In the Brazilian semiarid region, the occurrence of water sources with high salt concentrations stands out as a limiting factor for the production of most crops under irrigated conditions. This research was conducted to evaluate the physical and chemical quality of sour passion fruit as a function of brackish water irrigation strategies and potassium doses. The experiment was carried out under field conditions using a randomized block design in a 6 × 2 factorial scheme, consisting of six strategies of irrigation with brackish water (irrigation with water of 1.3 dS m-1 throughout the cycle - WS; irrigation with water of 4.0 dS m-1 in the vegetative stage - VE; flowering stage - FL; fruiting stage - FR; in the successive vegetative/flowering stages - VE/FL; vegetative/fruiting stages - VE/FR) and two potassium doses: 60 and 100% (345 g of K2O per plant per year) of recommendation, with four replicates and three plants per plot. Irrigation with water of 4.0 dS m-1 in the flowering stage or continuously in the vegetative and flowering stages reduced the yield and size of sour passion fruit. Fertilization with 60% of K is recommended for the production of sour passion fruits with greater polar diameter. It is feasible to cultivate sour passion fruit under irrigation with 4.0 dS m-1 of water in the flowering and fruiting stages and fertilization with 60% of the K recommendation without losses in ascorbic acid and total soluble sugars.

The objective of this study was to evaluate the physiological indices of sour passion fruit under brackish water irrigation strategies and potassium fertilization. The study was carried out under field conditions in São Domingos, PB, Brazil, using a randomized block design in a 6 × 2 factorial scheme, with treatments consisting of six brackish water irrigation strategies (irrigation with moderately saline (1.3 dS m-1) water throughout the crop cycle - WS; irrigation with high-salinity (4.0 dS m-1) water in the vegetative stage - VE; flowering stage - FL; fruiting stage - FR; successively in the vegetative/flowering stages - VE/FL; and vegetative/fruiting stages - VE/FR) and two doses of potassium (207 and 345 g K2O per plant per year, corresponding, respectively, to 60 and 100% of recommendation), with four replicates and three plants per plot. Irrigation with water of 4.0 dS m-1 reduced the osmotic and water potentials in the leaf blade, synthesis of chlorophylls a and b, transpiration, and instantaneous carboxylation efficiency of sour passion fruit, regardless of the development stage. Salt stress in the vegetative, flowering, fruiting, and successively in the vegetative/flowering and vegetative/fruiting stages increases intercellular electrolyte leakage in sour passion fruit. Fertilization with 100% of the K recommendation increased stomatal conductance, CO2 assimilation rate, and instantaneous water use efficiency of sour passion fruit cv. BRS GA1 under irrigation with water of 1.3 dS m-1 throughout the crop cycle.

This study was carried out with the objective of evaluating the water relations, photosynthetic pigments and growth of passion fruit cv. BRS Rubi do Cerrado, as a function of the cationic nature of irrigation water and exogenous application of hydrogen peroxide. The experiment was carried out under greenhouse conditions in Pombal – PB, Brazil. The experimental design was randomized blocks, in a 6 × 4 factorial scheme, corresponding to six cationic nature of water - CNW (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Na++Ca2+; S5 - Mg2+ and S6 - Na++Ca2++Mg2+) and four concentrations of hydrogen peroxide - H2O2 (0, 20, 40 and 60 μM), distributed in a randomized block design with four replicates. Plants in the control treatment (S1) were irrigated using water with electrical conductivity (ECw) of 0.3 dS m-1, while those of the other treatments (S2; S3; S4; S5 and S6) were subjected to ECw of 3.0 dS m-1, prepared with different cation(s). Application of 60 μM of H2O2 reduced the percentage of intercellular electrolyte leakage in plants irrigated with water of calcic composition. Salinity of water composed of sodium, sodium+calcium and sodium+calcium+magnesium, and H2O2 concentrations of 40 and 60 μM resulted in lower leaf water potential. The biomass accumulation of passion fruit was more sensitive to the variation of the electrical conductivity of the water. Regardless of the cationic nature, the use of water with electrical conductivity of 3.0 dS m-1 produced passion fruit seedlings with a Dickson quality index higher than 0.2, considered acceptable.

DANO CELULAR E PIGMENTOS FOTOSSINTÉTICOS DO MARACUJAZEIRO-AZEDO EM FUNÇÃO DA NATUREZA CATIÔNICA DA ÁGUA   GEOVANI SOARES DE LIMA1; WESLLEY BRUNO BELO DE SOUZA2; LAURIANE ALMEIDA DOS ANJOS SOARES3; FRANCISCO WESLEY ALVES PINHEIRO4; HANS RAJ GHEYI5 E VALESKA KAROLINI NUNES OLIVEIRA6   1 Unidade Acadêmica de Engenharia Agrícola, Universidade Federal de Campina Grande, UFCG, Rua Aprígio Veloso, 882 - Universitário, Campina Grande, PB, Brasil. E-mail: geovani.soares@p             q.cnpq.br. 2 Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, UFCG, Rua Jario Vieira Feitosa, 1770, Bairro dos Pereiros, Pombal, PB, Brasil. E-mail: weslleybruno96@hotmail.com. 3 Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, UFCG, Rua Jario Vieira Feitosa, 1770, Bairro dos Pereiros, Pombal, PB, Brasil. E-mail: lauriane.soares@pq.cnpq.br. 4 Unidade Acadêmica de Engenharia Agrícola, Universidade Federal de Campina Grande, UFCG, Rua Aprígio Veloso, 882 - Universitário, Campina Grande, PB, Brasil. E-mail: wesley.ce@hotmail.com.  5Unidade Acadêmica de Engenharia Agrícola, Universidade Federal de Campina Grande, UFCG, Rua Aprígio Veloso, 882 - Universitário, Campina Grande, PB, Brasil. E-mail: hgheyi@gmail.com. 6 Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, UFCG, Rua Jario Vieira Feitosa, 1770, Bairro dos Pereiros, Pombal, PB, Brasil. E-mail: valeska.karoline2015@gmail.com.     1 RESUMO   Este trabalho teve como objetivo de avaliar o dano celular e os teores de pigmentos fotossintéticos do maracujazeiro-azedo em função da natureza catiônica da água de irrigação. O experimento foi desenvolvido sob condições de casa-de-vegetação em Pombal-PB. O delineamento experimental foi o de blocos casualizados, sendo os tratamentos constituídos de seis natureza catiônica da água (S1-Testemunha; S2 - Na+; S3 - Ca2+; S4 - Na+ + Ca2+; S5 - Mg2+ e S6 - Na+ + Ca2+ + Mg2+), distribuídos em delineamento de blocos ao acaso com quatro repetições, sendo a parcela constituída de duas plantas. As plantas do tratamento testemunha (S1) foram irrigadas com água de condutividade elétrica (CEa) de 0,3 dS m-1 e as demais (S2; S3; S4; S5 e S6) foram cultivadas com CEa de 3,0 dS m-1. A irrigação com água de composição Na+ e Na+ + Ca2+ resultou em maior dano celular nos tecidos foliares. A síntese de clorofila a foi inibida pela salinidade de natureza Mg2+ e Na+ + Ca2+ + Mg2+. A salinidade da água afetou negativamente os teores de clorofila b do maracujazeiro-azedo. O uso de água com composição sódica induziu aumento na síntese de carotenoides em plantas de maracujazeiro-azedo.   Palavras-chave: Passiflora edulis Sims, estresse salino, semiárido.     LIMA, G. S. de; SOUZA, W. B. B. de; SOARES, L. A. dos A.; PINHEIRO, F. W. A.; GHEYI, H. R.; OLIVEIRA, V. K. N. CELL DAMAGE AND PHOTOSYNTHETIC PIGMENTS OF THE SOUR PASSION FRUIT IN FUNCTION OF THE CATIONIC NATURE OF WATER         2 ABSTRACT   This study had the objective of evaluating the cellular damage and the levels of photosynthetic pigments of the sour passion fruit in function of the cationic nature of the irrigation water. The experiment was conducted under greenhouse conditions in Pombal -PB. The experimental design was randomized blocks, with treatments consisting of six cationic nature of water (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Na++ Ca2+; S5 - Mg2+ and S6 - Na++ Ca2++ Mg2+), distributed in a randomized block design with four replications, and each plot consisting of two plants. The plants of the control treatment (S1) were irrigated with water of electrical conductivity (ECw) of 0.3 dS m-1 while those of the other (S2; S3; S4; S5 and S6) were cultivated with ECw of 3.0 dS m-1. Irrigation with Na+ and Na++ Ca2+ water resulted in greater cellular damage in the leaf tissues. The synthesis of chlorophyll a was inhibited by salinity of Mg2+ and Na++ Ca2++ Mg2+. The salinity of the water negatively affected the chlorophyll b content of the sour passion fruit. The use of water with sodium composition induced an increase in the synthesis of carotenoids in sour passion fruit plants.   Keywords: Passiflora edulis Sims, saline stress, semiarid.

Given the quantitative scarcity of low-salinity water resources in the Brazilian semi-arid region, it is necessary to use water with a high concentration of salts. Thus, identifying salt-stress tolerant cultivars of crops is an alternative for expanding irrigated agriculture. The objective of this study was to evaluate the tolerance of passion fruit cultivars as a function of irrigation water electrical conductivity. The experimental design was randomized blocks, in a 5 × 3 factorial scheme, whose treatments consisted of the combination of five values of electrical conductivity of irrigation water - ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1) and three sour passion fruit cultivars (BRS GA1, BRS SC1, and SCS437, with three replicates. Electrical conductivity of water from 0.3 dS m-1 reduces the relative water content, gas exchange, and the number of fruits and increased electrolyte leakage in the leaf blade of passion fruit plants, at 153 days after transplantation. The passion fruit cultivars BRS GA1, BRS SC1, and SCS437 were classified as sensitive, with threshold electrical conductivity of water of 0.3, 1.0, and 0.3 dS m-1, respectively.