Brazil stands out in grain production, being the world's second-largest soya bean producer and the largest in Latin America. The area occupied by leguminous in the 2018/2019 harvest was 36 million hectares (CONAB, 2019). The Cerrado biome occupies about 44% of the country's agricultural area, which is responsible for 60% of total soya bean production (DICKIE, Magno, Giampietro, & Dolginow, 2016). The advance of agriculture in this biome is growing, which tends to further increase the percentage of crop production. In the Cerrado, the volume and frequency of rainfall is often fluctuating and insufficient, reducing the chances of adequate supply of the crop's water demand (Goes, Rodrigues, Arf, Arruda, & Vilela, 2011; Tardin et al., 2013). Therefore, it is common in Cerrado the soya bean crops to be subjected to drought stress conditions in their early stages, which can affect the germination process. The severity of the drought stress effect on soya bean depends on the

Seed size is an important indicator of physiological quality, since it may affect seed germination and seedling growth, especially under stress conditions. This study aimed to investigate the effects of seed size on germination and initial seedling growth, under salinity and water stress conditions. The treatments were arranged in a completely randomized design, in a 3 × 3 factorial scheme: three seed size classes (small, medium and large) and three stress treatments (control, saline or water stress), with four replicates. Water and salt stresses do not reduce the germination rate of medium and large seeds; however, the germination rate of small seeds is reduced under salt stress conditions. Drought stress drastically reduces the shoot growth of seedlings regardless of seed size, whereas root growth is higher in seedlings from medium and large seeds under water stress conditions. Under non-stressful environments, the use of large seeds is preferable, resulting in more vigorous seedlings with a greater dry matter accumulation. Medium-size seeds are more adapted to adverse environmental conditions and, therefore, should be used under conditions of water shortage and salt excess in the soil at sowing time. Seedlings are more tolerant to salinity than to water stress during the germination stage and initial growth under laboratory conditions.

In early soybean cultivars of high productive potential, the use of chemical nitrogen (N) fertilizer may be a critical factor to meet the crop N requirements for obtaining high yields. In order to determine the response of early soybean cultivars to doses and times of nitrogen fertilizer application, associated with the inoculation of Bradyrhizobium japonicum, two field experiments were conducted in a Quartzipsamment soil from the Brazilian tropical Savannah, during the 2016/2017 and 2017/2018 growing seasons. The experimental treatments were arranged in a 2 × 3 × 4 factorial scheme, being two soybean cultivars (BRS 1074 IPRO and ST 797 IPRO), three application times of N fertilizer (sowing, 30 and 50 days after the emergence) and four N doses (0 kg ha-1, 20 kg ha-1, 40 kg ha-1 and 60 kg ha-1). The following variables were evaluated: plant height, shoot dry matter, number of nodules, nodule dry matter, first pod height, number of pods, number of grains per pod, 1,000-grain mass, grain yield and harvest index. The use of N fertilizer did not improve the production components and did not increase the soybean grain yield, regardless of the doses and times of application. Therefore, it was concluded that, if efficient strains of B. japonicum are used in areas of first soybean crop, in a Quartzipsamment soil with medium-high fertility, especially with a relatively high N availability due to the mineralization of the soil organic matter, there is no need to apply starter or late doses of nitrogen fertilizer.

Nitrogen fertilization may interfere in the quality of soybean seeds. This study aimed to determine the physiological and sanitary quality of soybean seeds, in response to levels and times of nitrogen (N) application associated with Bradyrhizobium japonicum inoculation. Treatments were arranged in a randomized block design, in a 2 × 3 × 4 factorial arrangement [two soybean cultivars (BRS 1074 IPRO and ST 797 IPRO), three application times (sowing, 30 and 50 days after emergence) and four N levels (0 kg ha-1, 20 kg ha-1, 40 kg ha-1 and 60 kg ha-1), with four replicates. The 1,000-seed mass, moisture content, germination rate, seedling height, shoot length, primary root length, total seedling dry matter, electrical conductivity, mechanical damage, vigor and viability (tetrazolium test) and sanitary quality of the seeds were measured. The use of mineral N, associated with the inoculation of B. japonicum bacteria, does not prove to be consistent, in terms of its effects on the physiological quality of soybean seeds, although the incidence of pathogens may be reduced.

The economic and scientific interest in Hancornia speciosa Gomes (mangabeira) has increased in recent years, especially due to the commercialization of its fruits and the extraction of natural compounds with high pharmacological potential. This paper aims to determine and correlate the main physical and biometric characteristics of fruits and seeds of mangaba tree, as well as identifying the most appropriate substrate for the seedling emergence test. The following physical and biometric traits were measured in 100 fruits and 100 seeds: longitudinal diameter, transverse diameter, thickness, fresh mass, pulp fresh mass, volume, number of seeds. To identify the best substrate, a completely randomized design with two treatments (substrates) and ten replications of 20 seeds was used. The evaluated substrates were: sand and commercial substrate (Plantmax HT®). The shoot height, root length, stem diameter, total dry mass, and the relation between shoot height and stem diameter were evaluated at 50 days after sowing. Mangaba fruits and seeds showed great variations in their biometric traits, in addition to significant and positive correlation predominant in most characteristics. High fruit pulp yield can be optimized with the selection of plants with fruits show greater fresh mass due to the high degree of association between this characteristic and pulp yield. The use of the commercial substrate resulted in higher shoot height, greater number of leaves, and higher shoot height/stem diameter ratio.

A adubação nitrogenada pode afetar o processo de simbiose da soja com bactérias do gênero Bradyrhizobium (rizóbio), alterando a eficiência da fixação biológica de nitrogênio (FBN) e o crescimento das plantas. Portanto, objetivou-se com o trabalho avaliar o efeito de doses e épocas de aplicação de nitrogênio associada à inoculação de bactérias Bradyrhizobium japonicum, na nodulação e no crescimento inicial de duas cultivares de soja. O experimento foi realizado em condições de casa-de-vegetação, em Cassilândia (MS), Brasil, durante a safra 2016/2017. O delineamento experimental utilizado foi o de blocos casualizados, disposto em esquema fatorial 2 x 3 x 4, com quatro repetições. Os tratamentos foram constituídos por duas cultivares de soja (BRS 1074 IPRO e ST 797 IPRO), três épocas de aplicação (semeadura; 30 DAE e 50 DAE) e quatro doses de nitrogênio (0, 20, 40, 60 kg ha–1 de N). Aos 65 dias após a emergência das plantas foram avaliados o número de nódulos, volume dos nódulos, matéria seca dos nódulos, densidade dos nódulos, matéria seca da parte aérea, matéria seca das raízes e volume radicular. A adubação nitrogenada na cultura da soja, independente da época de aplicação e do cultivar, inibe o número de nódulos, volume dos nódulos e matéria seca dos nódulos e não proporciona aumento do volume radicular, matéria seca da parte aérea e do sistema radicular.

The size of the container can affect the quality of the seedlings and, there is no recommendation of containers for the formation of flamboyant seedlings [Delonix regia (Bojerex Hook.) Raf]. Thus, the objective of this study was to evaluate the production of flamboyant seedlings in different container sizes, besides performing trail analysis to identify the growth variables that characterize the quality of these seedlings. The experimental design was a randomized block design with seven container sizes (13 × 13 cm, 15 × 15 cm, 13 × 20 cm, 15 × 25 cm, 17 × 22 cm, 17 × 30 cm or 30 × 40 cm), with four replicates. Each experimental unit was composed of five containers, totaling 20 containers per treatment. The plant height, stem base diameter, number of leaves and the sturdiness quotient were measured at 20, 40, 60, 80 and 100 days after emergence (DAE), and at 100 DAE were also measured the root volume, root dry matter, shoot dry matter, total dry matter, shoot/root dry matter ratio and Dickson quality index (DQI). The flamboyant seedlings have better grow when cultivated in polyethylene bags with size of 30 × 40 cm. The collar diameter, root volume, root dry matter, shoot dry matter and total dry matter are the most adequate variables to indicate the quality of flamboyant seedlings. However, because it is a rapid, simple and non-destructive measurement variable, the root collar diameter is more adequate to identify high-quality flamboyant seedlings.

Numerous factors lead to the use of water with saline levels above those suitable for plant development, resulting in negative consequences on crops. Studies have sought techniques that aim to mitigate such consequences and the use of vitamins is promising, since these compounds improve the development conditions of vegetables. Thus, the study aimed to verify the ability of vitamins to mitigate the deleterious effects of using saline water, applied via irrigation during the formation of cucumber seedlings. Cucumber seeds were subjected to imbibition in three vitamin solutions (100 mg L-1thiamine; 100 mg L-1niacin; 50 mg L-1thiamine + 50 mg L-1niacin), in addition to two controls, both with water imbibition . After sowing, irrigation was carried out with saline water (100 mM NaCl), for all treatments, except for one of the controls. It was found that irrigation with saline water affected all variables studied, without, however, having a positive effect from the application of vitamins. Thus, it was concluded that the vitamins were not able to mitigate the deleterious effects caused by the application of saline water under the conditions in which the study was carried out and that future studies should be carried out to evaluate different concentrations and forms of application of the vitamins.