Cowpea is the main subsistence crop—protein source—for the Brazilian semi-arid region. The use of salt-stress-tolerant varieties can improve crop yields. We evaluated the effect of irrigation with brackish water on the growth, photosynthetic responses, production, and tolerance of fifteen traditional varieties of cowpea. The experiment was conducted in randomized blocks, in a 15 × 2 factorial scheme, composed of 15 traditional varieties of cowpea and two salinity levels of irrigation water (0.5 and 4.5 dS m⁻¹), with five replicates. Plants were grown in pots containing 10 dm³ of soil for 80 days. The reduction in the photosynthetic rate of cowpea varieties occurs mainly due to the decrease in stomatal conductance caused by salt stress. Salt stress increased the electron transport rate and photochemical quenching of cowpea varieties, but stress-tolerant varieties increased the CO₂ assimilation rate and instantaneous carboxylation efficiency. The Ceará, Costela de Vaca, Pingo de Ouro, Ovo de Peru, and Sempre Verde varieties are tolerant to salt stress. Salt stress decreases 26% of the production of tolerant varieties to salt stress and 54% of susceptible varieties. The present findings show the existence of variability for saline stress tolerance in traditional varieties of cowpea and that Ceará, Costela de Vaca, Pingo de Ouro, and Ovo de Peru varieties are more suitable for crops irrigated with saline water.

Biological control employs beneficial microorganisms to suppress phytopathogens and mitigate the incidence of associated plant diseases. This study investigated the in vitro development and survival of Trichoderma spp. isolates derived from commercial formulations under different temperatures, pH levels, and sodium chloride (NaCl) concentrations and with synthetic fungicides with distinct modes of action. Three isolates were analyzed: URM-5911 and TRA-0048 (T. asperellum) and TRL-0102 (T. longibrachiatum). The results revealed substantial variability among the isolates, with the optimal mycelial growth temperatures ranging from 24.56 to 29.42 °C. All the isolates exhibited broad tolerance to the tested pH (5–9) and salinity levels (250–1000 mM), with TRL-0102 demonstrating the highest salt resistance. The fungicide treatments negatively affected mycelial growth across all the isolates, with Azoxystrobin + Difenoconazole and Boscalid causing growth reductions of up to 50%. Notably, Boscalid enhanced conidial production more compared to the control (126.0% for URM-5911, 13.7% for TRA-0048, and 148.5% for TRL-0102) and decreased the percentage of inactive conidia to less than 10% in all the isolates. These results provide strategic information for the application of Trichoderma spp. in agricultural systems, supporting the selection of more adapted and suitable isolates for integrated disease management programs.

Purslane (Portulaca umbraticola Kunth) is used as a food, medicinal, and ornamental plant. Its ornamental use is associated with the wide genetic variability in phenotypic traits, which is fundamental in breeding programs. The objective of this study was to select parents of P. umbraticola Kunth, based on genetic divergence of ornamental purposes. Twenty-two accessions were collected in the states of Ceará, Rio Grande do Norte, and Paraíba, Brazil. The experiment was conducted in a completely randomized design, with twenty-two treatments and three replicates. Plants were evaluated 40 days after planting, at full bloom. The evaluated traits were: plant height, stem diameter, crown diameter, leaf length, leaf width, flower diameter, petal length, number of flowers per plant, chlorophyll a, and chlorophyll b, and flower color. Data were subjected to analysis of variance and Scott-Knott test (p ≤ 0.05). Heritability and the ratio between coefficient of genetic variation and coefficient of environmental variation were estimated. The genotypes were grouped by Tocher’s method, and the importance of traits by Singh’s method. The accessions were grouped into seven clusters, demonstrating genetic variability, with greater importance of the traits crown diameter, plant height, and number of flowers per plant. Eight phenotypic classes were found for flower color, demonstrating the potential of these accessions for use in breeding programs. Based on intergroup distance and considering the key traits for ornamental purposes, the accessions Ac2, Ac4, Ac6, Ac16, Ac18, and Ac19 should be selected as parents. The use of selection index should improve the choice of the parents.