Seed deterioration is an important topic in plant science, as the majority of cultivated species use seeds as their means of propagation; however, due to its complexity, the process of seed deterioration has not yet been completely elucidated. Three soybean cultivars (BMX Raio, BMX Zeus, and DM 53i54) exposed to four distinct periods of accelerated aging (0, 3, 6 and 9 days) in a fully randomized experimental design. Initially, vigor and germination tests were performed. The activity of superoxide dismutase, catalase, ascorbate peroxidase enzymes, hydrogen peroxide, malonaldehyde, DNA oxidation, macromolecules and mineral content, and Maillard reactions were quantified in the embryonic axis. Results showed that DNA did not suffer degradation or oxidation. In terms of consumption of reserves, only sugars were consumed, while levels of protein, starch, and triglycerides were maintained. The Maillard reaction did show potential as an indicator of buffer capacity of protein to ROS. Additionally, levels of catalase and ascorbate peroxidase decreased during the aging process. Moreover, nutrient analysis showed that a high magnesium level in the cultivar bestowed greater resilience to deterioration, which can indicate a potential function of magnesium in the cell structure via reflex in seed aging through seed respiration.

The differentiation of seedling growth and development is the result of the vigor level of the seed lot. Because of this, knowing the seedling growth curve is essential for the evaluation of the seedling length test, to be carried out at the moment when any differences in vigor really manifest, thus being able to reduce the time of evaluation of the test. In this research, the objective was to determine the most efficient time interval to perform the seedling length test in soybean seeds, depending on the vigor levels. The evaluated characteristics were percentage of seed germination, first germination count, emergency, days for emergence, aerial, root and total length (evaluated every 12 hours), aerial, root and total dry mass in completely randomized design. High vigor seeds originated seedlings with higher growth rates (cm. h-1), with vigor being one of the factors that interfere in the seedling length test. After 96 hours of the seedling length test, there was a statistical differentiation between the three vigor levels tested. The soybean seedling length test between lots, with different vigor, can be performed 96 hours after sowing.

The current study investigated the fungal diversity in freshly harvested oat samples from the two largest production regions in Brazil, Paraná (PR) and Rio Grande do Sul (RS), focusing primarily on the Fusarium genus and the presence of type B trichothecenes. The majority of the isolates belonged to the Fusarium sambucinum species complex, and were identified as F. graminearum sensu stricto (s.s.), F. meridionale, and F. poae. In the RS region, F. poae was the most frequent fungus, while F. graminearum s.s. was the most frequent in the PR region. The F. graminearum s.s. isolates were 15-ADON genotype, while F. meridionale and F. poae were NIV genotype. Mycotoxin analysis revealed that 92% and 100% of the samples from PR and RS were contaminated with type B trichothecenes, respectively. Oat grains from PR were predominantly contaminated with DON, whereas NIV was predominant in oats from RS. Twenty-four percent of the samples were contaminated with DON at levels higher than Brazilian regulations. Co-contamination of DON, its derivatives, and NIV was observed in 84% and 57.7% of the samples from PR and RS, respectively. The results provide new information on Fusarium contamination in Brazilian oats, highlighting the importance of further studies on mycotoxins.

The objective of this work was to decompose the variations of the genotype × environment interaction through fixed multivariate models, as well as to understand the genetic variations through mixed models, for the estimation and prediction of the genetic value of soybean (Glycine max) genotypes in the state of Rio Grande do Sul, Brazil. Tests were carried out during the 2016/2017, 2017/2018, and 2018/2019 crop seasons in different municipalities in six regions of the state, using the additive main effects and multiplicative interaction (AMMI) and genotype main effects + genotype-by-environment interaction (GGE) models. The genotypes were also evaluated using an index that allows weighting between mean performance and stability (WAASBY) and by the restricted maximum likelihood (REML) and the best linear unbiased prediction (BLUP) models. The used experimental design was randomized complete blocks (18 environments x 12 genotypes), with three replicates. The best performing genotypes in favorable environments are: 'BMX Valente RR', 'BMX Alvo RR', 'NS 5959 IPRO', 'DM 5958RSF IPRO', and 'BMX Ativa RR'. The favorable environments are the 2017/2018 season in the municipality of Bagé and the 2016/2017 season in the municipalities of São Luiz Gonzaga and Cachoeira do Sul, where higher grain yields were obtained. The genotypes that show excellent performance in unfavorable environments are cultivars BMX Ativa RR, DM 5958RSF IPRO, NS 5959 IPRO, and TMG 7262 RR. The 2016/2017 season is considered unfavorable in the municipalities of São Luiz Gonzaga and Cachoeira do Sul. The AMMI, GGE, and WAASBY or BLUP models for genotype selection must be used simultaneously.

Background: Based on their nutritional benefits, oat is classified as a cereal of great importance for both human and animal feeding. Throughout the production process, species and variety identification are vital for agricultural systems. The present work establishes SeedFlow, a method for image acquisition, processing, and classification of oat grains using deep learning techniques. We apply these techniques to the identification of the grains from the different oat species Avena sativa and Avena strigosa and to classify grains as varieties of Avena sativa, such as UPFA Ouro, UPFA Fuerza, and UPFA Gaudéria. Results: To achieve this proposition, we executed our solution considering six different deep learning architectures to evaluate which model presents the best performance. This approach attained an accuracy of 99.7% for oat species identification and 89.7% for oat varieties classification using DenseNet architecture. Conclusions: As a result, this tool can provide high value for practical quality control applications, and it is feasible to use in pre-screening tests, laboratory analysis pipelines, or computer support tools geared toward breeding programs or intellectual property assessment.

Ryegrass (Lolium multiflorum Lam.) is the main winter weed of crops in Southern Brazil. High competitiveness, adaptability, widespread resistance to herbicides and seed dormancy make the plant a permanent problem. Herbicides, as well as plant growth regulators, can be used as a management option for ryegrass seed production, however there is no consensus among authors at which stage of the plant the application is most effective. Thus, this study aimed to evaluate the production and physiological quality of ryegrass seeds in response to the application of herbicides and plant growth regulators in three stages of plant development (inflorescence emergence, flowering and fruit development). Each treatment consisted of applying two different doses of each of the active ingredients: ammonium glufosinate, clethodim, glyphosate, iodosulfuron-methyl, paraquat and 2,4-D (herbicides); ethephon and trinexapac-ethyl (plant growth regulators), still an untreated control, totaling 17 treatments for each stage of development. The experimental design used was randomized blocks, with three replications. The variables evaluated were: seed production (kg ha⁻¹), thousand seed weight (g), viability (%), germination (%), first germination count (%), dormant seeds (%) and dead seeds (%). The ryegrass seed production reduced 100% with clethodim, glyphosate, ammonium glufosinate or paraquat applied in the inflorescence emergence or flowering stages. In the fruit development stage, all treatments (herbicides and plant growth regulators) caused deleterious effects on seed production, the greatest effect occurred with paraquat (95%). Paraquat, ammonium glufosinate and clethodim affected the physiological quality of the seeds when applied in fruit development stage. This research demonstrated that the application of herbicides in the ryegrass reproductive stage decreases its seedbank replenishment (natural re-sowing), with the potential to harm its progeny.