Use of Proline to Induce Salt Stress Tolerance in Guava.

Guava is a fruit tree with high potential in the semi-arid region of northeast Brazil. However, qualitative and quantitative water scarcity is a limiting factor for the expansion of irrigated agriculture. Thus, it is necessary to use techniques to mitigate the effects of salt stress, such as foliar application of proline. The objective of this study was to evaluate the effect of foliar application of proline as a mitigator of salt stress effects on the morphophysiology of guava cv. Paluma. The experiment was carried out under field conditions at the 'Rolando Enrique Rivas Castellón' Experimental Farm in São Domingos, PB, Brazil, using a randomized block design in a 5 × 4 factorial scheme referring to five levels of electrical conductivity of irrigation water, ECw (0.8, 1.5, 2.2, 2.9, and 3.5 dS m-1) and four concentrations of proline (0, 8, 16, and 24 mM). Salinity above 0.8 dS m-1 compromised gas exchange, photosynthetic pigment synthesis, photochemical efficiency, and growth of guava plants at 360 days after transplanting. Foliar application of proline at a concentration of 24 mM mitigated the effect of salt stress on the relative water content, stomatal conductance, and carotenoid contents in plants irrigated with 3.6 dS m-1 water. Meanwhile, a proline concentration of up to 18 mM resulted in higher transpiration, CO2 assimilation rate, instantaneous carboxylation efficiency, and absolute growth rate in stem diameter under ECw of 0.8 dS m-1. Proline concentration of up to 24 mM increased the biosynthesis of photosynthetic pigments and the relative growth rate in stem diameter of guava in the period from 190 to 360 days after transplanting.

Hydrogen Peroxide Alleviates Salt Stress Effects on Gas Exchange, Growth, and Production of Naturally Colored Cotton.

Cotton is one of the most exploited crops in the world, being one of the most important for the Brazilian Northeast. In this region, the use of irrigation is often necessary to meet the water demand of the crop. Water is often used from underground wells that have a large amount of salt in their constitution, which can compromise the development of crops, so it is vital to adopt strategies that reduce salt stress effects on plants, such as the foliar application of hydrogen peroxide. Thus, the objective of this study was to evaluate the effects of foliar application of hydrogen peroxide on the gas exchange, growth, and production of naturally colored cotton under salt stress in the semi-arid region of Paraíba, Brazil. The experiment was carried out in a randomized block design in a 5 × 5 factorial scheme, with five salinity levels of irrigation water-ECw (0.3, 2.0, 3.7, 5.4 and 7.1 dS m-1)-and five concentrations of hydrogen peroxide-H2O2 (0, 25, 50, 75 and 100 µM), and with three replicates. The naturally colored cotton 'BRS Jade' had its gas exchange, growth, biomass production, and production reduced due to the effects of salt stress, but the plants were able to produce up to the ECw of 3.97 dS m-1. Foliar application of hydrogen peroxide at the estimated concentrations of 56.25 and 37.5 µM reduced the effects of salt stress on the stomatal conductance and CO2 assimilation rate of cotton plants under the estimated ECw levels of 0.73 and 1.58 dS m-1, respectively. In turn, the concentration of 12.5 µM increased water-use efficiency in plants subjected to salinity of 2.43 dS m-1. Absolute and relative growth rates in leaf area increased with foliar application of 100 µM of hydrogen peroxide under ECw of 0.73 and 0.3 dS m-1, respectively. Under conditions of low water salinity (0.3 dS m-1), foliar application of hydrogen peroxide stimulated the biomass formation and production components of cotton.

Hydrogen peroxide in the induction of tolerance of guava seedlings to salt stress / Peróxido de hidrogênio na indução de tolerância de mudas de goiabeira ao estresse salino

Guava cultivation plays a significant role in the socioeconomic development of the Brazilian semi-arid region, contributing to employment opportunities and income generation. However, this region often faces the challenge of high levels of dissolved salts in water sources, necessitating strategies to mitigate the adverse effects of salt stress on plants. This study aimed to assess the impact of foliar application of hydrogen peroxide on gas exchange, photochemical efficiency, growth, and quality of guava seedlings subjected to salt stress. The experiment was conducted under greenhouse conditions in Pombal - PB, Brazil, following a randomized block design. The treatments comprised a 5 × 4 factorial arrangement, representing five levels of electrical conductivity in the irrigation water (ECw: 0.3, 1.3, 2.3, 3.3, and 4.3 dS m-1) and four concentrations of hydrogen peroxide (H2O2: 0, 25, 50, and 75 µM). Each treatment was replicated four times, with two plants per plot. Irrigation with water having an electrical conductivity of 0.3 dS m-1 significantly inhibited gas exchange, photochemical efficiency, and growth of guava seedlings after 91 days of emergence. Foliar application of hydrogen peroxide at concentrations up to 75 µM did not alleviate the effects of salt stress during the seedling formation phase of guava plants. Guava cv. Paluma was found to be sensitive to water salinity during the seedling formation phase, with a threshold level of 0.3 dS m-1 and a decrease in the growth rate of 11.48% per unit increase in salinity.(AU)

A goiabeira é uma cultura importante no cenário socioeconômico da região semiárida brasileira, sendo uma fonte de geração de emprego e renda. Contudo, nesta região é comum a ocorrência de fontes hídricas com altos teores de sais dissolvidos e assim são necessárias estratégias que visem minimizar os efeitos deletérios do estresse salino nas plantas. Neste contexto, objetivou-se com este trabalho avaliar os efeitos da aplicação foliar com peróxido de hidrogênio nas trocas gasosas, eficiência fotoquímica, crescimento e qualidade de mudas de goiabeira sob estresse salino. O experimento foi conduzido sob condições de casa de vegetação em Pombal, Paraíba, utilizando-se o delineamento de blocos casualizados, com tratamentos arranjados em esquema fatorial 5 × 4, referentes a cinco níveis de condutividade elétrica da água - CEa (0,3; 1,3; 2,3; 3,3 e 4,3 dS m-1) e quatro concentrações de peróxido de hidrogênio ­ H2O2 (0, 25, 50 e 75 µM) com quatro repetições e duas plantas por parcela. A irrigação com água de condutividade elétrica a partir de 0,3 dS m-1 inibiu as trocas gasosas, eficiência fotoquímica e crescimento de mudas de goiabeira, aos 91 dias após a emergência. A aplicação foliar de peróxido de hidrogênio em concentrações de até 75 µM não amenizou os efeitos do estresse salino em plantas de goiabeira na fase de formação de mudas. A goiabeira cv. Paluma é classificada como sensível a salinidade da água na fase de formação de mudas, sendo o nível limiar de 0,3 dS m-1 e diminuição por aumento unitário de 11,48%.(AU)

ECOPHYSIOLOGY AND GROWTH OF BASIL (Ocimum basilicum) UNDER SALINE STRESS AND SALICYLIC ACID / Ecofisiología y crecimiento de albahaca (Ocimum basilicum) bajo estrés salino y ácido salicílico

ABSTRACT Salinity is one of the major problems of modern agriculture, affecting physiological, growth and plant production. Basil (Ocimum basilicum) is a plant widely used in cooking, and in the pharmaceutical and cosmetics industries. Salicylic acid can be a strategy to mitigate the harmful effects of saline stress on basil plant. The present study aimed to evaluate plants with, gas exchange, chlorophyll a fluorescence and chlorophyll indices of basil (cv. Cinnamon) plants under saline stress and salicylic acid. The experimental design was a randomized block design in a 5x5 incomplete factorial scheme generated through the central composite design. The factors we five electrical conductivities of irrigation water (ECw- 0.5, 1.3, 3.25, 5.2 and 6.0 dS m-1) and five doses of salicylic acid (SA- 0.0, 0.29, 1.0, 1.71 and 2.0 mM), with five replications and two plants per replicate. Growth, gas exchange, chlorophyll a fluorescence and chlorophyll indices of O. basilicum cv. Cinnamon were evaluated. Canonical variables analysis and confidence ellipses (p ≤ 0.01) were performed to study the interrelationship between variables and factors. Salicylic acid alleviated the deleterious effects of salt stress on growth, gas exchange, chlorophyll fluorescence and chlorophyll indices of basil.

RESUMEN La salinidad es uno de los mayores problemas de la agricultura moderna, afectando la fisiología, el crecimiento y la producción vegetal. La albahaca (Ocimum basilicum) es una planta muy utilizada en la cocina y en las industrias farmacéutica y cosmética. El ácido salicílico puede ser una estrategia para mitigar los efectos nocivos del estrés salino en las plantas de albahaca. El objetivo del presente estudio fue evaluar el crecimiento, intercambio de gases, fluorescencia de clorofila a e índices de clorofila de plantas de albahaca (cv. Cinnamon) bajo estrés salino y ácido salicílico. El diseño experimental fue un diseño de bloques al azar en un esquema factorial incompleto de 5x5 generado a través del diseño compuesto central. Los factores fueron cinco conductividades eléctricas del agua de riego (ECw- 0,5, 1,3, 3,25, 5.2 y 6,0 dS m-1) y cinco dosis de ácido salicílico (SA- 0,0, 0,29, 1,0, 1.71 y 2,0 mM), con cinco repeticiones y dos plantas por réplica. Crecimiento, intercambio de gases, fluorescencia de clorofila a e índices de clorofila de O. basilicum cv. Cinnamon fue evaluado. Se realizaron análisis de variables canónicas y elipses de confianza (p≤ 0.01) para estudiar la interrelación entre variables y factores. El ácido salicílico alivió los efectos nocivos del estrés salino sobre el crecimiento, el intercambio de gases, la fluorescencia de la clorofila y los índices de clorofila de la albahaca.

Morphophysiology and production components of mini-watermelon under water replenishment and nitrogen fertilization levels / Morfofisiologia e componentes de produção de mini-melancia sob níveis de reposição hídrica e adubação nitrogenada

In the semi-arid region of Northeast Brazil, the combination of irregular rainfall and high evapotranspiration creates a consistent water deficit in plants for most months of the year. This factor prominently limits the vegetable production potential. Consequently, finding effective strategies to alleviate the adverse impacts of water deficit on plants becomes imperative to ensure successful cultivation under irrigated conditions. Within this framework, the objective of this study was to evaluate the influence of nitrogen fertilization on both the morphophysiology and production components of 'Sugar Baby' mini-watermelon plants. The experiment was carried out at the 'Rolando Rivas Castellón' experimental farm in São Domingos, PB, Brazil, within controlled greenhouse conditions. A randomized block design was employed using a 4 × 4 factorial arrangement consisting of four distinct water replenishment levels (50, 75, 100 [control], and 125% of the crop's actual evapotranspiration [ETr]) and four nitrogen application rates (50, 75, 100, and 125% of the recommended rate). Each treatment combination was replicated three times, leading to a total of 48 plants being studied. Gas exchange parameters, content of photosynthetic pigments, relative water content, and electrolyte leakage were assessed. Furthermore, growth metrics, biomass production, production components, and the postharvest quality of 'Sugar Baby' mini-watermelon fruits were also evaluated. Subjecting the plants to deficit irrigation with 50% ETr reduced gas exchange, synthesis of photosynthetic pigments, growth, and fruit quality of 'Sugar Baby' mini-watermelon, irrespective of the nitrogen rate. On the other hand, the irrigation amount of 125% ETr coupled with nitrogen fertilization at 100% of the recommended rate provided higher values of total chlorophyll content, number of leaves, dry mass of root, stem, shoot, and total plant, and the pH value of 'Sugar Baby' mini-watermelon.(AU)

No semiárido do Nordeste do Brasil, a irregularidade de chuvas e elevada evapotranspiração proporcionam déficit hídrico nas plantas na maior parte dos meses do ano, destacando-se como fator limitante para produção de olerícolas. Assim, a identificação de estratégias capazes de amenizar os efeitos do déficit hídrico nas plantas é essencial para produção sob condições irrigadas. Nesse contexto, objetivou-se avaliar o efeito da adubação nitrogenada na morfofisiologia e nos componentes de produção de mini-melancia 'Sugar Baby'. O experimento foi conduzido na Fazenda Experimental 'Rolando Rivas Castellón', São Domingos, Paraíba, sob condições de casa de vegetação, utilizando-se o delineamento de blocos casualizados em esquema fatorial 4 × 4, correspondendo a quatro níveis de reposição hídrica (50, 75, 100 - controle e 125% da evapotranspiração real da cultura - ETr) e quatro doses de nitrogênio - DN (50, 75, 100 e 125% da dose recomendada), com 3 repetições, totalizando 48 plantas. Foram avaliadas as variáveis de trocas gasosas, os teores de pigmentos fotossintéticos, o conteúdo relativo de água e o extravasamento de eletrólitos, o crescimento e a produção de fitomassa, os componentes de produção e a qualidade pós-colheita dos frutos de mini-melancia. A irrigação deficitária com 50% da evapotranspiração real inibiu as trocas gasosas, a síntese de pigmentos fotossintéticos, o crescimento, e a qualidade dos frutos da mini-melancieira 'Sugar Baby', independente da dose de nitrogênio. A lâmina de água com 125% da evapotranspiração real combinada à adubação de 100% da recomendação de nitrogênio proporcionou maiores teores de clorofilas totais, número de folhas e de fitomassa seca das raízes, caule, total, parte aérea e pH dos frutos de mini-melancieira 'Sugar Baby'.(AU)

Ecophysiology of Mesosphaerum suaveolens (L) Kuntze (Lamiaceae) under saline stress and salicylic acid / Ecofisiologia de Mesosphaerum suaveolens (L) Kuntze (Lamiaceae) sob estresse salino e ácido salicílico

Mesosphaerum suaveolens (L.) Kuntze is a species widely used in folk medicine and has a high aromatic and therapeutic potential. However, its cultivation in semi-arid regions can be limited by salts in the irrigation water. The objective of this study was to evaluate the effect of salicylic acid (SA) as a mitigator of saline stress on the growth and gas exchange of M. suaveolens. The experimental design used was the randomized blocks in an incomplete factorial scheme (Central Composite Design), with five electrical conductivities water (ECw = 0.5, 1.45, 5.0, 8.55, and 10.0 dS m-¹) and five SA doses (0.0, 0.29, 1.0, 1.71, and 2.0 mM). Plant height, number of leaves, stem diameter, leaf area, root length, and height/diameter ratio, and gas exchange (stomatal conductance, net CO2 assimilation rate, transpiration rate, instantaneous, and intrinsic water use efficiency, instantaneous carboxylation efficiency, and leaf temperature) were evaluated. The application of 0.9 mM SA attenuates the negative effect of saline stress on the number of leaves and leaf area of M. suaveolens. The application of SA stimulates the number of leaves, plant height, and root growth, but does not affect the gas exchange of M. suaveolens. ECw reduces the growth and gas exchange of M. suaveolens plants.

Mesosphaerum suaveolens (L.) Kuntze é uma espécie muito utilizada na medicina popular e que possui um elevado potencial aromático e terapêutico. No entanto, sua exploração em regiões semiáridas pode ser limitada em função do teor de sais na água de irrigação. O objetivo deste estudo foi avaliar o efeito do ácido salicílico (AS) como mitigador do estresse salino sobre o crescimento e trocas gasosas de M. suaveolens. O delineamento estatístico utilizado foi o de blocos casualizados, em esquema fatorial incompleto (Delineamento Composto Central), com cinco condutividades elétricas de água (CEa = 0,5, 1,45, 5,0, 8,55 e 10,0 dS m-¹) e cinco doses de AS (0,0, 0,29, 1,0, 1,71 e 2,0 mM). Foram avaliados a altura de plantas, número de folhas, diâmetro do caule, área foliar, comprimento de raiz e relação altura/diâmetro do caule e trocas gasosas (condutância estomática, taxa de assimilação líquida de CO2, transpiração, eficiência instantânea e eficiência intrínseca no uso da água e de carboxilação e a temperatura foliar). A aplicação do AS na dose de 0,9 mM atenua o efeito do estresse salino sobre o número de folhas e área foliar. A aplicação de AS estimula o número de folhas e o crescimento em altura e da raiz, mas não afeta as trocas gasosas. A CEa reduz o crescimento e as trocas gasosas das plantas de M. suaveolens.

Impact of biostimulant and saline water on cape gooseberry (Physalis peruviana L.) in Brazil.

Production of Physalis peruviana L. has gained prominence in Northeastern Brazil. However, salinity limits the crop development in the Brazilian semiarid. Thus, this research aimed to evaluate the application of Acadian® biostimulant as mitigant of the deleterious effects of salinity on growth and gas exchange of P. peruviana plants. The experiment was combining different electrical conductivity of irrigation water (0.50, 1.23, 3.00, 4.44, and 5.50 dS m-1) and biostimulant doses (0.00, 1.45, 5.00, 8.55, and 10.00 mL L-1). The main variables evaluated were plant height, stem diameter, number of leaves, root length, leaf area, specific leaf area, leaf area ratio, absolute and relative growth rate for plant height, and gas exchange. Experimental results showed that an increase in electrical conductivity of irrigation water had negatively affected the growth components and gas exchange in P. peruviana. Also, the application of seaweed-based biostimulant improves the photosynthetic capacity (43.3%), reduces transpiration rate (26.5%) and water loss by this process, further it attenuated the deleterious effects of salinity on specific leaf area, leaf area ratio, and stomatal conductance. To further elucidate the effectiveness of biostimulant application as a mitigant of salt stress, research aimed at the biochemical and enzyme activities of the plant's antioxidant system should be conducted to better understand this process.

Photosynthesis of Physalis peruviana under different densities of photons and saline stress

Physalis peruviana L. is a solanacea that has been gaining prominence due to its fruits presenting good acceptance in the national and international market. However, several abiotic factors, such as salinity, can cause physiological disturbances in plants, and these changes may be of greater or lesser intent according to species. Therefore, the objective of the present work was to evaluate the physiological behavior of P. peruviana submitted to different fluxes of photosynthetically active photons (PPFD) and saline stress. The experimental design was a randomized block design with three saline levels (ECw) (0.5, 2.75 and 5.00 dS m-1) with four replications. Gas exchange measurements were performed with a portable infrared gas analyzer. Liquid CO2 assimilation, stomatal conductance, internal CO2 concentration, water use efficiency and instantaneous carboxylation efficiency were measured. Data were subjected to analysis of variance by F test and in cases of significance applied to regression analysis. The increase in PPFD provided reductions in stomatal conductance up to the density of approximately 400 µmol m-2s-1, being more pronounced in ECw of 2.75 and 5.0 dS m-1. The maximum CO2 assimilation rates in the three salinities are different according to the PPFD. The salinity of irrigation water reduced the quantum efficiency of photosynthesis in P. peruviana plants.

Seed Quality and Vigor of Germination of Moringa oleífera Lam. in Saline Stress

Abstract Moringa oleifera Lam., is a tree species that has several purposes of use, standing out in the recovery of degraded areas and the use of seeds as biodsorbents in water clarification. However, ony a little is known about the behavior of seed germination under saline conditions, common in soils and water in the Brazilian Northeast. Thus, the objective was to evaluate the increment of water during the soaking and seed germination of M. oleífera that were submitted to different electrical conductivity of the irrigation water. The work was developed following a completely randomized design, with stress simulation employing saline solutions at the concentrations of 0.0; 3.0; 6.0 and 9.0 dS m-1. To determine the soaking curve, the water increment of the soaked seeds in the different saline solutions was monitored at regular intervals with four replications per treatment. To characterize the physiological quality of the seeds, the percentage, first count, speed index, average time and average germination speed were evaluated. The M. oleífera is tolerant to the effect of salinity during the germination phase, however seed vigor is reduced as a function of increased salinity. Soaking the seeds makes begin the phase II of the germination process around 10 hours and extends for up to 50 hours, when phase III begins, they absorb approximately 0.2 g of water and require 86 hours for germination. Salinity reduces the absorption and increase of water in the seeds.

Physiological changes in Solanum lycopersicum L. in the presence of root-knot nematodes and salicylic acid / Alterações fisiológicas em Solanum lycopersicum L. na presença de nematóides das galhas e ácido salicílico

Nematodes of the genus Meloidogyne spp. are one of the tomato culture's main pathogens. According to their soil infestation level, physiological changes may occur. Consequently, it is extremely important to employ given products to minimize their effect. A feasible option is the salicylic acid, a phytohormone that can induce into resistance due to its ability to increase the production level of some pathogenicity proteins. Therefore, the purpose hereof was to assess the effect of salicylic acid on the physiology of tomato plants subject to different populational densities of Meloidogyne javanica. The design employed was one of randomized blocks, in an incomplete factorial scheme, using the Box Central Compound (BCC) matrix with five nematode populational densities (PD) (0; 5815; 20000; 34184; and 40000 eggs per plant) and five salicylic acid doses (0.0; 0.29; 1.0; 1.71; and 2.0 mM), with four repetitions and two plants per experimental patch. The gas exchanges, fluorescence, and chlorophyll levels were evaluated 45 days after the transplant and soil infestation. The data were submitted for analysis of variance through the F test and, in the significance cases, the polynomial regression analysis was performed. For stomatal conductance, a greater reduction was seen at the PD of 21755 eggs per plant, a fact that might have decreased the liquid assimilation of CO2 and the efficiency of carboxylation. The salicylic acid (SA) affected the CO2 liquid assimilation and the efficiency of carboxylation. The infestation of M. javanica in tomato plants negatively affected the gas exchange and the chlorophyll levels because the SA application did not mitigate the negative effect thereof.

Os nematoides do gênero Meloidogyne spp. são um dos principais patógenos na cultura do tomate, podendo causar alterações fisiológicas em função do nível de infestação do solo. O uso de produtos que minimize seus efeitos é de suma importância, nesse sentido, o ácido salicílico pode ser uma alternativa viável, visto que, esse fitormônio pode induzir a resistência devido à capacidade de proporcionar um aumento na produção de algumas proteínas de patogenicidade. Com isso, objetivou-se avaliar o efeito do ácido salicílico na fisiologia do tomateiro submetido a diferentes densidades populacionais de Meloidogyne javanica. O delineamento utilizado foi o de blocos casualizados, em esquema fatorial incompleto, utilizando-se a matriz Composto Central de Box (CCB) com cinco densidades populacionais (DP) de nematoides (0; 5815; 20000; 34184 e 40000 ovos por planta) e cinco doses de ácido salicílico (0,0; 0,29; 1,0; 1,71 e 2,0 mM), com quatro repetições e duas plantas por parcela experimental. Foram avaliadas as trocas gasosas, fluorescências e índices de clorofilas aos 45 dias após o transplantio e infestação do solo. Os dados foram submetidos à análise de variância pelo teste F e nos casos de significância foi realizada análise de regressão polinomial. Para a condutância estomática, observou-se uma maior redução na DP de 21755 ovos por planta, fato que pode ter ocasionado reduções na assimilação líquida de CO2 e na eficiência de carboxilação. O ácido salicílico (AS) influenciou na assimilação líquida de CO2 e eficiência de carboxilação. A infestação por M. javanica em plantas de tomateiro influenciou negativamente nas trocas gasosas e nos teores de clorofila, sendo que a aplicação do AS não atenuou os efeitos negativos desses patógenos.

Aplicação foliar de prolina no crescimento e fisiologia do milho verde cultivado em solo salinizado / Proline of leaf application on growth and physiology of green corn on soil salinity different levels

O milho (Zea mays L.) é uma das culturas mais cultivadas no mundo. No Brasil, este cereal tem ampla diversidade de uso. A maioria das áreas onde há produção de milho, utiliza-se a irrigação, entretanto, quando realizada de forma inadequada, torna-se preponderante para a salinização dos solos. Assim, objetivou-se avaliar, o efeito da aplicação foliar de prolina no crescimento e fisiologia da cultura do milho cultivado em solo salinizado. O experimento foi conduzido no Centro de Ciência e Tecnologia Agroalimentar (CCTA), pertencente à Universidade Federal de Campina Grande (UFCG), Pombal, PB, no período de março a abril de 2015, utilizando-se a variedade de milho AG 1051. Os tratamentos foram constituídos por dois níveis de salinidade do solo, (CE= 3,26 e 0,86 dS/m) e cinco concentrações de prolina (0; 2,5; 5,0; 7,5 e 10 mmol L-¹) aplicada via foliar nas plantas de milho. O delineamento experimental foi inteiramente casualizado, no esquema fatorial 2 x 5, com quatro repetições. Foi observado um maior crescimento e acúmulo de massa quando as plantas foram conduzidas em solo de menor salinidade (CE= 0,86 dS/m).  A transpiração foi influenciada pela salinidade e pela concentração de prolina. A maior taxa de concentração intercelular de CO2 (Ci) foi obtida na concentração de 7,5 mmol L-¹ prolina. As concentrações de prolina não influenciaram nos aspectos de...(AU)

Corn (Zea mays L.) is one of the most cultivated crops in the world. In Brazil, this cereal has a wide diversity of use. Most of the areas where maize production is used is irrigation, however, when performed inadequately it becomes preponderant for salinization of soils. The effect of proline foliar application on the growth and physiology of the green maize cultivated in salinized soil was evaluated. The experiment was conducted at the Center for Agro-Food Science and Technology (CCTA), belonging to the Federal University of Campina Grande (UFCG), Pombal, PB, from March  to April 2015, using maize variety AG 1051. The treatments consisted of two levels of soil salinity (EC = 3.26 and 0.86 dS/m) and five concentrations of proline (0, 2.5, 5.0, 7.5 and 10 mmol L -¹) applied by leaf on corn plants. The experimental design was completely randomized, in the 2 x 5 factorial scheme, with four replications. A higher growth and mass accumulation was observed when the plants were conducted in soil of lower salinity (CE = 0.86 dS/m). Transpiration was influenced by salinity and proline concentration. The highest rate of intercellular CO2 concentration (Ci) was obtained at the concentration of 7.5 mmol L-¹ proline. Proline concentrations did not influence the growth and mass accumulation aspects of maize.(AU)

Aplicação foliar de prolina no crescimento e fisiologia do milho verde cultivado em solo salinizado / Proline of leaf application on growth and physiology of green corn on soil salinity different levels

O milho (Zea mays L.) é uma das culturas mais cultivadas no mundo. No Brasil, este cereal tem ampla diversidade de uso. A maioria das áreas onde há produção de milho, utiliza-se a irrigação, entretanto, quando realizada de forma inadequada, torna-se preponderante para a salinização dos solos. Assim, objetivou-se avaliar, o efeito da aplicação foliar de prolina no crescimento e fisiologia da cultura do milho cultivado em solo salinizado. O experimento foi conduzido no Centro de Ciência e Tecnologia Agroalimentar (CCTA), pertencente à Universidade Federal de Campina Grande (UFCG), Pombal, PB, no período de março a abril de 2015, utilizando-se a variedade de milho AG 1051. Os tratamentos foram constituídos por dois níveis de salinidade do solo, (CE= 3,26 e 0,86 dS/m) e cinco concentrações de prolina (0; 2,5; 5,0; 7,5 e 10 mmol L-¹) aplicada via foliar nas plantas de milho. O delineamento experimental foi inteiramente casualizado, no esquema fatorial 2 x 5, com quatro repetições. Foi observado um maior crescimento e acúmulo de massa quando as plantas foram conduzidas em solo de menor salinidade (CE= 0,86 dS/m).  A transpiração foi influenciada pela salinidade e pela concentração de prolina. A maior taxa de concentração intercelular de CO2 (Ci) foi obtida na concentração de 7,5 mmol L-¹ prolina. As concentrações de prolina não influenciaram nos aspectos de...

Corn (Zea mays L.) is one of the most cultivated crops in the world. In Brazil, this cereal has a wide diversity of use. Most of the areas where maize production is used is irrigation, however, when performed inadequately it becomes preponderant for salinization of soils. The effect of proline foliar application on the growth and physiology of the green maize cultivated in salinized soil was evaluated. The experiment was conducted at the Center for Agro-Food Science and Technology (CCTA), belonging to the Federal University of Campina Grande (UFCG), Pombal, PB, from March  to April 2015, using maize variety AG 1051. The treatments consisted of two levels of soil salinity (EC = 3.26 and 0.86 dS/m) and five concentrations of proline (0, 2.5, 5.0, 7.5 and 10 mmol L -¹) applied by leaf on corn plants. The experimental design was completely randomized, in the 2 x 5 factorial scheme, with four replications. A higher growth and mass accumulation was observed when the plants were conducted in soil of lower salinity (CE = 0.86 dS/m). Transpiration was influenced by salinity and proline concentration. The highest rate of intercellular CO2 concentration (Ci) was obtained at the concentration of 7.5 mmol L-¹ proline. Proline concentrations did not influence the growth and mass accumulation aspects of maize.

Morphophysiology of yellow passion fruit seedlings under application of nitrogen and potassium and irrigation with highsalinity water / Morfofisiologia de mudas de maracujazeiro amarelo sob aplicaçãode nitrogênio e potássio e irrigadas com águas salinas

Salinity is one of the most problematic abiotic stresses in agriculture globally, especially in semi-arid regions. Thus, the application of nutrients, such as nitrogen and potassium to improve plant nutritional conditions may be a viable alternative to minimize the negative effects of saline stress. Therefore, the aim of this study was to evaluate the morphophysiological behavior of yellow passion fruit seedlings under varying nitrogen and potassium doses and irrigation with salt water. The experimental design was a randomized complete block with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Design with five electrical conductivities of irrigation water (0.5, 0.98, 2.15, 3.32, and 3. 80dS m-¹) and five increasing doses of nitrogen and potassium (0.0, 29.08, 100.0, 170.92, and 200.0%). Leaf, stem, and root dry phytomass and gas exchange were evaluated 75 days after sowing. The increase in salinity had negative effects on the morphological and physiological characteristics of yellow passion fruit seedlings. The application of nitrogen and potassium positively influenced photosynthetic rate and leaf and root dry phytomasses. The application of nitrogen and potassium increased intercellular CO2 concentration and transpiration in yellow passion fruit seedlings under saline stress.(AU)

A salinidade é um dos estresses abióticos mais preocupantes na agricultura mundial, principalmente nas regiões semiáridas. Assim, a aplicação de nutrientes como nitrogênio e o potássio visando melhorar as condições nutricionais das plantas pode ser uma alternativa viável para minimizar os efeitos negativos do estresse salino. Portanto, objetivou-se avaliar o comportamento morfofisiológico de mudasd e maracujazeiro-amarelo sob doses de nitrogênio e potássio e irrigadas com águas salinas. O delineamento utilizado foi em blocos casualizados, em esquema fatorial incompleto 5x5, gerados a partir da matriz Composto Central de Box com cinco condutividades elétricas da água de irrigação (0,5; 0,98; 2,15; 3,32 e 3,80 dS m-¹) e cinco doses crescentes de nitrogênio e potássio (0,0; 29,08; 100,0; 170,92 e 200,0%). Foram avaliadas as fitomassas seca de folha, caule e raiz e as trocas gasosas aos 75 dias após a semeadura. O aumento da salinidade proporciona efeitos negativos nas características morfofisiológicas do maracujazeiro amarelo. A aplicação de nitrogênio e potássio influencia positivamente na taxa fotossintética e fitomassa seca das folhas e raiz. A aplicação de nitrogênio e potássio aumenta concentração intercelular de CO2 e transpiração de mudas de maracujazeiro-amarelo sob estresse salino.(AU)

Effects of irrigation water salinity and salicylic acid on germination and vigor of Mesosphaerum suaveolens (L. ) Kuntze / Efeitos da salinidade da água de irrigação e do ácido salicílico na germinação e no vigor de Mesosphaerum suaveolens (L. ) Kuntze

Salinity is one of the factors that negatively impact plant growth and productivity; therefore, it is necessary to seek solutions that help mitigate the degenerative action of saline stress on crops. The objective of this study was to evaluate the effects of salicylic acid (SA) on the germination and vigor of Mesosphaerum suaveolens (L.) Kuntze seeds subjected to salinity. The experiment was carried out using a completely randomized design, in an incomplete 5 × 5 factorial scheme, with five levels of electrical conductivity of irrigation water (ECw - 0.0, 1.45, 5.00, 8.55, and 10.00 dS m-1) and five doses of SA (0.0, 0.29, 1.00, 1.71, and 2.00 mM), with four replications of 50 seeds, totaling nine combinations generated via a central composite design. The germination percentage, first germination count, germination speed index, average germination time, percentage of abnormal seedlings, shoot, root, and seedling lengths, and total seedling dry mass were evaluated. Salicylic acid attenuated the effect of saline stress on initial growth, mitigating damage to root and shoot lengths. Seed priming with salicylic acid improved germination and seed vigor.(AU)

A salinidade é um dos fatores que promove a inibição no crescimento e produtividade vegetal, sendo necessária a busca por alternativas que auxiliem na mitigação da ação degenerativa do estresse salino às culturas. Objetivou-se com este trabalho avaliar doses de ácido salicílico na germinação e vigor de sementes de Mesosphaerum suaveolens (L.) Kuntze submetidas à salinidade. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial incompleto 5 x 5, com cinco níveis de condutividade elétrica da água de irrigação (CEa de 0,0; 1,45; 5,00; 8,55 e 10,00 dS m-1) e cinco doses de AS de (0,0; 0,29; 1,00; 1,71 e 2,00 mM L-1), com quatro repetições de 50 sementes, totalizando nove combinações geradas via matriz Composto Central de Box. As variáveis avaliadas foram: porcentagem de germinação, primeira contagem de germinação, índice de velocidade de germinação, tempo médio de germinação, porcentagem de plântulas anormais, comprimento da parte aérea, radícula e plântula e massa seca total de plântulas. O ácido salicílico atenua o efeito do estresse salino sobre o crescimento inicial, mitigando os danos sobre o comprimento de radícula e da parte aérea. O tratamento das sementes com ácido salicílico melhora a germinação e o vigor das sementes.(AU)

Morphophysiology of yellow passion fruit seedlings under application of nitrogen and potassium and irrigation with highsalinity water / Morfofisiologia de mudas de maracujazeiro amarelo sob aplicaçãode nitrogênio e potássio e irrigadas com águas salinas

Salinity is one of the most problematic abiotic stresses in agriculture globally, especially in semi-arid regions. Thus, the application of nutrients, such as nitrogen and potassium to improve plant nutritional conditions may be a viable alternative to minimize the negative effects of saline stress. Therefore, the aim of this study was to evaluate the morphophysiological behavior of yellow passion fruit seedlings under varying nitrogen and potassium doses and irrigation with salt water. The experimental design was a randomized complete block with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Design with five electrical conductivities of irrigation water (0.5, 0.98, 2.15, 3.32, and 3. 80dS m-¹) and five increasing doses of nitrogen and potassium (0.0, 29.08, 100.0, 170.92, and 200.0%). Leaf, stem, and root dry phytomass and gas exchange were evaluated 75 days after sowing. The increase in salinity had negative effects on the morphological and physiological characteristics of yellow passion fruit seedlings. The application of nitrogen and potassium positively influenced photosynthetic rate and leaf and root dry phytomasses. The application of nitrogen and potassium increased intercellular CO2 concentration and transpiration in yellow passion fruit seedlings under saline stress.

A salinidade é um dos estresses abióticos mais preocupantes na agricultura mundial, principalmente nas regiões semiáridas. Assim, a aplicação de nutrientes como nitrogênio e o potássio visando melhorar as condições nutricionais das plantas pode ser uma alternativa viável para minimizar os efeitos negativos do estresse salino. Portanto, objetivou-se avaliar o comportamento morfofisiológico de mudasd e maracujazeiro-amarelo sob doses de nitrogênio e potássio e irrigadas com águas salinas. O delineamento utilizado foi em blocos casualizados, em esquema fatorial incompleto 5x5, gerados a partir da matriz Composto Central de Box com cinco condutividades elétricas da água de irrigação (0,5; 0,98; 2,15; 3,32 e 3,80 dS m-¹) e cinco doses crescentes de nitrogênio e potássio (0,0; 29,08; 100,0; 170,92 e 200,0%). Foram avaliadas as fitomassas seca de folha, caule e raiz e as trocas gasosas aos 75 dias após a semeadura. O aumento da salinidade proporciona efeitos negativos nas características morfofisiológicas do maracujazeiro amarelo. A aplicação de nitrogênio e potássio influencia positivamente na taxa fotossintética e fitomassa seca das folhas e raiz. A aplicação de nitrogênio e potássio aumenta concentração intercelular de CO2 e transpiração de mudas de maracujazeiro-amarelo sob estresse salino.

Crescimento de Erythrina velutina willd. submetida a estresse salino e aplicação de ácido salicílico / Growth of Erythrina velutina willd. submitted to salt stress and application of salicylic acid

Erythrina velutina é uma espécie endêmica da região Nordeste do Brasil, conhecida por exibir propriedades farmacológicas e potencial madeireiro. Entretanto, seu crescimento pode ser comprometido por fatores abióticos como escassez hídrica e excesso de sais. A utilização de reguladores de crescimento como o ácido salicílico está entre os métodos usados para mitigar os efeitos negativos de estresse nos vegetais. Com isso, objetivou-se avaliar o crescimento de mudas de Erythrina velutina submetida ao estresse salino e aplicação de ácido salicílico. O delineamento utilizado foi blocos casualizados, em esquema fatorial incompleto 5x5, gerados a partir da matriz Composto Central de Box com cinco níveis de condutividade elétrica da água de irrigação (CEa= 0,5; 1,74; 4,75; 7,76 e 9,0 dS m-1) e cinco doses de ácido salicílico (AS= 0,0; 0,29; 1,0; 1,71 e 2,0 mM L-1), com quatro repetições. Foram avaliadas a altura da planta, número de folhas, diâmetro do caule, taxa de crescimento relativo e absoluto da altura e diâmetro do caule, massa seca de raiz, do caule, da parte aérea e total e o índice da qualidade de Dickson. Os dados foram submetidos à análise de variância pelo teste F, nos casos de significância foi realizada análise de egressão polinomial. A salinidade promove sérios danos ao crescimento das plantas de Erythrina velutina, sendo mais acentuado nos níveis crescentes de condutividade elétrica. A aplicação de ácido salicílico nas concentrações utilizadas não atenua os efeitos da salinidade.(AU)

Erythrina velutina is an endemic species of the Northeast region of Brazil, known for displaying pharmacological properties and potential timber. However, its growth may be compromised by abiotic factors such as water scarcity and excess salts. The use of growth regulators such as salicylic acid is among the methods used to mitigate the negative effects of stress on vegetables. The objective of this study was to evaluate the growth of Erythrina velutina seedlings submitted to saline stress and salicylic acid application. The experimental design was a randomized complete block design with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Box matrix with five levels of electrical conductivity of the irrigation water (ECw= 0.5, 1.74, 4.75, 7,76 and 9.0 dS m-1) four doses of salicylic acid (SA= 0.0, 0.29, 1.0, 1.71 and 2.0 mM L-1), with four replicates. The following evaluated plant height, leaf number, stem diameter, relative and absolute growth rate of height and stem diameter, root dry matter, stem, shoot and total leaf weight and Dickson quality index. Data were submitted to analysis of variance by the F test, in cases of significance was performed polynomial regression analysis. The salinity promotes serious damage to the growth of Erythrina velutina plants, being more pronounced in increasing levels of electrical conductivity. The application of salicylic acid at the concentrations used does not attenuate the effects of salinity.(AU)

Crescimento de Erythrina velutina willd. submetida a estresse salino e aplicação de ácido salicílico / Growth of Erythrina velutina willd. submitted to salt stress and application of salicylic acid

Erythrina velutina é uma espécie endêmica da região Nordeste do Brasil, conhecida por exibir propriedades farmacológicas e potencial madeireiro. Entretanto, seu crescimento pode ser comprometido por fatores abióticos como escassez hídrica e excesso de sais. A utilização de reguladores de crescimento como o ácido salicílico está entre os métodos usados para mitigar os efeitos negativos de estresse nos vegetais. Com isso, objetivou-se avaliar o crescimento de mudas de Erythrina velutina submetida ao estresse salino e aplicação de ácido salicílico. O delineamento utilizado foi blocos casualizados, em esquema fatorial incompleto 5x5, gerados a partir da matriz Composto Central de Box com cinco níveis de condutividade elétrica da água de irrigação (CEa= 0,5; 1,74; 4,75; 7,76 e 9,0 dS m-1) e cinco doses de ácido salicílico (AS= 0,0; 0,29; 1,0; 1,71 e 2,0 mM L-1), com quatro repetições. Foram avaliadas a altura da planta, número de folhas, diâmetro do caule, taxa de crescimento relativo e absoluto da altura e diâmetro do caule, massa seca de raiz, do caule, da parte aérea e total e o índice da qualidade de Dickson. Os dados foram submetidos à análise de variância pelo teste F, nos casos de significância foi realizada análise de egressão polinomial. A salinidade promove sérios danos ao crescimento das plantas de Erythrina velutina, sendo mais acentuado nos níveis crescentes de condutividade elétrica. A aplicação de ácido salicílico nas concentrações utilizadas não atenua os efeitos da salinidade.

Erythrina velutina is an endemic species of the Northeast region of Brazil, known for displaying pharmacological properties and potential timber. However, its growth may be compromised by abiotic factors such as water scarcity and excess salts. The use of growth regulators such as salicylic acid is among the methods used to mitigate the negative effects of stress on vegetables. The objective of this study was to evaluate the growth of Erythrina velutina seedlings submitted to saline stress and salicylic acid application. The experimental design was a randomized complete block design with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Box matrix with five levels of electrical conductivity of the irrigation water (ECw= 0.5, 1.74, 4.75, 7,76 and 9.0 dS m-1) four doses of salicylic acid (SA= 0.0, 0.29, 1.0, 1.71 and 2.0 mM L-1), with four replicates. The following evaluated plant height, leaf number, stem diameter, relative and absolute growth rate of height and stem diameter, root dry matter, stem, shoot and total leaf weight and Dickson quality index. Data were submitted to analysis of variance by the F test, in cases of significance was performed polynomial regression analysis. The salinity promotes serious damage to the growth of Erythrina velutina plants, being more pronounced in increasing levels of electrical conductivity. The application of salicylic acid at the concentrations used does not attenuate the effects of salinity.

Temperatures and substrates for germination and vigor ofErythroxylum pauferrense Plowman seeds

Erythroxylum pauferrense is an endemic understory plant species of the Northeast Region of Brazil. The species is of great importance to the region and so ecophysiological studies are needed for its preservation. The objective of the present study was to determine the best substrates and temperatures for testing germination and seed vigor of E. pauferrense. An experiment was performed comprising a completely randomized design in a 5 x 4 factorial scheme, with five temperature regimes (20, 25, 30, 35°C constant and 20-30°C alternating) and four types of substrates (paper, vermiculite, sand and commercial substrate). The following characteristics were evaluated: germination percentage, first germination count, germination speed index, mean germination time, seedling length and dry mass (root and shoot). Paper and vermiculite substrates combined with constant temperatures of 20, 25, 30 and alternated between 20-30°C, provide greater seed germination and vigor while 35°C reduces seed physiological quality.