During initial plant development stage, an experiment was conducted to evaluate the balance of salts in the substrate used for the production of 10 hybrids from the cross between ‘Sunki’ mandarin (TSKC) and ‘Swingle’ citrumelo (CTSW), all with potential to be used as rootstock. ‘Rangpur Santa Cruz’ lime, ‘Sunki Tropical’ mandarin and the hybrid LVK (‘Volkamer’ lemon) x LCR (‘Rangpur’ lime) - 038 were included as controls, totaling 13 genotypes. Substrate samples were collected in the experiment conducted in a greenhouse at the Federal University of Campina Grande, Campus of Pombal, from December 2015 to June 2016. Two levels of irrigation water salinity were tested, using a 2 x 13 factorial scheme, with 4 replicates. The substrate was a mixture of vermiculite, pine bark and humus (1:1:1). For the salinity level of 3 dS m-1, the substrate is less salinized when cultivated with the hybrids TSKC x CTSW - 044, TSKC x CTSW - 045, TSKC x CTSW - 048, TSKC x CTSW - 049 and ‘Rangpur Santa Cruz’ lime. On the other hand, highest salt concentration was obtained in the substrate cultivated with TSKC x CTSW - 042, TSKC x CTSW - 047, TSKC x CTSW - 048, TSKC x CTSW - 053, TSKC x CTSW - 055 and TSKC x CTSW - 057.

The salinity in irrigation water is one of the most important causes to decline cultivated plants yield. The H2O2 application has shown efficiency as a stimulator and activator for antioxidative defense system in plants submitted to biotic and abiotic stresses. The objective of this study was to evaluate methods for hydrogen peroxide application as a strategy to minimize the effects of saline stress on melon plants. The experiment was designed in complete randomized blocks and set in 2 × 4 factorial scheme, consisting two levels for irrigation water salinity (S1 = 0.3 and S2 = 2.0 dS m-1) and four methods for hydrogen peroxide application (15 mM), (T1 = no peroxide application, T2= imbibition of seeds, T3 = at sowing, T4 = Foliar spraying), with five repetitions. It was evaluated the following variables at 58 days after transplanting: plant height, stem diameter, number of leaves, number of flowers, shoot dry mass, root dry mass and total dry mass. The results showed that salinity affected the growth, biomass accumulation and plant quality severely, with the highest losses promoted by the electrical conductivity of 2.0 dS m-1.

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Objective: In order to evaluate the quality of Tahiti acid lime fruits grafted on rootstocks under saline waters. Experimental Design: The experiment was set up using a randomized block design, corresponding to ten citrus combinations, relative to Tahiti acid lime grafted on ten genotypes, and two levels of saline water used in irrigation.

RESUMO:Objetivou-se avaliar o comportamento fisiológico de híbridos da tangerineira 'Sunki Comum' com o citrumelo 'Swingle', considerados tolerantes, sob salinidade da água de irrigação durante a fase de formação de porta-enxerto. O experimento foi conduzido sob condições de ambiente protegido na Universidade Federal de Campina Grande, campus de Pombal, usando-se blocos casualizados, sendo os tratamentos formados a partir de um esquema fatorial (2 x 13), relativos a dois níveis de salinidade da água de irrigação e treze genótipos de porta-enxerto, com início do estresse aos 90 e perdurando até os 210 dias após semeadura (DAS). Avaliou-se as trocas gasosas e a fluorescência da clorofila a, de posse desses dados, foram quantificadas a eficiência no uso da água (EUA) ( PALAVRAS-CHAVE:Água salina, genótipo e trocas gasosas. PHYSIOLOGICAL BEHAVIOR OF HYBRIDS OF MANDARIN WITH SWINGLE UNDER STRESS SALINO SUMARY:In order to evaluate the physiological behavior 'Sunki Comum' mandarin with 'Swingle' citrumelo considered tolerant, under saline water during the rootstock formation. The experiment was realized in greenhouse, at