Salt stress results in physiological changes that inhibit plant growth and development. Ca-complex sources are used as a potential salt stress attenuator. This study was carried out with the aim of verifying the effects of Ca-complex sources in reducing the effects of saline water stress on the physiological aspects of sour passion fruit seedlings. The experiment was carried out in a randomized block design with a 2 × 2 × 3 factorial scheme, consisting of two cultivars of sour passion fruit (BRS GA1 and BRS SC1), two levels of water salinity (electrical conductivity of 0.5 and 4.0 dS m⁻¹) and three sources of Ca-complex (without, organic acids and amino acids). The traits measured at 60 days after sowing were gas exchange, chlorophyll indices, chlorophyll fluorescence, electrolyte leakage, and relative water content in the leaf limb. Under moderate water salinity, the application of Ca-complex in amino acids promoted increases of 49.84% and 43.71%, respectively, in the efficiency of water use and carboxylation. The application of complex sources increased the stability of cell membranes, reducing electrolyte leakage, providing higher relative water content in seedlings irrigated with moderately saline water. From the results, we conclude that Ca-complex sources have potential as modulators of moderately saline water stress in sour passion fruit seedlings.

Pollen fertility is indicated by viability, which influences the reproductive success of plants. Mandacaru is a native tree species with natural distribution in the Caatinga. The objective was to verify the pollen viability, pollen per ovule ratio and the morphological identification of the mandacaru flower (Cereus jamacaru). Ten flower buds were used and one hundred anthers of these buds, which and stained with Alexander dye on checkered glass slide and viable and non-viable pollens were accounted amount of ovule per flower bud was counted the pollen/ovule ratio. Mandacaru presented viability of 99.41% the pollen, with an average of 314,686 pollens on each flower. There were 356 pollens for each ovule, this indicates the species reproductive system for facultative autogamous and facultative xenogamics. The flower is hermaphrodite, with gynoecium measuring an average of 160.9 mm, an average of 883 ovules per flower, the androecium averaging 577 anthers per flower, 545 pollen per anther. Mandacaru has high pollen viability, with large size hermaphrodite flower, with high number of anthers and pollen contained in these anthers.

A estrutura da vegetação na floresta tropical sazonalmente seca está sujeita a uma série de processos que desencadeiam mudanças significativas em seu ambiente, onde a família Cactaceae desempenha papéis múltiplos nesses ambientes. O estudo teve como objetivo verificar distribuição espacial e estrutura populacional de Tacinga inamoena em três ambientes diferentes na floresta tropical sazonalmente seca no Brasil. Três áreas de estudo foram identificadas, sendo a área I no município de Aroeiras, área II Bananeiras e a área III em São João do Cariri, cada uma localizada em diferentes microrregiões do estado da Paraíba, Brasil. Foram alocadas 10 parcelas de 400 m² cada. Foram calculados valores de estrutura horizontal, densidade absoluta, frequência absoluta e índice de agrupamento de Payandeh. Foram elaborados mapas de distribuição espacial da espécie para cada uma das áreas. A espécie apresentou maior densidade absoluta na área I, seguido pela área III e área II respectivamente. Em 100% das parcelas ocorreu a presença de T. inamoena nas três áreas de estudos, no entanto, essa distribuição não se apresentou uniforme. A espécie apresentou tendência ao não agrupamento nas três áreas analisadas. A presença de aglomerados contendo indivíduos da espécie, juntamente com bolsões vazios, foi observada nas três áreas. Torna-se imperativo implementar ações de monitoramento, proteção e aprofundamento dos estudos científicos relacionados à ocorrência e às ameaças enfrentadas pelas Cactaceae na floresta tropical sazonalmente seca.

O teste de tetrazólio avalia de forma rápida a viabilidade das sementes, cuja eficiência depende de ajustes metodológicos para cada espécie. Com isso, objetivou-se avaliar a viabilidade em sementes de Anadenanthera colubrina por meio desse teste. As sementes foram envelhecidas por 12 e 24 horas para obter diferenças na qualidade fisiológica. A qualidade inicial foi avaliada pelos testes de germinação; emergência; IVG e IVE; TMG e TME. Para o teste de tetrazólio utilizou-se o delineamento experimental inteiramente casualizado em esquema fatorial 3 x 9 e os tratamentos constaram: três condições de envelhecimento acelerado - EA (0, 12 e 24 h de EA) e nove combinações entre concentrações e tempo de imersão no sal de tetrazólio: 0,075%/4 h; 0,075%/6 h; 0,075%/8 h; 0,1%/4 h; 0,1%/6 h; 0,1%/8 h; 0,5%/4 h; 0,5%/6 h; 0,5%/8 h, com quatro repetições de 25 sementes, avaliados sob as temperaturas de 35 e 40 °C. As sementes foram classificadas em viáveis e vigorosas, viáveis e não vigorosas e inviáveis. O teste de tetrazólio foi eficiente para estimar a viabilidade de sementes de A. colubrina. Para isso, deve-se realizar o desponte na região oposta a micrópila, com pré-umedecimento em água por 10 h, seguido da remoção do tegumento e imersão na solução de tetrazólio a 0,1%, por 4 h, a 35 °C. Nessa condição, o teste de tetrazólio foi eficiente para identificar diferenças na qualidade fisiológica de sementes não envelhecidas e envelhecidas por 12 e 24 horas.

Salinity stress is one of the main limitations to the expansion of sour passion fruit areas in the semi-arid region of Brazil. Studies have shown that the application of calcium reduces the deleterious effects of salinity, especially when sources of rapid availability and absorption are used. The objective of this study was to evaluate the effect of complexed calcium sources on the growth and quality of sour passion fruit seedlings under salt stress. The experiment was conducted in a randomized block design, in a 2 × 2 × 3 factorial arrangement, relating to two sour passion fruit cultivars (BRS GA1 and BRS SC1), two levels of water salinity (0.5 and 4.0 dS m-1), and sources of complexed calcium (without calcium, complexed in organic acids, and complexed in amino acids). The following parameters were evaluated: height, stem diameter, root length, leaf area, dry mass (aerial part, root, and total), and Dickson's quality index. The results indicate that irrigation water with a salinity of 4.0 dS m-1 negatively affects the growth and quality of sour passion fruit seedlings, reducing plant height by 72.44% in BRS GA1 and 58.76% in BRS SC1 in the treatment without calcium. Under saline conditions, calcium complexed in organic acids showed more consistent mitigating effects, increasing total dry mass by 43.77% compared to the treatment without calcium. The use of calcium complexed with organic acids represents a promising strategy to mitigate salt stress during the seedling stage of sour passion fruit.

Industrial seed treatment protects soybean seeds against pests and diseases, but prolonged storage causes progressive physiological quality loss driven by phytotoxicity from neonicotinoid insecticides. To our knowledge, no prior research has evaluated whether stratified application, by applying components in ordered layers, reduces phytotoxicity while maintaining seed quality during storage. We evaluated 10 treatment processes combining fungicide, insecticides, polymer, and finishing powder in stratified or simultaneous sequences on soybean seed physiological quality, stored for 135 days at 20°C. A completely randomized 10 × 4 factorial design (10 processes × four storage periods: 0, 45, 90, and 135 days) with four replications was used. Physiological quality was assessed through germination in paper roll plus vermiculite, seedling emergence, accelerated aging, and modified accelerated aging in substrate. A phytotoxicity index was calculated for each test and analyzed via multivariate analysis and k-means clustering. Simultaneous application of all components (Mix) showed the highest phytotoxicity, reducing germination by 4 percentage points (pp) and vigor by up to 6 pp compared to stratified treatments. Treatments with fungicide in the first stage formed a low-phytotoxicity cluster, while Mix occupied an isolated high-phytotoxicity cluster. Seeds maintained viability for up to 90 days and vigor for up to 45 days under controlled storage. Stratified application, particularly with fungicide and polymer applied first, significantly reduces neonicotinoid phytotoxicity and represents a practical strategy to extend seed safety margins in the soybean seed production chain.