This study aimed to evaluate the effect of stress attenuators on the tolerance and antioxidant activity of watermelon cultivars under water deficit. The experiment was conducted in two stages, Stage I corresponding to water deficit levels (N1 = 0; N2 = −0.1; N3 = −0.2 MPa) and six watermelon cultivars. Stage II comprises two cultivars selected in Stage I (one sensitive and one tolerant) and the combination of water restriction with attenuators (T1 = 0.0 MPa (control), T2 = −0.2 MPa (water deficit), T3 = −0.2 MPa + hydropriming, T4 = −0.2 MPa + gibberellic acid, T5 = −0.2 MPa + salicylic acid, and T6 = −0.2 MPa + hydrogen peroxide). The concentration and exposure times of the attenuators were determined through preliminary tests. In Stage I, physiological and biochemical analyses were performed. In Stage II, in addition to these tests, hydrogen peroxide content, malondialdehyde levels, and the activity of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) were assessed. Water deficit impaired germination and seedling vigor of watermelon, with Crimson Sweet, Omaru, Charleston Gray, and Congo being the most sensitive cultivars, while Fairfax was the most tolerant. For Crimson Sweet, pre-germination treatments reduced oxidative stress and enhanced tolerance by stimulating antioxidant enzyme activity, with GA and H₂O₂ providing the most effective results. For Fairfax, greater tolerance was associated with osmotic adjustment through the accumulation of compatible solutes, a mechanism further enhanced by the use of attenuators.

Erythrina velutina Willd. is a xerophytic plant native to the Caatinga, whose seeds show heteromorphism in seed coat color, varying between reddish and orangish. This study aims to analyze the influence of seed coat color on the physical characteristics, dormancy and physiological potential of the seeds of this species. The seeds were evaluated for length, width, moisture content, hundred-seed weight, water absorption curve, first count, germination, hard seeds, shoot and root length, and shoot and root dry mass. In addition, cross-sectional fragments of 10 seeds of each color were examined by means of a scanning electron microscope (SEM), which was used to visualize the epidermis, palisade layer and parenchyma cell layers. The experimental design was completely randomized with four replications of 25 seeds in a 2 x 2 factorial scheme, considering seed coat color (orangish and reddish) and dormancy overcoming (intact and scarified seeds). The data were subjected to analysis of variance and compared by Tukey test at 5% probability level. There was no significant influence of seed coat color on the physical characterization of the seeds. It was found that reddish seeds have greater dormancy and lower physiological potential when compared to orangish seeds.

Sugarcane plays an important role in the agricultural economy of Pedras de Fogo, Paraíba, contributing to the economy in terms of generating jobs and income in the region. However, its production has been affected by challenges such as climate variations and traditional agricultural practices. The objective of this study was to analyze the productive dynamics of sugarcane in the municipality of Pedras de Fogo, PB, between 2004 and 2023, seeking to understand the factors that influence this production chain and offer subsidies for local development actions. The methodology consisted of analysis through a database, evaluating the variables: planted area, harvested area, quantity produced, productivity and production value. The results revealed a significant reduction in the cultivated area, which went from approximately 30.000 hectares (ha), in 2004 to approximately 18.000 ha in 2023, with emphasis on 2019, which presented the lowest production. Despite the reduction in area, a trend towards increased production was observed, reflected in the stability of productivity throughout much of the period. Therefore, to ensure the sustainability of the activity, it is necessary to invest in more efficient agricultural practices, adoption of technologies, adequate irrigation management and strengthening of public policies that support local producers.

Salinity compromises seed germination and early seedling growth, highlighting the need to identify tolerant cultivars and effective management strategies. This study aimed to evaluate tolerance to salt stress, antioxidant activity, and the effectiveness of seed-applied stress attenuators in pumpkin cultivars. The research was conducted in two stages. In the first stage, six cultivars (Tetsukabuto, Soberana, Kin, Bahiana Tropical, Sergipana, and Adele) were subjected to three levels of osmotic potential induced by NaCl (0.0, −0.2, and −0.4 MPa). Germination, growth, and biochemical variables were evaluated. In the second stage, two contrasting cultivars were subjected to six treatments: control (0.0 MPa), salt stress (−0.4 MPa), hydropriming, gibberellic acid, ascorbic acid, and salicylic acid, all under salt stress (−0.4 MPa). In addition to germination and growth variables, oxidative damage (H₂O₂ and lipid peroxidation) and antioxidant activity (SOD, CAT, and APX) were evaluated. Salt stress significantly reduced germination, growth, and biomass accumulation. Cultivar Adele showed greater tolerance, whereas Tetsukabuto was more sensitive. Hydropriming, gibberellic acid, ascorbic acid, and salicylic acid mitigated the effects of salinity, with hydropriming showing the greatest reduction in lipid peroxidation. It is concluded that Adele, combined with gibberellic acid, and Tetsukabuto, combined with hydropriming and gibberellic acid, showed better performance under salinity stress, highlighting the potential of physiological and biochemical traits for identifying contrasting responses to salinity.

Among the main factors affecting maize (Zea mays L.) productivity, water scarcity stands out, especially during the early stages of development. This study aimed to evaluate the tolerance of maize cultivars subjected to water deficit conditions during germination and early seedling growth. The experiment followed a completely randomized design in a 20 × 3 factorial arrangement, consisting of twenty maize cultivars (‘BRS 2022’, ‘BRS 4103’, ‘BRS Cruzeta’, ‘BRS Gorutuba’, ‘Capo 22’, ‘HTC697’, ‘HTC717’, ‘HTC795’, ‘MC 70’, ‘PF 7008’, ‘Potiguar, Sintético 91801587’, ‘Sintético 91801590’, ‘Sintético 91801592’, ‘Sintético 91801596’, ‘Sintético 91801599’, ‘Sintético 91801600’, ‘Sintético 91801601’, ‘Sintético PESAGRO-RIO’, and ‘UFLA JM100 POP AXB’) and three polyethylene glycol (PEG-6000) concentrations at water potentials of 0.0, −0.2, and −0.4 MPa to simulate water deficit. The analyzed variables included germination, first germination count, germination speed index, shoot and root length, root volume, shoot and root fresh and dry mass, and electrolyte leakage. Water deficit reduced germination and vigor in the maize cultivars. The potential of -0.4 MPa had a significant impact on shoot length and shoot fresh mass of the cultivars, causing mean reductions 75%. The cultivars ‘BRS 2022’, ‘UFLA JM100 POP AXB’, ‘Sintético PESAGRO-RIO’, ‘PF 7008’, ‘HTC697’, ‘BRS Gorutuba’, ‘Sintético 91801596’, ‘MC 70’, ‘Capo 22’, ‘BRS Cruzeta’, and ‘Potiguar’ were the most tolerant at −0.2 and −0.4 MPa. The cultivars ‘HTC717’, ‘HTC795’, ‘Sintético 91801587’, ‘Sintético 91801590’, ‘Sintético 91801599’, and ‘Sintético 91801600’ were the most sensitive under more severe water deficit conditions (−0.4 MPa).

Pumpkin (Cucurbita spp.) is a vegetable of great socioeconomic importance for the Brazilian semi-arid region, but its production faces challenges due to adverse edaphoclimatic conditions. Environmental stresses, such as water deficit, are limiting factors during seed germination and plant establishment. Therefore, this study aimed to select pumpkin cultivars that are more resistant when subjected to water deficit. The experiment was conducted in a completely randomized design, with four replicates of 25 seeds, in a 3 × 6 factorial scheme, combining three levels of water deficit (0.0, -0.15, and -0.3 MPa of polyethylene glycol, PEG 6000) and six Cucurbita spp. cultivars, including five pumpkin cultivars (“Tetsukabuto”, “Soberana”, “Kin”, “Bahiana Tropical”, and “Sergipana”) and one zucchini cultivar (“Adele”). The evaluated variables included germination, germination speed index, shoot and root length, shoot and root dry mass, total free amino acids, proline, total soluble sugars, and citrulline. The data were analyzed and subjected to cluster analysis and variance analysis compared by the Scott-Knott test (P ≤ 0.05). Water deficits of -0.15 and -0.3 MPa affect the initial growth of pumpkin cultivars, with negative impacts on germination, growth, biomass accumulation, and cellular osmotic homeostasis. The “Adele” cultivar stands out as the most tolerant to the -0.15 MPa water deficit, while “Tetsukabuto” is the most sensitive. Water deficit tolerance in pumpkins is related to the ability to accumulate metabolites such as proline, soluble sugars, and amino acids.