Seed vigor and seedling growth directly impact the early stages of maize production. These traits might be improved with the use of bioinoculants. This work aimed to evaluate the influence of Bacillus sp. RZ2MS9 and its bacteria-free filtrate in the seeds germination rate (G) and speed (GSI) and seedlings length (SL) and dry mass (SDM) of two maize hybrids. After receiving experimental treatments, seeds of maize hybrids DKB390 and 30A37PW ® were grown in a germinator at 25 o C and 90% humidity. GSI was evaluated daily while G (%), SL (cm) and SDM (mg.10 seeds-1) were evaluated after 7 days. GSI and SDM were higher in both hybrids treated with Bacillus sp. RZ2MS9. The bacteria-free filtrate produced higher GSI in the 30A37PW ® hybrid only in comparison to the control treatments. Thus, the Bacillus sp. RZ2MS9 and its extracellular secreted compounds might comprise alternative tools to improve development and production of maize plants.

Productive efficiency and production costs are factors that impact the economic success of sugar and ethanol plants. Ethanol is a highly demanded product and, during the off-season period of sugarcane, its residual production is insufficient to supply the market. This generates the need for imports and adversely affects the Brazilian trade balance. In this context, the ethanol produced from corn figures as a potential alternative to ensure the market supply, generating revenue and diluting plants’ operational costs by expanding its operational period throughout the year. However, access to raw materials and implementation costs can affect the economic viability of this activity. In this study, the objective was to evaluate if the profitability of corn ethanol is feasible within the context of a sugarcane-only plant to be adapted to flex, located in the state of São Paulo. The increment in the marketing margin of this fuel and its co-products was used as an indicator, taking into account the difference between the costs of raw materials in two regions. The results demonstrate that the marketing margin of corn ethanol is negative in the state of São Paulo due to its distance from major corn supplies in Brazil. Although, when we considered the potential revenue from co-products, the loss scenario is converted into profitability. Thus, it is concluded that the profitability of the corn ethanol production in this scenario depends on the commercialization of its co-products in consumer markets, such as pig farming and biodiesel plants.

Biological agribusiness has grown substantially worldwide and requires efficient strategies to maintain or increase crop production. However, little is known about the real economic gains associated with belowground mechanisms in agriculture, including those of traditional crops such as sugarcane. This study aimed to identify potential microbiological indicators related to yield increase and value the soil microbiological services through the development of a structural equation model (SEM). The SEM was constructed based on a dataset from a previous sugarcane field experiment in which the effects of inoculation with phosphate-solubilizing bacteria (PSB) and the input of organomineral fertilizer were evaluated. The SEM indicated that the β-glucosidase and alkaline phosphatase activities were potential indicators of yield increases in four scenarios (current, plausible, optimistic, and futuristic). Increases of 158 and 195 t ha-1 were projected based on the β-glucosidase activity for the current and plausible scenarios, respectively. These increases resulted in economic gains of R$ 453.02 ha-1 (US$ 86.07 ha-1) for the current scenario, and R$ 1,571.53 ha-1 (US$ 298.59 ha-1) for the plausible scenario, considering the exchange rate from February 2022 (R$ 0.19 US$-1). Regardless of the scenario, bacterial inoculation was associated with increased β-glucosidase or alkaline phosphatase activity and higher yields, which translates into economic gains for sugarcane farmers.

Aluminium (Al) toxicity in acid soils is a major abiotic stress that can limit plant production worldwide. Al toxicity directly inhibits root development and exacerbates oxidative stress in the plant. Sugarcane is mostly cultivated in tropical regions and is often exposed to phytotoxic concentrations of soil Al. In this study, our objectives were to evaluate nine sugarcane cultivars on their tolerance to Al in a hydroponic system, investigating the effects of 143µM {Al3+} on root growth and on activity of the antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD). The screening method proposed was suitable for a rapid, reliable and reproducible procedure of the sugarcane cultivars. Exposure to Al for three days altered root growth and activity of enzymes of the nine sugarcane cultivars. However, the magnitude of the alterations varied significantly among cultivars. The cultivar RB928064 was classified as Al-tolerant and the cultivar RB835486 as Al-sensitive. Increases in enzyme activity after Al exposure varied from 4 to 46%, with average increases of 19% in APX, 20% in CAT, and 8% in SOD. The variations induced by Al in enzyme activity, however, did not correlate significantly with those variations induced by Al in the root growth.

O biodiesel é hoje um dos principais candidatos para a substituição do combustível obtido a partir dos derivados de petróleo já que estes, durante sua queima, apresentam grande potencial poluidor. Por ser um combustível renovável, biodegradável e com baixo teor de poluição, o biodiesel vem sendo estudado cada vez mais no campo de pesquisa, utilizando-se desde alimentos a óleos vegetais. Sua obtenção consiste na conversão de triglicerídeos a ésteres de ácidos graxos a partir do processo chamado de transesterificação. A transesterificação enzimática é um processo vantajoso por se obter uma melhor pureza do produto e, no final, se consegue reutilizar o biocatalisador. As lipases de Candida antarctica são amplamente utilizadas como biocatalisadores neste tipo de processo por apresentarem características favoráveis a obtenção do produto final (biodiesel). Como a região de Minas Gerais apresenta uma vasta produção de café, selecionou-se esta matéria-prima como principal fonte de obtenção do combustível que, futuramente pode ser usado em veículos próprios. Palavras-chave: biodiesel, óleo de café, óleo de soja, transesterificação e lipases.