ABSTRACT Salinity is one of the main challenges in agriculture, especially in arid and semi-arid regions. Salicylic acid application may be a strategy to mitigate the harmful effects of salt stress on plant growth. Basil (Ocimum basilicum ) is a medicinal, spice, and ornamental plant grown around the world that has its growth reduced by salt stress. Therefore, the objective was to evaluate salicylic acid in mitigating the damage caused by salt stress in ‘Cinnamon’ basil. Growth was evaluated at 90 days after the start of irrigation with saline water. Salicylic acid application attenuates the harmful effects of salt stress on the number of leaves, number of inflorescences, leaf dry mass, inflorescence dry mass, root dry mass, seed mass, leaf area, leaf area ratio, specific leaf area, leaf mass ratio, root mass ratio, inflorescence mass ratio, Dickson quality index, sclerophilia index, robustness quotient and shoot root ratio. Salt stress decreased plant height, stem diameter, stem dry mass, and stem mass ratio of basil ‘Cinnamon’. Salicylic acid can be used to lessen the harmful effects of salt stress on basil ‘Cinnamon’. agriculture semiarid semi regions Ocimum medicinal spice Therefore ‘Cinnamon Cinnamon 9 water leaves inflorescences index height diameter ‘Cinnamon. .

ABSTRACT Several abiotic factors, such as water availability, significantly affect the development of forest species found in the understory. This research aimed to evaluate morphophysiological characteristics in plants of Erythroxylum pauferrense submitted to different water regimes. The experiment was developed in a greenhouse at the Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil. The experimental design was in randomized blocks, with five water treatments [100%, 80%, 60%, 40% and 20% of the pot capacity (PC)] and four replications. Growth attributes, morphofunctional aspects, gas exchange, chlorophyll fluorescence and chlorophyll indices were evaluated. The data were submitted for analysis of variance, and in cases of significance, polynomial regression analyses were performed. The plants of Erythroxylum pauferrense submitted to 100% and 80% water levels of the PC present greater development and morphophysiological performance. In comparison, the evaluated parameters were significantly reduced in the regime of greater water stress (20% of the PC). Thus, the water regime of 80% of PC is the most recommended for producing seedlings of Erythroxylum pauferrense, promoting greater growth and significant changes in morphofunctional aspects, gas exchange, chlorophyll fluorescence and chlorophyll indexes. factors availability understory regimes Paraíba II Areia Brazil blocks 100%, 100 [100% 80 60 60% 40 20 (PC) replications attributes aspects exchange variance significance performed performance comparison (20 PC. . PC) Thus indexes 10 [100 8 6 4 2 (PC (2 1 [10 ( [1 [

RESUMO Vários fatores abióticos, como a disponibilidade de água, afetam significativamente o desenvolvimento das espécies florestais encontradas no sub-bosque. Esta pesquisa teve como objetivo avaliar características morfofisiológicas em plantas de Erythroxylum pauferrense submetidas a diferentes regimes hídricos. O experimento foi desenvolvido em casa de vegetação na Universidade Federal da Paraíba, Campus II, Areia, Paraíba, Brasil. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos hídricos [100%, 80%, 60%, 40% e 20% da capacidade do vaso (PC)] e quatro repetições. Foram avaliados atributos de crescimento, aspectos morfofuncionais, trocas gasosas, fluorescência da clorofila e índices de clorofila. Os dados foram submetidos à análise de variância e, nos casos de significância, análises de regressão polinomial. As plantas de Erythroxylum pauferrense submetidas a regimes hídricos de 100% e 80% da PC apresentam maior desenvolvimento e desempenho morfofisiológico. Em comparação, os parâmetros avaliados foram significativamente reduzidos no regime de maior estresse hídrico (20% da PC). Assim, o regime hídrico de 80% de PC é o mais recomendado para produção de mudas de Erythroxylum pauferrense, promovendo maior crescimento e alterações significativas nos aspectos morfofuncionais, trocas gasosas, fluorescência da clorofila e índices de clorofila. abióticos água subbosque. subbosque sub bosque. bosque sub-bosque Paraíba II Areia Brasil acaso 100%, 100 [100% 80 60 60% 40 20 (PC) repetições morfofuncionais gasosas significância polinomial morfofisiológico comparação (20 PC. . PC) Assim 10 [100 8 6 4 2 (PC (2 1 [10 ( [1 [

ABSTRACT Basil (Ocimum gratissimum - Lamiaceae), is a sub-shrub plant species with great economic importance for several regions, and studies on its growth, physiology, and reproduction become needed. The aimed research was to obtain a regression equation to estimate leaf area of O. gratissimum. 250 basil leaves were collected and the linear dimensions (length and width) and real leaf area of each leaf were measured. From these data, the products between length and width, length and length were calculated. Equations were obtained using regression models: linear, linear without intercept, quadratic, cubic, power, and exponential. The best equation was selected based on determination coefficient, Pearson’s correlation coefficient, Willmott’s agreement index and CS index, Akaike information criterion, mean absolute error and root mean square error. All equations proposed using the product between length and width (LW) can be used to predict the leaf area of O. gratissimum. However, the equation LA=0.54*LW1.03 (power model) is the most recommended to estimate the leaf area of this species. Ocimum Lamiaceae, Lamiaceae , Lamiaceae) subshrub sub shrub regions growth physiology needed O 25 measured data calculated models intercept quadratic cubic power exponential coefficient Pearsons Pearson s Willmotts Willmott criterion LW (LW However LA054LW103 LALW LA 0 54 LW1 03 LA=0.54*LW1.0 model 2 LA054LW10 5 LA=0.54*LW1. LA054LW1 LA=0.54*LW1 LA054LW LA=0.54*LW

ABSTRACT Ocimum basilicum L. (basil) is an annual herb belonging to the Lamiaceae family that has economic importance for many regions around the world. Thus, ecophysiological studies are needed to assess this species growth and dispersal. This work aimed to obtain equations from regression models that meaningfully estimate the leaf area of basil cultivars using linear dimensions of leaves. For this purpose, 300 leaves from 'Italiano Roxo' and 500 leaves from 'Folha Fina' cultivar were collected from plants cultivated in a greenhouse. Then, the length, width, and leaf area of each leaf were measured, and product of length by width were calculated. The equations were adjusted using the simple linear, linear without intercept, quadratic, cubic, power, and exponential regression models. Criteria for selecting the best equations were highest determination coefficient and Willmott's agreement index, lowest Akaike information criterion and root mean square error, and BIAS index closest to zero. All the equations fitted using the product of length by width (L.W) can estimate the leaf area of basil cultivars. Thus, basil leaf area can be estimated through a non-destructive method using linear dimensions of leaves. However, the equation ŷ = 0.8175*LW0.9307 is the most suitable for 'Italiano Roxo' and ŷ = 0.6335*LW for 'Folha Fina'.

ABSTRACT The determination of leaf area is fundamental for studies related to plant growth and physiology. Thus, non-destructive methods allow an accurate estimate of the leaf area through linear dimensions of the leaves. The research objective was to construct allometric equations to estimate the leaflet area of peanut cultivars. Then, 2,605 leaflets were collected from six peanut cultivars (IAC Caiapó, IAC 8112, Runner IAC 886, BRS Havana, BRS 151 L7, and IAC Tatuí), with more than 400 leaflets sampled for each cultivar. We measured the length, width, product between length and width, and leaflet area. Linear and non-linear models (linear, linear without intercept, power, and exponential) were built, and the best equation was chosen using the statistical criteria: highest coefficient of determination (R2), Pearson’s linear correlation coefficient (r), Willmott’s agreement index (d), lowest Akaike information criterion (AIC), and root mean square of the error (RMSE). It was found that the models that used the product between length and width were the most suitable for estimating the leaflet area of peanut cultivars. Given the little intraspecific morphological variability, it was possible to group the cultivars, and model y ^ = 0.875 * LW0.929 was indicated to estimate the peanut leaflet area accurately, regardless of the cultivar.

Abstract Climatic variation throughout the day influences the ecophysiological performance of plants at different growth stages and phases. Therefore, this work aimed to evaluate the effect of climatic variation on ecophysiological aspects of T. roseoalba and H. heptaphyllus at different hours of the day and indicate the ideal time for measuring ecophysiological variables in these species. The research was carried out in a greenhouse at the forest nursery of the Federal University of Paraíba, Campus II, in the municipality of Areia, Paraíba state, Northeastern Brazil. The experimental design was completely randomized, consisting of 10 evaluation times throughout the day (from 8 am to 5 pm), with 1 h hour interval between each evaluation. Temperature and air relative humidity inside and outside the greenhouse were evaluated to understand the effect on gas exchange (net assimilation rate of CO2, stomatal conductance, transpiration rate, internal concentration of CO2, and vapor-pressure deficit) and chlorophyll a fluorescence (initial, maximum, and variable fluorescence, photochemical quenching, and electron transport rate). Data were submitted to canonical correlation analysis and principal component analysis to verify the relationship between climatic and ecophysiological variables. For both species, higher correlation was found between internal and external relative humidity with all the ecophysiological variables analyzed, except for initial fluorescence. Thus, climatic factors influenced the photosynthetic performance of T. roseoalba and H. heptaphyllus plants, and 8 am to 9 am is indicated for carrying out ecophysiological evaluations in both species.

Resumen El agua en las regiones semiáridas contiene sales en exceso. Cuando no se dispone de agua de buena calidad, es necesario utilizar estrategias que permitan el uso de agua salina. El objetivo de este estudio fue evaluar los efectos de la aplicación del regulador del crecimiento vegetal en el cultivo de albahaca bajo estrés salino. El experimento se llevó a cabo en un diseño de bloques al azar, en la matriz “Compuesto Central de Box”. Se evaluó la altura de la parte aérea, el diámetro del tallo, el área de la hoja, las masas secas y las características químicas del suelo. La salinidad del agua de riego provoca la reducción de los parámetros de crecimiento de la albahaca, con la excepción de la masa seca de inflorescencia. Las aplicaciones del regulador del crecimiento vegetal tienen efecto sobre el crecimiento de la albahaca cuando las plantas se riegan con agua salina.

Abstract The water in semiarid regions contains salts in excess. When good quality water is not available it is necessary to use strategies that can make feasible the use of saline water. The aim of this study was to evaluate the effects of the application of the plant growth regulator on the culture of basil stressed with salt. The experiment was carried out in a randomized block design by the matrix “Central Box Compound”. Shoot height, stem diameter, leaf area, dry masses and soil chemical characteristics were evaluated. The salinity of the irrigation water causes reduction of the basil growth parameters, with the exception of the inflorescence dry mass. Plant growth regulator applications have effect on basil growth when plants are irrigated with saline water.

Abstract The aim of this study was to evaluate the initial growth of Agonandra brasiliensis Miers ex Benth. & Hook. F. in response to different levels of shading and doses of controlled-release fertiliser (CRF). The experiment was conducted at Embrapa Roraima in Boa Vista, in a completely randomised experimental design and a 2 x 5 factorial scheme, of two luminosity levels (50 and 30%) and five doses of CRF (formulation 18-05-09, NPK) (0, 0.5, 1, 2 and 3 g L-1 substrate), with five replications, each consisting of five plants. At 240 days after transplanting, the growth characteristics were evaluated, and the influence of the light levels and the CRF dose was recorded on these characteristics, either individually or interactively. It is suggested that plants of Agonandra brasiliensis be fertilised with a dose of 2 g L-1 CRF and grown in an environment with 50% of luminosity to maximize growth and efficiency in the production of high-quality seedlings.

ABSTRACT Bell pepper (Capsicum annuum) is one of the most consumed vegetables around the world. Balanced fertilization is essential for growing this vegetable. The objective of this study was to evaluate the yield and morphological attributes of bell pepper under doses and times of application of biological fertilizers. Two experiments were carried out with applications of biological fertilizers prepared from manure and enriched organic compounds with cattle manure and sheep manure. The experimental design was a randomized complete block design, in a 4 x 3 + 1 factorial scheme, with three replications, referring to doses of biological fertilizers (100, 200, 300 and 400 L ha-1), times of application (0, 30 and 60 days after transplanting - DAT) and control. The evaluated variables were: total fruit weight (TFW), number of commercial fruits (NCF), number of non-commercial fruits (NNCF), fruit weight (FW), fruit diameter (FD), fruit length (FL), resistance of fruit peel (RFP), number of flower buds (NFB) and productivity (P). Biological fertilizers caused positive effects on TFW, NCF, FW and P of bell pepper. The application of cattle manure at 60 DAT and sheep manure at 30 DAT promoted a larger fruit diameter. The FW, FL and RFP were influenced by the doses and times of application of biological fertilizers. The application of biofertilizers is efficient in the production of bell pepper.

RESUMO Agonandra brasiliensis é uma árvore de florestas tropicais, com ampla ocorrência na região do Cerrrado brasileiro. Apesar do seu potencial como madeira e para reflorestamento, eficientes protocolos para a produção de mudas ainda estão em falta. Objetivou-se avaliar características morfológicas para a qualidade de mudas de A. brasiliensis, em condições de viveiro, em função do volume do recipiente e dose de fertilizante de liberação controlada. O experimento foi realizado em esquema fatorial 2 x 5, testando-se dois volumes (1,8 L e 2,2 L) de recipiente e cinco doses (0 g L-1, 1 g L-1, 2 g L-1, 4 g L-1 e 8 g L-1) do fertilizante encapsulado Forth Cote® (formulação NPK 15-09-12). As parcelas constituíram-se de cinco mudas homogêneas transplantadas em sacos de polietileno (15 cm x 35 cm) com substrato de areia média lavada. As seguintes características foram mensuradas: comprimento da parte aérea; diâmetro do caule; incrementos em comprimento e diâmetro; matéria seca total; matéria seca da parte aérea e da raiz e a razão entre elas. Também foi determinado o Índice de Qualidade de Dickson. A qualidade das mudas para caracteres morfológicos como comprimento da parte aérea, diâmetro de caule e matéria seca total foi especialmente favorecida por tratamentos que combinaram o fertilizante de liberação controlada em dose aproximada de 5,0 g L-1 e recipiente com volume de 2,2 L.

ABSTRACT Agonandra brasiliensis is a tree from tropical forests, with a wide occurrence in the Brazilian Savannah region. Despite its potential as wood and for reforestarion, efficient protocols for its seedling production are still lacking. This study aimed to assess morphological characteristics for the seedling quality of A. brasiliensis, under nursery conditions, as a function of container volume and controlled-release fertilizer dose. The experiment was carried out in a 2 x 5 factorial scheme, testing two container volumes (1.8 L and 2.2 L) and five doses (0 g L-1, 1 g L-1, 2 g L-1, 4 g L-1 and 8 g L-1) of the encapsulated fertilizer Forth Cote™ (formulation NPK 15-09-12). The plots consisted of five homogeneous seedlings transplanted in polyethylene bags (15 cm x 35 cm) with washed medium sand substrate. The following characteristics were measured: shoot length; stem diameter; increases in length and diameter; total dry matter; shoot and root dry matters and the ratio between them. The Dickson Quality Index was also obtained. The seedling quality for morphological traits, such as shoot length, stem diameter and total dry matter, was especially favoured by treatments combining the controlled-release fertilizer at a dose around 5.0 g L-1 and container volume of 2.2 L.

Resumen Maracujá-do-mato (Passiflora cincinnata) es una especie adaptada a las condiciones climáticas de la región semiárida brasileña y ampliamente utilizada como portainjertos, sin embargo, los estudios relacionados con la producción de plántulas y su resistencia a estrés abióticos son escasos en la literatura. El objetivo de este estudio fue medir la producción de plántulas de maracuyá bajo el efecto de la conductividad eléctrica en el agua de riego en función de la aplicación de fertilizantes orgánicos. El experimento se desarrolló en la Universidade Estadual da Paraíba, Catolé do Rocha-PB, Brasil, en un diseño experimental completamente aleatorizado, en un esquema factorial de 5 x 3, con seis replicaciones. Los factores evaluados fueron cinco conductividades eléctricas de agua de riego (ECw: 1; 2; 3; 4 y 5 dS m-1) y la aplicación de tres fertilizantes orgánicos (orina de bovino, biofertilizante bovino y humus de lombriz líquida). Se encontró que el aumento de ECw afectó negativamente la morfología y la calidad de las plántulas, mientras que el biofertilizante bovino presentó una mayor eficiencia en comparación con los demás tratamientos. Se concluye que el uso de fertilizantes orgánicos como efectos atenuantes de la salinidad es una estrategia para la producción de plántulas de pasiflora en condiciones de suelos salinos.

Abstract Maracujá-do-mato (Passiflora cincinnata) is a species adapted to the climatic conditions of the Brazilian semi-arid region and widely used as rootstock, however, studies related to the production of seedlings and their resistance to abiotic stresses are scarce in literature. The objective was to study the production of maracujá-do-mato seedlings under the effect of the electrical conductivity on the irrigation water as a function of the application of organic fertilizers. The experiment was developed at the Paraíba State University, Catolé do Rocha-PB, in a completely randomized experimental design, in a 5 x 3 factorial scheme, with 6 replicates. The factors evaluated were five electrical conductivities of irrigation water (ECw: 1; 2; 3; 4 and 5 dS m-1) and application of three organic fertilizers (bovine urine, bovine biofertilizer and liquid earthworm humus). It was verified that the increase of ECw affected the morphology and the quality of the seedlings negatively, while the bovine biofertilizer presented better efficiency in comparison to the others. It is inferred that the use of organic fertilizers as mitigating effects of salinity may be a strategy for production of maracujá-do-mato seedlings in saline conditions.

Um experimento foi conduzido a céu aberto no município de Remígio, PB, para se avaliar as respostas do maracujazeiro amarelo relacionadas à eficiência fotossintética e trocas gasosas. O delineamento experimental utilizado foi em blocos casualizados, no esquema fatorial 2 x 2 x 2, referente à irrigação com água não salina (0,5 dS m-1) e salina (4,5 dS m-1), sem e com biofertilizante bovino, sem e com cobertura morta, com três repetições e três plantas por parcela, em recipientes plásticos circulares utilizados como lisímetros de pressão, com 130 dm³ de volume e drenos na parte inferior para a lixiviação do excesso de sais. A irrigação com água de baixa salinidade e aplicação de biofertilizante bovino comum estimularam a eficiência fotossintética das plantas. O uso simultâneo de água de alta salinidade, biofertilizante e cobertura morta reduziram a condutância estomática do maracujazeiro amarelo. As plantas sob estresse salino apresentaram atividade fotoquímica do fotossistema II e fotossíntese líquida inibida.

The experiment was conducted in Remigio, Paraiba State, to evaluate the responses of yellow passion fruit (Passiflora edulis Sims f. flavicarpa Degener) related to photosynthetic efficiency and gás exchange, mineral nutrition, water consumption yield and water use efficiency by plants. The experimental design was randomized blocks in a 2 x 2 x 2 factorial, related to irrigation with not saline (0.5 dS m-1) and saline water (4.5 dS m-1), soil with and without biofertilizer, with and without mulch, in three replications. Three plants were maintained in plastic containers used as pressure circular lysimeters with 130 dm³ volume and drains to the leaching of salts excess. Irrigation water with low salinity and application of biofertilizer common stimulated photosynthetic efficiency of plants. Simultaneous use of high salinity water, fertilizer and mulch to reduced stomatal conductance of yellow passion fruit. Plants under salt stress have photochemical activity of photosystem II and inhibited net photosynthesis.

The experiment was conducted in field in the municipaly Remigio, state of the Paraiba, Brazil, to evaluate the effects of the use of saline water for irrigation, bovine biofertilizer and mulch on the chemical characteristics of the fruits of yellow passion fruit. The experimental design was completely randomized in a factorial 2 x 2 x 2, three replications and three plants per experimental unit. Study material consisted of irrigation with water is not saline (0.50 dS m-1) and saline (4.50 dS m-1), with and without application of bovine biofertilizer, with and without mulch. The use of bovine biofertilizer reduced the negative action of the salts, increasing the pH, soluble solids and vitamin C in fruits of yellow passion fruit. The veal and mulching biofertilizer did not affect the titratable acidity values in passion fruit with an increased salt content of water. The content of vitamin C in fruits did not change with the use of mulch and biofertilizer veal. The ratio soluble solids / acidity of the passion fruit was reduced with the use of organic inputs and soil cover by applying saline water for irrigation of plants. The increasing salinity of irrigation water increased the electrical conductivity of the juice, regardless of the application of fertilizer and use of mulch.

El experimento se realizó en campo experimental del municipio de Remigio, estado de la Paraíba, Brasil, con el objetivo de evaluar los efectos del uso de agua salina en el riego, biofertilizante bovino y mantillo en las características químicas de los frutos del maracuyá amarillo. El diseño experimental fue de tres bloques al azar, con un arreglo factorial de 2 x 2 x 2, tres repeticiones y tres plantas por unidad experimental, los factores evaluados fueron: agua de riego no salina (0,50 dS m-1), salina (4,50 dS m-1), con o sin aplicación de biofertilizante bovino, con o sin mantillo. El uso de biofertilizante bovino redujo la acción negativa del sal, pH, sólidos solubles y los niveles de vitamina C en el fruto de maracuyá amarillo. El biofertilizante bovino y el mantillo no influyeron en los valores de acidez titulable del maracuyá amarillo con el aumento del contenido de sal en el agua. El porcentaje de vitamina C en los frutos no cambió con el uso de mantillo y biofertilizante bovino. La razón de sólidos solubles y acidez titulable del maracuyá amarillo se redujo con el uso del insumo orgánico y mantillo al aplicar agua salina en el riego de las plantas. El aumento en la salinidad del agua de riego aumentó la conductividad eléctrica del jugo independientemente de la aplicación del biofertilizante y el uso del mantillo.

The size and yield of fruit are important in the physical quality of the fruits destined for markets and industry. An experiment was performed to evaluate the form, peel strength and yield of fruits of yellow passion fruit plant produced in substrata with bovine bio-fertilizer and mulching, irrigated with saline water. The treatments were designed in three random blocks using a 2 x 2 x 2 factorial arrangement; irrigation with non-saline (0.50 dS m-1) and saline (4.50 dS m-1) water, with and without application of bovine biofertilizer and with and without mulching. The passion fruit fruits were harvested when 30% of the peel was yellowish; we evaluated the diameter of the longitudinal cavity (length), diameter of the equatorial cavity (width), fruit form index, peel strength and juice and pulp yield. The substrate with bovine bio-fertilizer and mulching irrigated with high salinity water reduced the diameter of the longitudinal and equatorial cavity, the fruit form index and increased the firmness of the peel of the fruits of the yellow passion fruit plant. However, the use of the bovine biofertilizer and mulching irrigated with non-saline water increased the diameter of the equatorial and longitudinal cavity and the fruit form index.

Las dimensiones y el rendimiento de los frutos son características fundamentales para la calidad de frutos destinados al mercado y la industria. En este sentido se realizó un experimento para evaluar el formato, resistencia y rendimiento de maracuyá amarillo producido en sustrato con biofertilizante bovino, mantillo e irrigado con agua salina. El diseño experimental fue de tres bloques al azar, con un arreglo factorial de 2 x 2 x 2, los factores evaluados fueron: agua de riego no salina (0,50 dS m-1), salina (4,50 dS m-1), con aplicación y sin aplicación de biofertilizante bovino, con y sin mantillo. Los frutos de maracuyá fueron cosechados con 30% de corteza amarillenta y se evaluó el diámetro de la cavidad longitudinal (largura), diámetro de la cavidad ecuatorial (transversal), índice de formato de los frutos, resistencia de la cáscara y rendimiento de jugo y pulpa. Los mayores valores de diámetro de la cavidad longitudinal, diámetro de la cavidad ecuatorial, índice de formato de los frutos y rendimiento de jugo y pulpa se obtuvieron con el uso de biofertilizante bovino y mantillo en los sustratos regados con agua de alto nivel de salinidad. El uso de agua de alto nivel de salinidad redujo el diámetro de la cavidad longitudinal, el diámetro de la cavidad ecuatorial, el índice de formato de los frutos, independientemente de la presencia de insumos orgánicos en el sustrato y aumentó el rendimiento de jugo, pulpa y resistencia de la cáscara en los tratamientos sin biofertilizante y sin mantillo. El mayor índice de formato del fruto presentó el mayor rendimiento de jugo.

Os efeitos deletérios provocados pelo estresse salino resultam em modificações nos mecanismos bioquímicos e fisiológicos das plantas, alterando, dentre outros, os teores foliares de clorofila e carotenoides, comprometendo a atividade fotossintética e, consequentemente, o crescimento, o desenvolvimento, a produção e a adaptabilidade aos ambientes adversos. O objetivo do trabalho foi avaliar os efeitos de diferentes condutividades elétricas da água de irrigação (CEai), associadas às épocas de aplicação de biofertilizante, sobre os teores de pigmentos fotossintéticos para a determinação dos pigmentos cloroplastídicos (clorofila a, b, total e carotenoides) do maracujazeiro-amarelo. Os tratamentos foram distribuídos em arranjo fatorial 5 x 4, referentes aos valores de CEai: 0,5; 1,5; 2,5; 3,5 e 4,5 dS m-1, em quatro épocas de aplicação do biofertilizante: sem biofertilizante (SB); aplicação uma semana antes do transplantio (1SAT); a cada 90 dias, a partir do transplantio (90DAT); uma semana antes e a cada 90 dias, após o transplantio (1SAT+90DAT). O aumento da concentração salina da água de irrigação reduziu a eficiência fotossintética nas folhas do maracujazeiro-amarelo, sendo mais drástico na condutividade superior a 2,5 dS m-1. As frequências de aplicação do biofertilizante não influenciaram nas concentrações dos pigmentos fotossintéticos.

The deleterious effects caused by salt stress result in changes in the physiological and biochemical mechanisms of plants, changing, among others, the levels of chlorophyll and carotenoids, affecting the photosynthetic activity and hence growth, development, production and adaptability to adverse environments. The study aimed to evaluate the effects of irrigation water with increasing salinity levels and the application frequency of biofertilizer on the concentration of the photosynthetic pigments (chlorophyll a, b, total and carotenoids) of the yellow passion fruit. The experiment was designed in a 5 x 4 factorial corresponding to the levels of electrical conductivity (EC) of the irrigation water of 0.5; 1.5; 2.5; 3.5 and 4.5 dS m-1 and to four frequencies of the application of bovine biofertilizer: no biofertilizer (WB); application of bovine biofertilizer one week before transplanting (1WBT); bio-fertilizer application every 90 days after transplanting (90DAT); and bovine bio-fertilizer applied one week before and every 90 days after transplanting (1WBT+90DAT). Increased salinity of irrigation water reduced the photosynthetic efficiency in leaves of yellow passion fruit, being more drastic in the conductivity above 2.5 dS m-1. The frequency of application of biofertilizer did not influence the photosynthetic pigments content.