Objective: The objective of this research was to evaluate plant growth, soybean grain yield and production cost depending on the use of different populations. Theoretical reference: Among management practices, plant population is an extremely important stage for the establishment of soybean crops. In many cases, just changing the plant population is enough to result in high gains in crop grain productivity. Methodology: A randomized block design was used, with four treatments and four replications. The treatments consisted of densities of 200, 250, 300 and 350 thousand seeds ha^-1. Plant height, insertion height of the first pod, number of pods per plant, number of grains per pod, mass of one thousand grains and grain productivity were evaluated. Results and conclusion: Populations influenced grain productivity, with the highest productivity being achieved in the population of 250 thousand, 5905 kg ha^-1. It was concluded that sowing density affects the number of pods per plant and soybean grain productivity. The density of 250 thousand seeds ha^-1 was the one that provided the highest productivity of soybeans and the lowest sowing cost. Research implications: Determining the best population of soybean plants in different locations is essential to reduce producer costs. Originality/value: Most research works focus on the use of inputs, disregarding that the plant population can affect crop performance and production costs.

The intensive use of land to produce vegetables results in high soil degradation and cultivated area. The use of techniques and resources that make production possible under unfavorable conditions can be decisive for agriculture. Thus, this study aimed to evaluate the isolated and joint effects of liming and thiamine application on the development of bell pepper plants. The treatments consisted of three different soil base saturation (36, 60, and 80%), combined with foliar application of thiamine (with and without) at a concentration of 100 mg L-1. It was found that thiamine mitigates the effects of low base saturation on the physiological traits of bell pepper plants. The increments related to the water use efficiency and instantaneous carboxylation efficiency allowed greater development of plants treated with thiamine. In addition, the application of thiamine is advantageous in cases where planting is carried out under conditions of low base saturation, followed by an adequate supply of nutrients or systems in which there is a partial or total correction of the soil chemical characteristics, promoting the development of plants and increased physiological activity.

The cultivation of beans (Phaseolus vulgaris L.) is of great importance to the national economy since they are grown in almost all regions of Brazil and the use of biostimulants based on phytohormones and plant vitamins can improve the yield of the crop. This work aimed to evaluate the effects of the application of the vitamin nicotinamide and phytohormones as biostimulants on bean plants. The experimental design was carried out in randomized blocks in a 2 x 5 factorial scheme with 4 replicates. The treatments consisted of the application of five doses of nicotinamide (0, 200, 400, 600 and 800 mg L^-1) in the presence or absence of phytohormones containing auxin, gibberellin and cytokinin. The growth characteristics, production components and productivity of the bean grains were evaluated. The use of phytohormones and nicotinamide alone or together favored the growth, production components and grain productivity of the bean plant. The range of 366 to 469 mL L^-1 nicotinamide achieved the highest values for the growth variables, production components and grain productivity of the bean plant, with 414 mL L^-1 being the most suitable to achieve higher grain productivity.

The expansion of eucalyptus cultivation to new areas with unfavourable environmental conditions can bring the risk of severe water stress at the beginning of seedling growth, which requires management or the use of agents that mitigate this condition. Therefore, the aim of this study was to evaluate the effects of silicon and biostimulant application on eucalyptus seedlings under water stress conditions. The experiment was installed in a randomized block design in a 5 x 2 factorial scheme, where five doses of silicon dioxide (SiO2 - 91%) incorporated into the substrate (0.0; 1.17; 2.33; 3.50 and 4.66 g L-1) were tested in the presence (20.0 mL L-1 water) or absence of Stimulate® biostimulant, with five replicates. The experiment was installed in 6.0 L-1 polyethylene bags under simulation of water stress in an open area. The combined application of silicon and biostimulant influenced stem diameter and root dry mass. The dry mass of the leaves and the total height of the seedlings were only influenced by the application of silicon. The SiO2 doses, which in combination with the biostimulant or not, provided higher values for the total height, stem diameter, dry mass of leave, stem and root parameters, ranged from 2.90 to 3.83 g SiO2 L-1. Both the occurrence and severity of water stress symptoms were modified by the application of silicon, combined or not combined with biostimulants. The isolated application of biostimulant and silicon at a dose of 4.66 g L-1 as well as the use of this dose in combination with biostimulant resulted in longer and less severe stress symptoms.