovative technology to increase oat grain yield and quality. The objective of this study is to measure the effect of different biostimulants based on concentrations of glutamic acid and nutrients and their application on indicators of productivity and industrial and chemical quality of oat grains. The study was conducted in 2016 and 2017 in a randomized block design with four replications, considering 10 combinations of treatments for different application conditions and types of glutamic acid-based biostimulants, which were: 1. Control; 2. Zinplex (seed) + Biomol (grain filling); 3. Zinplex (seed) + Glutamin Extra (grain filling); 4. Zinplex (seed) + Biomol (thinning); 5. Glutamin Extra (1st fungicide application) + Glutamin Extra (2nd fungicide application); 6. Biomol (1st fungicide application) + Biomol (2nd fungicide application); 7. Zinplex (seed) + Vorax (grain filling); 8. Vorax (1st fungicide application) + Vorax (2nd fungicide application); 9. Biomol (thinning) + Vorax (grain filling) and 10. Biomol (thinning) + Glutamin Extra (grain filling). The foliar application of biostimulants with the presence of glutamic acid and nutrients may have positive effects on variables related to productivity and industrial and chemical quality of oat grains, however, depending on the agricultural year conditions. The application of Glutamin Extra in the 1st and 2nd fungicide application shows the best results in the vast majority of grain yield and quality variables, but the costs involving only biostimulants do not guarantee economic viability.

No abstract

The artificial neural networks modeling might simulate the efficiency of wheat grain yield involving biological and environmental conditions during the development cycle.  Considering the main succession systems in wheat crop in Brazil, the study aimed to adapt an artificial neural network architecture capable of predict the wheat grain productivity throughout the growth cycle, involving nitrogen and non-linearity of maximum air temperature and rainfall. The field experiment was conducted in two successions systems (soybean/wheat and maize/wheat) in 2017 and 2018, the trial design was in a randomize blocs with eight replicate in the level 0, 30, 60, and 120 kg ha-1 N-fertilizer doses in the phenological stage of third fully expanded leaves. Every 30 day of the development cycle were obtained the biomass yield, maximum air temperature and accumulated rainfall information. The perceptron multi-layered artificial neural networks with backpropagation algorithm with network architecture 5-8-1 and 5-7-1 in soybean/wheat and maize/wheat system respectively, is able to simulate the wheat grain yield involving the nitrogen dose at top-dressing and the non-linearity of maximum air temperature and rainfall with biomass information obtained during the cycle crop.

Analysis of the relationship of oat grain chemical components with productivity can yield information that determines crop production strategies. The market values high protein grain, but production and other nutritional components may be affected in the effort to increase protein levels. The objective of this study was to determine how the dynamics of the components of oat grain chemical composition relate to productivity when adding nitrogen to the soil, in order to develop nutrient management strategies that can combine productivity with grain quality. The study was conducted from 2011 to 2016 in Augusto Pestana, Brazil, in a randomized block design with four replications in a 4x2 factorial design for nitrogen rates (0, 30, 60 and 120 kg.ha-1) and standard biotype oat cultivars used on a commercial scale (Barbarasul and Brisasul) in two succession systems soybean/oat and corn/oat, totaling 64 experimental units. The nitrogen doses were applied at the phenological stage of expanded fourth leaf using urea. The increase of nitrogen fertilization for topdressing promoted increase of the total protein of oat grains and reduction of the total fiber in both soybean/oat and corn/oat systems. Higher levels of grain protein due to nitrogen fertilization reduced grain production, regardless of the cropping system.

The most efficient nitrogen management by adjusting the nutrient dose at sowing and top-dressing with the supply period can increase the oat yield with greater sustainability. Considering the main cereal succession systems in Brazil and independent of the agricultural year condition, the objective of the study was to propose combination of nitrogen adjusted dose at sowing and at top-dressing with the most adequate moment of supply over the biomass and oat grain yield. The experiment was conducted in the years 2015, 2016 and 2017, in Augusto Pestana, RS, Brazil. The experimental plot was a randomized block design with four replicates, in a 4 x 4 factorial model, and four nitrogen rates at sowing (0 - control sample, 10, 30 and 60 kg ha-1), changing the top-dressing dose at total of 70 and 100 kg ha-1 in soybean / oat succession system and maize / oats, respectively. Expecting 4000 kg ha-1 of grain yield, with top-dressing supply in four periods (0, 10, 30 and 60 days after the emergency). The nitrogen management in oat, the combination of the adjusted dose at sowing and at top-dressing with the supply season shows the need to combine the technical recommendations of fertilization with the meteorological conditions of cropping. The absence of nitrogen at sowing and total dose applied at top-dressing, 30 to 35 days after emergence, increased the biomass and grains yield, regardless of condition of the agricultural year and succession system