Drought is the most harmful environmental factor crop productivity. Some chemicals are used in agriculture to mitigate the damage from this stress on plants. Therefore, we examined whether the spraying of zinc sulfate (ZS), potassium phosphite (KPhi) and the hydrogen sulfide (H2S) donor sodium hydrosulfide (NaHS) would mitigate the deleterious effects of water deficit on sunflower plants by analyzing physiological and biometric characteristics. The experiment was carried out in a greenhouse using a randomized block design with five replications. The treatments were arranged in a 4 x 2 factorial scheme: [Factor A (Alleviators)] - spraying of KPhi (0.5 L ha-1), ZS (3.2 kg ha-1), NaHS (1.2 g ha-1), and water; [Factor B (substrate humidity, SH)] - 100% (well irrigated) and 30% (water deficit, WD) of field capacity. Under WD conditions, alleviators led to the maintenance of higher values of water potential (ΨW), a lower content of leaf malonaldehyde (MDA), and increased activity of the antioxidant enzyme peroxidase (POX), except for ZS. However, leaf osmotic potential, proline concentration, variables related to gas exchange and chlorophyll a fluorescence, and biometric characteristics differed only according to the SH factor. The results of ΨW and MDA for sunflower plants under WD are indicative of the mitigating capacity of ZS, KPhi, and H2S. Thus, the spraying of these compounds on sunflower plants mitigates the effects of WD, acting specifically in physiological processes related to antioxidant responses and in the maintenance of water in leaf tissues.

Thermal stress reduces plant growth and development, resulting in considerable economic losses in crops such as soybeans. Nitric oxide (NO) in plants is associated with tolerance to various abiotic stresses. Nevertheless, there are few studies of the range of observed effects of NO in modulating physiological and metabolic functions in soybean plants under high temperature. In the present study, we investigated the effects of sodium nitroprusside (SNP, NO donor), on anatomical, physiological, biochemical, and metabolic processes of soybean plants exposed to high temperature. Soybean plants were grown in soil: sand (2:1) substrate in acclimatized growth chambers. At developmental V3 stage, plants were exposed to two temperatures (25 °C and 40 °C) and SNP (0 and 100 μM), in a randomized block experimental design, with five replicates. After six days, we quantified NO concentration, leaf anatomy, gas exchange, chlorophyll a fluorescence, photosynthetic pigments, lipid peroxidation, antioxidant enzyme activity, and metabolite profiles. Higher NO concentration in soybean plants exposed to high temperature and SNP showed increased effective quantum yields of photosystem II (PSII) and photochemical dissipation, thereby maintaining the photosynthetic rate. Under high temperature, NO also promoted greater activity of ascorbate peroxidase and peroxidase activity, avoiding lipid peroxidation of cell membranes, in addition to regulating amino acid and organic compound levels. These results suggest that NO prevented damage caused by high temperature in soybean plants, illustrating the potential to mitigate thermal stress in cultivated plants.

Chemical ripeners are frequently used on sugarcane crops in order to increase profitability. However, the drift of these products to neighbouring fields can expose susceptible non-target plants, such as sunflower, to these agents causing indirect impacts on growth and development. Therefore, this study aimed to assess the toxicity characterize possible changes in the growth of sunflower plants exposed to simulated drift of the ripeners glyphosate and trinexapac-ethyl. For each ripener, the following doses were used: glyphosate (0 (control), 3.6, 7.2, 14.4, 28.8 and 86.4 g a.e ha-1) and trinexapac-ethyl (0, 3.12, 6.25, 12.50, 25 and 75 g a.i ha-1). The effects of these products on plant height, number of leaves, leaf area, stem diameter and dry matter (leaves, stem, flower, root, shoot and total) were evaluated. We also conducted a visual analysis of symptoms of phytotoxicity after exposure. The effects of the ripeners on sunflower plants varied depending on the type of agent used and the dose. Plants treated with glyphosate showed altered growth patterns, indicating high sensitivity of these plants to the herbicide. With increasing doses, glyphosate drift promoted lower growth and development of sunflower plants and negatively affected productivity. Nevertheless, trinexapac-ethyl drift, in the evaluated doses, did not affect sunflower plants.

O tomateiro para processamento industrial é uma hortaliça que movimenta o agronegócio brasileiro. Portanto, conhecer a dinâmica da produção agronômica e científica a respeito dessa cultura é de fundamental importância para traçar novas estratégias de cultivo e de comércio e, ainda, direcionar novos estudos para suprir as deficiências da cadeia produtiva brasileira. O objetivo do estudo foi reunir informações sobre características gerais da produção e dos híbridos de tomateiro para processamento industrial comercializados no Brasil e ainda realizar um levantamento cenciométrico da produção científica a respeito da cultura. Foi realizado um levantamento bibliográfico sobre a evolução da tomaticultura para processamento industrial no Brasil. Para avaliar a evolução da produção foi quantificado o número de empresas que comercializam sementes e características de híbridos comercializados no Brasil. Para conhecer o comportamento da pesquisa acerca do tema proposto, foi utilizada a base de dados Scopus sendo empregadas como termos de busca as palavras-chave: “tomato processing industrial” no período de 1969-2019. O Brasil é o maior produtor da cultura na América do Sul. Goiás é o Estado que mais cultiva a cultura, sendo os municípios de Cristalina, Itaberaí, Morrinhos, Piracanjuba e Vianópolis aqueles com destaque na produção. Onze empresas comercializam sementes no Brasil atualmente, a maioria com sede internacional. Os frutos apresentam massa entre 80 a 240 gramas e o ciclo da cultura varia de 90 a 120 dias após o transplantio; e ainda apresentam resistências a Fusarium spp., Verticilium spp. e Meloidogyne spp., principalmente. Nas últimas décadas, notou-se um crescimento da literatura em tomateiro para processamento industrial, sendo a Itália é o país que mais publica sobre o assunto. As subáreas Fitotecnia e Ciência dos Alimentos representam maior interesse dos pesquisadores. No Brasil, instituições de ensino e de pesquisa das regiões Centro-Oeste e Sudeste são as que mais se dedicam a esses estudos.

This study describes the evaluation of the effectiveness of different soil covers on the development, productivity, yield and metabolic content of patchouli oil (Pogostemon cablin) and its hydrolate. The agronomic experiments were carried out in the field, including four types of soil cover and six replications (4 x 6), using green cover (peanut), straw (crotalaria and millet straw), white plastic cover, and no mulch (weeding). After transplanting, the initial growth of seedlings was analyzed through weekly monitoring of plant height, stem diameter, and the number of leaves. At harvest time, the harvest yield (green mass) was performed. After drying the leaves, the oil and hydrolate were extracted by steam distillation and then the yield of patchouli oil was determined. Regarding the agronomic analyses, white plastic and straw coverage was superior to the other treatments, with higher plant heights, number of leaves, whereas the plastic and straw coverage was superior to the other treatments, with higher plant heights, number of leaves and green mass yield. The metabolic content was evaluated using High Resolution Mass Spectrometry (HRMS), and the chemical markers were identified through the analysis of the MS/MS fragmentation spectra and chemotaxonomic data. No significant differences were observed in the essential oils yields and their hydrolates and the intensities of the major ions found in the samples identified as chemical markers for the quality control of P. cablin.