Advanced oxidative processes (AOPs) are procedures used for the treatment of wastewater based on the generation of free radicals, such as hydroxyl (•OH) and carbonate anion (CO₃^•−) radicals. However, although contaminants are degraded in these processes, the by-products generated in this transformation can be a greater source of toxicity than the original compound, making ecotoxicological tests essential for monitoring the efficacy of these treatment processes. In this study, we examined the ecotoxicity of AOP by-products generated using peracetic acid (PAA) and sodium carbonate, with and without solar radiation, for the degradation of methylene blue dye, using the planarian Girardia tigrina as a test organism. Ecotoxicological tests evaluated the acute toxicity of the generated by-product in terms of lethal concentrations (LC₅₀). Although in both assays the degradation of the dye was greater than 99%, higher toxicity was observed in the assay using PAA and carbonate in the absence of radiation. From the results obtained, we conclude that the by-product generated from the degradation of methylene blue dye by peracetic acid and sodium carbonate, with and without solar radiation, can pose risks to aquatic ecosystems if released directly into water bodies.

Objetivou-se determinar a taxa de transporte de população de fungos associados às sementes de pinhão manso, a patogenicidade desses microrganismos a plântulas e frutos e a transmissibilidade fruto-semente e semente-plântula. Avaliaram-se a taxa de transporte, por meio de blotter test, de sementes produzidas nos estados de Minas Gerais, São Paulo, Bahia e Tocantins. As sementes foram submetidas aos tratamentos: sem desinfestação com tegumento (SDCT), sem desinfestação sem tegumento (SDST), com desinfestação com tegumento (CDCT) e com desinfestação sem tegumento (CDST). A incidência (%) dos fungos foi avaliada sob microscópio estereoscópico binocular. Para o teste de patogenicidade em plântulas e frutos inocularam-se suspensões de 10(6) esporos e discos de BDA com micélio, respectivamente. Para os fungos fitopatogênicos avaliaram-se a transmissibilidade fruto-semente e semente-plântula. O tratamento SDCT permitiu a detecção de maior número de fungos. Os fungos identificados foram Colletotrichum gloeosporioides, C. capsici, Curvularia sp., Verticillium sp., Fusarium sp., Penicillium sp., Aspergillus sp., A. niger e Rhizopus sp. Apenas as espécies de Colletotrichum são patogênicas às plântulas e frutos. Para ambas espécies há transmissibilidade fruto-semente, entretanto não é observada transmissão semente-plântula.

The objective was to evaluate the response of lettuce seedlings to foliar application of different sources and doses of zinc. The experiment was carried out in a greenhouse, and the design was completely randomized in a factorial scheme (3 x 5), consisting of 3 sources with 5 doses each: Zn sulfate (0, 50, 100, 150 and 200 g Zn ha-1), Zn oxide (0, 187, 375, 562 and 750 g Zn ha-1) and Zn chelate (0; 36.25; 72,50; 108,40; and 145 g Zn ha-1), with 4 repetitions. The highest levels of foliar Zn were obtained at doses of 200, 562 and 72,50 g Zn ha-1, from sulfate, oxide and chelate sources, respectively.

Onion is one of the most widely consumed seasoning vegetables in the world. Beyond productivity, onion quality is of great importance, influenced by factors such as appearance, aroma, flavor, and chemical composition. This study aimed to evaluate the effect of applying elemental sulfur at different growth stages on the postharvest quality attributes of onion bulbs. Two experiments were conducted at different times using a factorial design in randomized blocks. Four hybrids were tested: Diamantina®, Optima® F1, Serena® F1, and Gamay® F1 (purple). The second factor was the timing of foliar elemental sulfur application: at the development stages of 4–6 leaves, 6–8 leaves, 8–10 leaves, and 10–12 leaves, along with a control group that received solid elemental sulfur applied to the soil. The evaluated attributes included pungency (µmol.g-1), soluble solids (°Brix), total titratable acidity (% pyruvic acid), pH, leaf sulfur content, and bulb sulfur content. Among the traits measured, the pyruvic acid content was influenced by the timing of sulfur application, with the Serena® F1 hybrid at the 10–12 leaf stage showing significant differences from the other hybrids. Regarding pungency, the Diamantina®, Serena® F1, and Gamay® F1 hybrids were classified as having medium pungency when sulfur was applied foliarly, while the Optima® F1 hybrid was classified as low/sweet pungency. Sulfur content in the bulbs and leaves of the onion cultivars was not significantly affected by foliar sulfur application.