ABSTRACT Abiotic stresses reduce the yield and quality of cotton production, however, this problem may be mitigated by exogenous elicitors. This study investigated physiological adjustments, ...improvement in productivity, and fiber yield and quality from naturally colored cotton BRS Topázio cultivar under leaf silicon spraying. Five doses of silicon (0, 50, 100, 150, and 200 mg L-1) were tested in a completely randomized design. The variables assessed were physiological, production, fiber yield and quality. Data were submitted to principal component analysis, multivariate and univariate variance, and multiple linear regression. Silicon promotes physiological adjustments, increased production, cotton fiber yield and quality. Optimum silicon dose varies depending on the variable response. Fiber quality from plants treated with silicon is within the expected pattern for this cultivar and the international standard D-4605 of the American Society for Testing and Materials. Therefore, planting BRS Topázio cultivar under silicon foliar applications may be recommended to improve the naturally colored fiber cotton production chain in the Brazilian semiarid region.
RESUMO Estresses abióticos reduzem o rendimento e a qualidade da produção de algodão e isso pode ser atenuado pelo uso de eliciadores exógenos. Este estudo investigou ajustes fisiológicos, melhoria da produtividade, rendimento e qualidade da fibra do algodão naturalmente colorido cultivar BRS Topázio sob pulverização de silício foliar. Foram testadas cinco doses de silício (0, 50, 100, 150, 200 mg L-1), em delineamento inteiramente casualizado; e avaliadas variáveis fisiológicas, produção, rendimento e qualidade de fibra. Os dados foram submetidos às análises de componentes principais, variância multivariada e univariada e regressão linear múltipla. O silício promove ajustes fisiológicos, aumento de produção, rendimento e qualidade de fibra de algodão. A dose ideal de silício varia em função da variável resposta avaliada. A qualidade da fibra de plantas tratadas com silício está dentro dos valores esperados para a cultivar e em conformidade com a norma internacional D-4605 da American Society for Testing and Materials. Portanto, o plantio da cultivar BRS Topázio com aplicações foliares de silício pode ser recomendado para melhoria da cadeia produtiva de algodão de fibra naturalmente colorida no semiárido do Brasil.
Introduction Salicylic acid has shown promise in alleviating water stress in cultivated plants. However, there is a lack of studies confirming its effectiveness in cowpea plants grown in field ...conditions. Therefore, this research aimed to evaluate the use of salicylic acid as a water stress mitigator in cowpea cultivars under different irrigation depths in field conditions. Methods Four cowpea cultivars (BRS Novaera, BRS Tapaihum, BRS Pujante, and BRS Pajeú) were subjected to different treatments: control (W100: 100% replacement of crop evapotranspiration – ETc), W50 (50% of ETc), W50+SA2 (50% of ETc + 276 mg L -1 of SA), and W50+SA4 (50% of ETc + 552 mg L -1 of SA). The treatments were combined in a 4×4 factorial scheme with three replications, arranged in a randomized block design. Results Water restriction had a negative impact on the water status, growth, gas exchange, and production of the cultivars while also leading to changes in the antioxidant metabolism and osmolyte concentration. The application of SA enhanced antioxidant activity and the synthesis of osmotic adjusters under stress conditions. The most effective concentration was 276 mg L -1 in stage R2 and 552 mg L -1 in stage V7, respectively. The BRS Pujante cultivar showed increased productivity under water restriction with SA application, while the BRS Tapaihum was the most tolerant among the cultivars studied. Discussion In summary, our findings underscore the importance of using SA to mitigate the effects of water restriction on cowpea cultivation. These discoveries are crucial for the sustainability of cowpea production in regions susceptible to drought, which can contribute to food security. We further add that the adoption of new agricultural practices can enhance the resilience and productivity of cowpea as an essential and sustainable food source for vulnerable populations in various parts of the world.
The carabid beetle Abaris basistriata (Coleoptera: Carabidae) is noteworthy for its predatory capabilities and its generalist function in the habitat. This study aimed to assess the influence of ...different temperatures on the development of A. basistriata and determine its thermal requirements. The insect was fed with larvae of Tenebrio molitor (Coleoptera: Tenebrionidae) and maintained at 18, 22, 25, and 28 ± 1 °C, 70 ± 10 % relative humidity, and 14-hour photoperiod. There were significant differences in the development time of stages and instars of A. basistriata as a function of temperature. Threshold temperatures for egg, larva, pupa, and preimaginal development were 10.68, 11.32, 12.67, and 11.73 °C, respectively. The thermal constants were 82.41, 264.83, 84.57, and 664.89 degree-days, respectively. The highest number of A. basistriata individuals reached the adult stage in the shortest time of development at 28 °C, where 70 % of survival was recorded. This finding suggests that 28 °C is the most favorable temperature for rearing this carabid species under laboratory conditions.
ABSTRACT Moringa oleifera is a species of great economic, social and environmental importance, being employed for multiple purposes. Thus, the objective of this study was to fit regression models for ...estimating leaflets area as non-destructive method from linear measurements of leaflets of M. oleifera seedlings. The study was carried out at the Center for Agrarian and Environmental Sciences of the Paraíba State University. Three hundred leaflets of M. oleifera were collected and measured to determine length “L” and width “W” and, subsequently, leaflets area was quantified through ImageJ® software. Using 200 leaflets, the univariate regression models were fitted, adopting length, width or the product of these dimensions “LW” and a bivariate model based on length and width as predictor variables of the observed leaflets area as dependent variable. The remaining 100 leaflets were used to evaluate the relationship between the observed leaflet area “OLA” and the estimated leaflets area “ELA”, based on Pearson’s correlation “r”; Willmott’s index of agreement “d” and index of confidence “c”; and root mean square error “RMSE”. It was found that allometric models can be used with high accuracy and performance to estimate the leaflets area of M. oleifera as non-destructive method, and recommended model is ELA = 0.035 + 0.720*LW. Future research is suggested for fittings of multivariate models to estimate the leaf area of M. oleifera from varying leaflet sizes, complete leaves, leaf fresh and dry weights, history of life and age of plants.
RESUMO A Moringa oleifera é uma espécie de grande importância econômica, social e ambiental, sendo empregada para múltiplos usos. Assim, objetivou-se ajustar modelos de regressão para estimativa de área de folíolos por método não-destrutivo a partir de medidas lineares de folíolos de mudas de M. oleifera. A pesquisa foi realizada no Centro de Ciências Agrárias e Ambientais da Universidade Estadual da Paraíba. Foram coletados 300 folíolos de M. oleifera, nos quais foram realizadas medidas para determinação do comprimento “L” e da largura “W” e, posteriormente, a área de folíolos foi quantificada por meio do software ImageJ®. Utilizando-se de 200 folíolos, os modelos de regressão univariados foram ajustados adotando-se comprimento, largura ou o produto destas dimensões “LW” e um modelo bivariado por meio do comprimento e largura como variáveis preditoras da área de folíolos observada como variável dependente. Com os 100 folíolos remanescentes, foi realizada a avaliação da relação entre a área de folíolos observada “OLA” e a estimada “ELA”, correlação de Pearson “r”; índice de concordância de Willmott “d” e de confiança “c”; e erro médio quadrático “RMSE”. Verificou-se que modelos alométricos podem ser usados com elevada precisão e performance para estimativa de área de folíolos de M. oleifera por método não-destrutivo, sendo recomendado o modelo ELA = 0,035 + 0,720*LW. Pesquisas futuras são sugeridas para ajustes de modelos multivariados para estimativa de área foliar de M. oleifera a partir de tamanhos de folíolos variados, folhas completas, massa fresca e seca das folhas, histórico de vida e idade das plantas.
Increasing population pressure generates a greater demand for food and consumer products, which forces the agricultural sector to optimize the production systems, as well as to use edible and ...energetic specie cultivars associated with abiotic stress-reducing substances. This investigation aimed to evaluate whether silicon (Si) promotes physiological adjustments, an increase in production, higher yield, and improved quality of naturally colored cotton fibers. Five doses of silicon (0, 50, 100, 150, and 200 mg L
−1
) were tested in a completely randomized design. The variables assessed were physiological, production, fibers yield and quality produced by BRS Safira cultivar. Data were submitted to principal component analysis, multivariate and univariate variance, and multiple linear regression. Silicon promotes physiological adjustments, increased production, and cotton fiber quality. Optimum Si dose varies depending on the variable response. Fiber quality from cotton plants treated with Si is within the expected pattern for this cultivar and the international standard D-4605 of the American Society for Testing and Materials for fiber quality measurement. Therefore, planting BRS Safira cultivar under Si foliar applications may be recommended to improve the naturally colored fiber cotton production chain in the Brazilian semiarid region.
Cassava wastewater has high organic load and concentration of nutrients and can cause damage to the environment when discarded indiscriminately. However, the residue can help agricultural production. ...Therefore, this study aimed to determine the appropriate doses of cassava wastewater to enable the highest production and quality of arugula. The experiment was conducted in a greenhouse, in a completely randomized design, consisting of eight treatments composed of the following doses: D1 = 0, D2 = 6.5, D3 = 13, D4 = 19.5, D5 = 26, D6 = 32.5, D7 = 39 and D8 = 45.5 m3 ha-1 of cassava wastewater with four replicates each. We used the arugula cultivar “Cultivada”, and samples of plant height, fresh matter, and shoot dry matter were performed at 15 and 30 days after emergence. The quality of arugula was evaluated through pH, total soluble solids and titratable total acidity. Cassava wastewater had a significant effect on plant height, fresh matter and dry matter of above ground part, pH and total soluble solids of arugula. However, titratable total acidity was not affected by treatments. Our results show that cassava wastewater is a good alternative fertilizer for arugula cultivation but at proper doses up to 26 m3 ha-1 applied through the crop cycle to avoid the deleterious effect of some nutrients in excess, such as potassium.
The association between population increase and the exploitation of natural resources and climate change influences the demand for food, especially in semi-arid regions, highlighting the need for ...technologies that could provide cultivated species with better adaptation to agroecosystems. Additionally, developing cultivation technologies that employ waste materials is highly desirable for sustainable development. From this perspective, this study aimed to evaluate whether seed priming with glass waste microparticles used as a silicon source under red light irradiation mitigates the effects of thermal and water stress on seedlings of Moringa oleifera. The experimental design was set up in randomized blocks using a 2 × 2 × 2 factorial arrangement consisting of seed priming (NSP—no seed priming, and SPSi—seed priming with glass microparticles under red light irradiation), soil water replenishment (W50—50%, and W100—100% of crop evapotranspiration—ETc), and temperature change (TC30°—30 °C day/25 °C night and TC40°—40 °C day/35 °C night). Seed priming with glass microparticles under red light irradiation mitigated the effects of thermal and water stress on seedlings of Moringa oleifera seedlings through the homeostasis of gas exchange, leaf water status, osmotic adjustment, and the antioxidant mechanism.
Moringa oleifera is one of the most important plants in the world due to its multiple uses as well tolerance to abiotic stress. However, it may presents low quality seedlings in protected environment ...under thermal and luminous stresses. The current study aimed to evaluate environmental microclimate changes; photomorphogenesis and water use of M. oleifera cuttings under light spectral and phytohormones variations, as well as to identify the most important variables to explain those effects. A completely randomized experimental design was used in a 4 x 4 factorial design with four replications. Four luminosity conditions, white (a transparent plastic layer), blue (two layers of blue cellophane paper), red (two layers of red cellophane paper), and extreme red lights (one layer of red cellophane and one of alternating blue cellophane) and four phytohormones concentrations (0, 25, 50, and 100%) were applied. M. oleifera semi-woody cuttings were collected from 7 am to 9 am from the M. oleifera mother plants, grown on a rural property located in the city of Lagoa Seca, Paraiba, Brazil, with the following characteristics: 15 cm in length, 4 to 5 mm in diameter, and 2 or 3 buds. Throughout the experimental period, environments were monitored to determine illuminance, average air temperature, relative humidity, soil average temperature, and evapotranspirated water consumption by cuttings. The numbers of shoots were recorded weekly. The number of surviving roots and shoots were measured 60 days after M. oleifera cuttings planting. Illuminance was reduced in environments under blue, red, and extreme red lights, respectively. The air temperature was reduced under blue light, while red and extreme red lights induced the increase on air temperature and relative humidity, soil temperature, and therefore, water consumption of cuttings. Protected environments when irradiated with blue light and application of phytohormones at concentrations of 25 and 50% enabled the shootings and survival of cuttings, although no root formation was observed after 60 days from planting. All variables were considered important to explain the effects.
ABSTRACT Reforestation is considered an effective method to improve soil quality and drain atmospheric CO2 by sequestering carbon, in both soil and vegetation. In this regard, the aim of this study ...was to evaluate the effects of converting areas cultivated with sugarcane to eucalypt plantations (Eucalyptus spp.) on soil quality and carbon sequestration in a Latossolo (Ferralsol) in the Atlantic Forest region of the Alagoas state, Brazil, through multivariate analysis. The systems under evaluation consisted of four areas: one area cultivated with sugarcane for approximately 20 years, taken as the reference area of this study, and the other three adjacent areas cultivated with eucalypt at 1 (E1), 3 (E3) and 6 (E6) years of age, previously cultivated with sugarcane. Physical (bulk density - BD, Mean weight-diameter - MWD, geometric mean diameter - GMD and aggregate stability index - ASI), chemical (soil organic carbon - SOC, total nitrogen - TN, labile carbon - LC and recalcitrant carbon - RC) and biological (Microbial biomass carbon - MBC, soil carbon respiration - C-CO2 and metabolic quotient - qCO2) properties of soil were evaluated. Data were collected, standardized and submitted to exploratory analysis with principal components. The results show that SOC, LC, TN, GMD, MWD and ASI increased, while BD showed a reduction in E3 and E6 systems. The conversion of sugarcane cultivation with burning of straw and manual harvest into eucalypt plantations was efficient at promoting SOC sequestration and improving physical, chemical and biological properties of soil.
RESUMO O reflorestamento é considerado um método eficaz para melhorar a qualidade do solo e drenar o CO2 atmosférico por meio do sequestro de carbono, tanto na vegetação quanto no solo. Nesse sentido, o objetivo deste estudo foi avaliar os efeitos da conversão do cultivo de cana-de-açúcar em plantações de eucalipto (Eucalyptus spp.) sobre a qualidade do solo e sequestro de carbono em um Latossolo na região da Mata Atlântica do estado de Alagoas, Brasil, por meio de análise multivariada. Os sistemas avaliados consistiram em quatro áreas, sendo uma cultivada com cana-de-açúcar, por aproximadamente 20 anos, tomada como área de referência do estudo; e três áreas adjacentes, cultivadas com floresta de eucalipto por 1 (E1), 3 (E3) e 6 (E6) anos, anteriormente eram cultivadas com cana-de-açúcar. Foram avaliadas as propriedades físicas (densidade do solo - DS, diâmetro médio ponderado - DMP, diâmetro médio geométrico - DMG e índice de estabilidade de agregados - IEA), químicas (carbono orgânico do solo - COS, nitrogênio total - NT, carbono lábil - CL e carbono recalcitrante - CR) e biológicas (carbono da biomassa microbiana - CBM, carbono respirado do solo - C-CO2 e quociente metabólico - qCO2) do solo. Os dados foram padronizados e submetidos à Análise de Componentes Principais. Os resultados mostram que COS, CL, NT, DMG, DMP e IEA aumentaram, enquanto DS apresentou redução nos sistemas E3 e E6. A conversão do cultivo de cana-de-açúcar com queima da palhada e colheita manual para plantações de eucaliptos foi eficiente em promover o sequestro de COS e melhorar as propriedades físicas, químicas e biológicas do solo.
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