ABSTRACT Semen cryopreservation is essential for the conservation and maintenance of germplasm stocks from several species, each of which has specific requirements for successful cryopreservation. The objective of this study was to develop a sperm preservation protocol for Prochilodus lineatus (curimba) using the sugars trehalose, sucrose, lactose, and raffinose. Because synergy among cryoprotectants is not always beneficial, each cryoprotectant was tested separately at three concentrations (50, 100, and 150 mM), and dimethyl sulfoxide (DMSO) was used as the control. After thawing, sperm kinetic parameters were analyzed using computer-assisted sperm analysis (CASA), and cellular functional parameters were assessed by flow cytometry. In the sperm kinetic analyses, only the amplitude of lateral head displacement did not differ statistically from the control (p > 0.05), whereas the other parameters were lower than those of the control. In the motility-period analysis, 100 mM trehalose was superior to the control (p < 0.05), supporting its use in the protocol. However, the results for the different parameters analyzed showed that the other sugars tested were not superior to the control (10% DMSO), indicating that they were not effective for cryopreservation. Trehalose at 100 mM showed the most favorable response among the tested sugars for P. lineatus sperm cryopreservation.
ABSTRACT Among the environmental factors influencing plant development, light is one of the most critical, directly affecting growth and physiological processes. Fluctuations in light intensity can significantly alter plant physiological mechanisms. This study aimed to evaluate the effects of different photosynthetically active radiation flux densities (PPFD) on the physiological responses of desert rose throughout the day. The experimental design was completely randomized, with treatments consisting of 18 photosynthetic photon flux densities (0, 25, 50, 75, 100, 125, 150, 175, 200, 400, 600, 800, 1,000, 1,200, 1,400, 1,600, 1,800, and 2,000 μmol m⁻2 s⁻1) and three evaluations throughout the day (8 a.m., 12 p.m., and 4 p.m.). Variations in gas exchange were analyzed, as were the flux densities that promote greater chlorophyll fluorescence and electron transport rate in desert rose plants. The results showed that physiological processes varied significantly with PPFD throughout the day. At 12 p.m., a PPFD between 1800 and 2000 μmol m⁻2 s⁻1 favored the highest rates of CO₂ assimilation, stomatal conductance and transpiration. Chlorophyll fluorescence, especially maximum and variable, was also increased under high irradiance, while initial fluorescence was higher under low light availability. The results highlighted the influence of photon flux on photosynthetic efficiency, gas exchange and fluorescence parameters, demonstrating the importance of times of the day in CO₂ assimilation and stomatal opening.
ABSTRACT The species Physalis angulata, belonging to the Solanaceae family, has potential growth in the berry market and pharmaceutical industry. However, technical information about its production cycle is still limited. This study aimed to fit and compare the Logistic and Gompertz nonlinear regression models to identify which one best describes the biological relationship between fruit production and seedling nursery time. The experiment was carried out in a completely randomized design, consisting of five periods of permanence of the seedlings in the nursery (22, 26, 30, 34 and 38 days), each treatment with five replicates and 12 plants per replicate. After transplanting, the plants were evaluated weekly for up to 70 days for survival, height, stem diameter and yield. Autoregressive logistic and logistic models showed better performance in fitting to the data of growth in height and stem diameter of P. angulata L. seedlings. According to parameter “c”, seedlings that remained for 34 days in the nursery showed faster growth in the field for both height and diameter. Seedlings that remained in the nursery for 38 days had higher fruit production compared to those of younger ages.
ABSTRACT Water deficit associated with salt stress can affect maize (Zea mays L.) yield. In this context, the objective of this study was to evaluate the yield aspects of maize irrigated with lowerand higher-salinity water and under suppression intervals. The experiment was carried out at the Piroás Experimental Farm, Redenção, Ceará, Brazil. The experimental design used was randomized blocks, in a 2 x 4 factorial arrangement, with the first factor being two levels of electrical conductivity of the irrigation water (0.8 and 3.0 dS m-1) and the second factor being four suppression intervals (NS: no suppression intervals; SI10 = suppression intervals from 40 to 55 DAS (V10 to V14); SI15 = suppression intervals from 50 to 65 DAS (R1); and SI20 = suppression intervals from 65 to 80 DAS (R2 to R4)), with four replicates. The following variables were evaluated: unhusked ear mass, husked ear mass, 1000-grain mass, number of grains per row, ear diameter, ear length, and yield. Salt stress negatively affects unhusked and husked ear mass, number of grains per row and ear length. Suppression intervals SI10, SI15, and SI20 had a negative effect on unhusked and husked ear mass, number of grains per row, and ear length. Salt stress and suppression intervals SI10, SI15 and SI20 negatively affected maize performance in terms of 1000-grain mass and yield.
ABSTRACT Growing interest in renewable products has driven research on the development of structural composites reinforced with plant-based fibers. Among their potential applications, thermal and acoustic insulation in civil construction stands out. This study aimed to evaluate the performance of sandwich panels manufactured with Pinus oocarpa veneers and luffa sponge. Three treatments were evaluated, consisting of five-layer panels that varied in the number of luffa sponge layers in the core (0, 1, and 2). The panels were assessed for physical properties (moisture content and density), mechanical properties (modulus of elasticity and modulus of rupture), as well as acoustic and thermal insulation performance. Analysis of variance was performed, and when statistically significant differences were detected, the Scott-Knott mean comparison test (5%) was applied. The results indicated that panels manufactured with two luffa layers exhibited lower sound absorption at frequencies between 200 and 1000 Hz, meeting acoustic comfort standards at 1000 Hz. Control panels, without a luffa core layer, showed higher mechanical strength. In addition, despite differences in thermal performance, all treatments met regulatory requirements and qualified as thermal insulators. Overall, sandwich panels manufactured with Pinus oocarpa veneers and a luffa core show promise for acoustic insulation and thermal comfort applications in civil construction, representing a natural and sustainable fibrous alternative.
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 & times; 2 & times; 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.
The characterization of genetic diversity in wild Passiflora species is essential to support conservation and breeding programs, allowing the identification of divergent and promising genotypes. The present study aimed to evaluate the genetic diversity within a half-sibling family of Passiflora morifolia Mast. using RAPD markers. The experiment was conducted in a greenhouse at the Laboratory of Biotechnology and Plant Breeding, Department of BioScience, Center of Agricultural Sciences, Federal University of Paraiba, in Areia, PB, Brazil. A total of 22 individuals from a half-sibling family of the wild species P. morifolia were evaluated. Young leaves were collected for genomic DNA extraction using the cetyltrimethylammonium bromide (CTAB) method. The samples were quantified on 0.8% agarose gel and, after purification with RNase and proteinase K, RAPD assays were performed using 14 primers. The presence and absence of bands were coded as 1 and 0, respectively, generating a binary matrix used to estimate genetic distances among accessions based on the complement of Jaccard similarity coefficient. Based on this matrix, a dendrogram was constructed using Ward's hierarchical clustering method. RAPD reactions amplified 895 fragments, of which 96.7% were polymorphic, indicating considerable genetic variability among the 22 individuals of the P. morifolia half-sibling family. The results indicate the potential use of these accessions in breeding and conservation programs for the species, with accessions 6 and 22 being the most genetically divergent.
priming with physiological regulators increases crop tolerance to salt stress. However, the use of non-enzymatic antioxidants, such as ascorbic acid (AsA), in fruit species remains under-researched, particularly during the germination and initial growth stages the most sensitive periods to salinity. This study aimed to evaluate seed priming with ascorbic acid as a mitigator of salt stress in the germination and initial growth of 'Paluma' guava. The experiment followed a completely randomized design in a 5 x 5 factorial arrangement, consisting of five levels of water electrical conductivity (ECw: 0.3, 1.3, 2.3, 3.3, and 4.3 dS m-1) and five ascorbic acid concentrations (0, 1.5, 2.0, 2.5, and 3.0 mM L-1). Salinity above 1.0 dS m-1 impairs the germination and initial growth of'Paluma' guava. Seed priming with 1.5 mM L-1 AsA resulted in the highest germination (91.1%) under an ECw of 0.81 dS m-1, maintaining germination above 80% up to an ECw of 2.69 dS m-1. Seedling growth and vigor were stimulated by priming under low-salinity conditions. AsA represents a viable alternative to mitigate the impact of salt stress under semi-arid conditions.
calcareum, a marine alga, can be used as a low-cost and eco-friendly tool to improve soil conditions, thereby enhancing crop development and meeting calcium requirements of plants grown in acidic soils. In this sense, the present study evaluated effects of different application rates, formulations, and application intervals of L. calcareum on development of watermelon plants, Citrullus lanatus cv. 'Crimson Sweet.' Two experiments were conducted in a completely randomized design. The first experiment evaluated different formulations and application rates of L. calcareum: micronized powder (MP: 50 Kg ha(-1)), concentrated suspension (CS: 10 L ha(-1), 20 L ha(-1), and 30 L ha(-1)), and nanoparticles (1 Kg ha(-1), 5 Kg ha(-1), and 10 Kg ha(-1)). In the second experiment, MP, CS, and nanoparticle formulations were assessed under three application intervals (7+7+7+7, 10+10+10, and 14+14 days). Results indicated that application of 5 L ha(-1) increased shoot length, which was 45% higher than control. Moreover, Nano formulation (1 kg ha(-1)) promoted the best root system performance, showing root dry mass three times greater than control. In the second experiment, seven-day application intervals associated with Nano formulation provided the largest increase in root dry mass (0.42 g). In conclusion, the use of L. calcareum nanoparticles applied at 1 kg ha(-1) and 7-day intervals represents the most efficient strategy to optimize watermelon root development, constituting a viable tool for organic production systems.
This study aimed to characterize the population dynamics and temporal variation of Zaprionus indianus and Zaprionus tuberculatus (Diptera: Drosophilidae) in guava orchards located in the semi-arid region of Paraiba, Brazil, evaluating their potential as agricultural pests. Sampling was conducted between August 2021 and July 2022 in two areas: the UFPB Experimental Station (S & atilde;o Jo & atilde;o do Cariri) and the Fazenda Almas Private Natural Heritage Reserve. The methodology included monthly collection of ripe guava fruits, standardized exposure of fruits in plastic trays in the orchards, and monitoring of adults using PET bottle traps containing molasses or hydrolyzed protein. Infestation indices (pupae/fruit and pupae/kg), pupal viability, and the FTD index (flies per trap per day) were estimated. The results revealed higher infestation and abundance of Zaprionus at Fazenda Almas, where the FTD index reached values above 3.5 in some months, exceeding the action threshold (0.5). In S & atilde;o Jo & atilde;o do Cariri, the indices were considerably lower. Both species were recorded at Fazenda Almas, whereas only Z. indianus was observed in S & atilde;o Jo & atilde;o do Cariri. Incidence occurred during the rainy season, although no statistically significant correlation was observed with climatic variables. The results reinforce the invasive and agricultural potential of these species in the Brazilian semi-arid region, indicating the need for continuous monitoring and the development of management strategies focused on regional fruit production.
Long-term experiments combining tillage systems and cover crops are essential to understand variation in soil physical and chemical properties under different environmental conditions, but data from Brazilian tropical Ultisols under conservation management remain scarce. This study evaluated the effects of conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), associated with different cover crops, on the physical and chemical properties of a Typic Hapludult. The experiment, conducted since 2001 at the Rural Campus Experimental Station of Universidade Federal de Sergipe, was cropped with maize (Zea mays) under the three tillage systems, each combined with sunn hemp (Crotalaria juncea), pearl millet, pigeon pea, and cowpea. Soil samples were collected from the 0.00-0.10 and 0.10-0.20 m layers. Soil bulk density in the 0.00-0.10 m layer was significantly higher under NT than under the other tillage systems, indicating surface consolidation under the absence of soil disturbance. Conservation tillage systems, particularly MT and NT, showed higher soil organic matter contents in the surface layer, and in both layers NT resulted in significantly higher soil organic matter content than CT and significantly higher soil carbon stocks than those observed under CT and MT. Among the cover crops evaluated, sunn hemp exhibited the greatest potential for soil organic matter increase. The results suggest that conservation tillage systems, especially when integrated with leguminous cover crops, may increase soil carbon stocks and contribute to improved soil quality in tropical Ultisols under continuous maize cropping.
Macrophomina phaseolina is a soil-borne fungal pathogen responsible for root rot and vine decline in melons. To develop effective control strategies, it is essential to understand the pathogen's genetic diversity. This study aimed to characterize the genetic diversity of M. phaseolina isolates and evaluate the effectiveness of Cymbopogon flexuosus (lemongrass) essential oil as a control agent. DNA from 30 isolates was extracted and analyzed using 13 RAPD markers, which generated 135 polymorphic bands (71.85% polymorphism). Genetic similarity among isolates ranged from 0.23 to 0.92. To test the antifungal potential of C. flexuosus oil, two specific isolates (CMM-4739 and CMM-4762) were treated with six oil concentrations (0.02, 0.05, 0.10, 0.15, 0.20, and 0.25%). A negative control (PDA medium) and a positive control (Maxim fungicide) were included. Colony diameter was measured daily in two perpendicular directions; the control treatment reached the edge of the Petri dish within three days. Results showed that a concentration of 0.15% resulted in the complete in vitro growth inhibition of both isolates. No significant difference in oil efficacy was observed between the two isolates. This study concludes that RAPD markers are suitable for assessing the genetic diversity of M. phaseolina and that C. flexuosus essential oil is highly effective at inhibiting fungal growth in vitro. These findings suggest that C. flexuosus oil holds significant potential for future in vivo management of the M. phaseolina-melon pathosystem.
Combining phosphorus fertilization and a conservationist soybean cultivation system favors the production of seeds with a high physiological and sanitary quality. Thus, this study evaluated the physiological and sanitary quality of soybean seeds from plants fertilized with different phosphorus sources and grown under different crop succession systems in the Cerrado of Maranhao, Brazil. The experiment was set up in a randomized block design and organized in a split-plot scheme with three replicates. In the plots, the presence or absence of cover with Urochloa ruziziensis (Syn. Brachiaria ruziziensis) was evaluated, and the subplots were composed of different phosphorus fertilizer sources: organomineral 1 (O1), organomineral 2 (O2), simple superphosphate (SSP), and the control (not fertilized with phosphorus). The following seed variables were analyzed: moisture content, emergence, emergence speed index, total dry phytomass, germination, accelerated aging, electrical conductivity, and seed health. The succession system with U. ruziziensis and SSP fertilization resulted in the best soybean performance in the Cerrado of Maranhao with a higher physiological and sanitary seed quality. O1 and O2 also yielded satisfactory results, positively contributing to seed vigor and health but slightly less so than SSP.
Watermelon is an important crop in the Northeast region of Brazil; therefore, the development of lines and cultivars adapted to the edaphoclimatic conditions of this region and to agroecological production systems is essential for farmers and the environment. This study estimated general combining ability (GCA) and specific combining ability (SCA), as well as their reciprocal effects, for earliness and for yield and fruit traits in watermelon genotypes. The experiments were conducted at the Universidade Federal do Vale do S & atilde;o Francisco (UNIVASF), in Petrolina, PE, Brazil, during two evaluation cycles. A randomized block design was used, with 19 treatments, three replications, and plots containing five plants. The data were subjected to analysis of variance and diallel analysis. Non-additive gene effects predominated for 58.8% of the variables. The GCA analysis showed that the parents BGH-UNIVASF 177 and BGH-UNIVASF 67 were the most promising for obtaining hybrids with higher marketable fruit yield and greater fruit weight. The parent 'Sugar Baby' was identified as a good combiner for earliness, fruit diameter, and soluble solids content. The parent BGH-UNIVASF 189 was identified as a good combiner for total fruit yield and soluble solids content. Hybrid 3 & times;4 was the most promising for the greatest number of agronomically important traits. Hybrids 1 & times;2, 1 & times;4, and 2 & times;4 were promising for earliness, soluble solids content, fruit yield, good vegetative development, and lower fruit weight. No reciprocal effects were found for the traits evaluated.
Tomatoes are the second most cultivated vegetable in Brazil. Despite their importance, nematodes of the genus Meloidogyne can compromise their productivity. Some bacteria have potential for managing these pathogens. Three experiments were carried out, each repeated once. In experiment 1, the efficiency of 20 bacterial isolates obtained from biofertilizers in the mortality of second-stage juveniles (J2) of M. exigua was evaluated. Bacterial isolates B-74,B- B-86, B-88,B- and B-121 were as efficient as Fluensulfona, with mortality probabilities of up to 82%. Experiment 2 was carried out to verify the compatibility between the seven most promising isolates evaluated in experiment 1. There was no antagonistic effect between the isolates, and they were identified as follows: B-74: Bacillus thuringiensis; B-75: Bacillus wiedmannii; B-84: Bacillus cereus; B85: Micrococcus luteus; B86: Bacillus cereus; B-88: Bacillus thuringiensis and B-121: Brevibacterium epidermidis. In experiment 3, the effect of the bacterial isolates selected in experiment 2, applied individually or in combination, on the biocontrol of M. exigua parasitizing tomato plants was evaluated. All treatments reduced the population of M. exigua, with the best results obtained by Fluensulfona and isolate B-121. There are no reports in the literature on the role of B. epidermidis as a biocontrol agent for M. exigua. It is concluded that isolates B-74, B-86, B-88, and B-121 are promising in the biocontrol of M. exigua and can be applied together, as there is no antagonistic effect between them.
[Vigna unguiculata (L.) Walp] is widely cultivated in Brazil, with diverse genotypes, which make it adaptable to different production systems and cultivation purposes, whether for grain or pod production. The objective of this study was to evaluate the genetic diversity of cowpea genotypes based on phenotypic traits for green pod production in southern Tocantins, Brazil. Two experiments were conducted, in Gurupi, Tocantins, and in Dian & oacute;polis, Tocantins. Twenty cowpea genotypes were evaluated using a randomized complete block design with four repetitions. The following traits were evaluated: pod length and width, number of grains per pod, number of pods per plant, weight of 100 green grains, wet and dry weight of 15 pods, pod moisture content, and green pod yield. The experimental data were subjected to analysis of variance, principal component analysis, Pearson's linear correlation analysis, path analysis, and cluster analysis. Green pod yield was the trait that contributed the most to the total variability observed in the study. Correlation analysis and path analysis demonstrated that green pod yield was most directly affected by the number of pods per plant and wet pod weight. Cluster analysis based on the Mahalanobis distance matrix formed four distinct groups. The genotypes MNC11-1013E-16, MNC11-1019E-8, MNC11-1020E-16, MNC11-1026E-15 and MNC11-1026E-19 stood out with the highest green pod yield values.
Semi-arid regions face problems such as water deficit and salt accumulation in the soil, which compromise the physiological performance and growth of crops. This study evaluated the effects of salinity and water deficit on gas exchange, chlorophyll, and growth in sesame. The experiment was conducted at the Piro & aacute;s Experimental Farm, belonging to the Universidade da Integra & ccedil;& atilde;o Internacional da Lusofonia Afro-brasileira, Reden & ccedil;& atilde;o, Cear & aacute;, Brazil. The experimental design used was randomized blocks in a split-plot scheme, with four replicates. The plots correspond to five electrical conductivities of irrigation water (ECw-0.8, 1.6, 2.4, 3.2, and 4.0 dS m(-1)), and the subplots correspond to two water regimes, 50% and 100% of crop evapotranspiration (ETc). Increase in the electrical conductivity of irrigation water above 1.6 dS m(-1) reduces the CO2 assimilation rate, stomatal conductance, transpiration, and water use efficiency, resulting in lower vegetative development of BRS Anah & iacute; sesame. A 50% reduction in ETc reduced all physiological parameters, chlorophyll, and consequently growth in the sesame crop.
Conventional herbicide application methods can inefficient, and remotely piloted aircraft (RPA) provide a viable alternative. This study evaluated application quality and weed control efficacy using an RPA and an electric backpack sprayer. randomized block design with eight replications was used. Treatments consisted of two spray nozzle types (standard flat fan and air-induction flat fan) and two RPA flight heights (3.0 and 4.0 m), plus an untreated control and a standard treatment with a backpack sprayer. The spray mixture contained water, brilliant blue dye, glyphosate, and an adjuvant. RPA treatments achieved higher spray quality on the weed canopy and reduced soil losses compared with the backpack sprayer. Both methods resulted in effective weed control at 21 days after application, particularly the RPA treatments with flat fan nozzles at 3.0 and 4.0 m flight heights. RPA equipped with flat fan nozzles at a 3.0 m flight height achieved weed control efficacy equivalent to that of the electric backpack sprayer (98.5%), demonstrating that RPA technology represents a viable alternative for total-area weed management.
Soybean, the main oilseed crop cultivated in Brazil, faces challenges related to sustainability and dependence on chemical inputs. The use of beneficial microorganisms and cover crops may be an alternative to increase productivity and reduce costs. The objective of this study was to evaluate the effect of combining cover crops with multifunctional microorganisms on soybean development and to assess its financial viability. The experiment was conducted using a randomized block design in a 5 & times; 3 factorial scheme, with four replications. Treatments consisted of the combination of five cover crops [1) fallow; 2) Fagopyrum esculentum; 3) Pennisetum glaucum; 4) Mix 1 (Avena strigosa, A. sativa, Crotalaria ochroleuca, C. juncea, Raphanus sativus, and Eleusine coracana); and 5) Mix 2 (A. strigosa, C. spectabilis, Raphanus sativus, and F. esculentum)] with three microbiological management strategies (1. Embrapa: Serratia marcescens, Bacillus sp., Azospirillum brasilense, and Trichoderma koningiopsis; 2. Commercial: microbial consortium + Penergetic; and 3. Standard management). The evaluated variables were cover crop biomass production, 100-grain weight, yield, and economic analysis. Pearl millet showed the highest biomass production (8.52 t ha(-1)). The Commercial and Embrapa management strategies provided the highest average soybean yields (4.48 and 4.34 t ha(-1), respectively), both higher than the Standard management (4.26 t ha(-1)). Economic analysis indicated the highest financial return for the Commercial management ($799.49 ha(-1)). It is concluded that the adoption of plant growth-promoting microorganisms, combined with the use of cover crops, is a sustainable and economically viable practice for soybean cultivation.
Understanding effects of agricultural systems on ecological interactions between crops and weeds is essential for sustainable management. This study evaluated weed phytosociology and soybean productivity under conventional tillage (CT), no-tillage (NT), and integrated crop-livestock-forestry (CLF) systems in an Oxisol of the Brazilian Cerrado. A split-plot design was adopted, with three cropping systems assigned to main plots and three phytosociological survey periods to subplots, with eight replicates. Phytosociological assessments were conducted at 5 and 30 days after emergence (DAE) and at pre-harvest. Weed species were identified and quantified using the quadrat method. The following parameters were determined: density, relative density, frequency, relative frequency, abundance, relative abundance, relative importance index (Ri%), and similarity index. Soybean productivity was also assessed. Thirteen weed species were identified, belonging to seven botanical families. Poaceae predominated across systems and evaluation periods. Portulaca oleracea, Cenchrus echinatus, Digitaria insularis, and Digitaria horizontalis showed the highest mean Ri% values in all cropping systems and evaluation periods. Species distribution showed high variability in phytosociological parameters; however, similarities were observed among cropping systems and evaluation periods. NT and CLF systems resulted in significantly higher soybean productivity.
