Saline stress is a frequent phenomenon in the arid and semi-arid regions of the globe, affecting the agricultural production of these regions, and it is necessary to use strategies that minimize the impacts of saline stress under agriculture. This requires the incorporation of species, variety and genotypes tolerant to increase agricultural production in those regions. This study aimed to evaluate germination and initial growth of cowpea genotypes under salt stress. The experimental design was completely randomized in 19 x 3 factorial scheme, composed of nineteen cowpea cultivars and three osmotic potentials, with four replicates of 50 seeds each. The germination test lasted for eight days, when the seeds were evaluated for germination percentage, germination speed index, length of shoot and root, accumulation of dry mass of shoot and root. The increase in salinity affected germination and initial growth of the cowpea genotypes. The genotypes 6 -MNCO2-689F-2-8, 10 -MNCO2-675F-4-10, 12 -MNCO3-737F-5-9, 16 -MNCO2-677F-2, 18 -BRS-Pajeú and 19 -Paulistinha exhibited higher tolerance to salt stress in the stage of germination and initial growth. The genotypes 11 -MNCO2-675F-9-5, 13 -BRS-Tumucumaque, 15 -MNCO3-736F-7 and 17 -BR17-Gurgueia were more susceptible to the effects of salt stress in the stage of germination and initial growth.

Currently there is a great need for reuse of water in agricultural activity, aiming at reducing environmental impacts and production costs. The objective of this study was to evaluate the fruit production of hybrid Satrapo bell pepper, under fertilization with yellow water and cassava wastewater. The experiment was conducted in a greenhouse located at Campina Grande city, PB. The experimental design was completely randomized, with eight treatments and five replications, totaling 40 experimental plots. The treatments were characterized by fertilization with cattle manure (EB); NPK; human urine (HU); cassava wastewater (M); cassava wastewater and human urine (UH+M); the double volume of human urine (2xUH); the double volume of cassava wastewater (2xM); and the double volume of human urine and cassava wastewater (2xUH+M). At 60 day after transplanting (DAT) were evaluated the diameter, thickness of mesocarp, fresh and dry phytomass and number of lobes of yellow bell pepper fruits.According to the results, there were significant differences in the variables analyzed due to the treatments applied. The treatment corresponding to 2xM provided the highest results for length, diameter, thickness of the mesocarp, fresh and dry phytomass of the bell pepper fruits. On the contrary, 2xUH was the treatment that provided the lowest values for these variables and provided the highest number of lobes.

The adequate water supply and nitrogen in the soil is essential for the growth and development of plants. Sunflower is the target of several studies of such factors due to the economic importance and the needs to expand in the semi-arid regions of Brazil. This work aimed to evaluate the growth variables, measured at 80 days after sowing (DAS), and the biomass obtained at 100 DAS of the Helio 253 sunflower hybrid under the effect of nitrogen and water levels. The experiment was conducted in a greenhouse in the city of Campina Grande-PB, in split-plot of a completely randomized design with four moisture levels in the soil (50, 75, 100 and 125% of available water) and four nitrogen rates (30, 60, 90 and 120 kg ha -1 ). Among all levels of available water in the soil, the stem diameter (SD) ranged from 13.6 to 19.6 mm and the plant height (PH) from 93 to 107 cm. Plants with 100% AW showed a leaf area (LA) 45% greater than the treatment with higher water stress. The heads had an average diameter between 83 and 98 mm, the dry biomass of the heads (DBC) and total dry biomass (TDB) ranged from 45 to 55 g and of 65 to 101 g, respectively. The weight of a thousand seeds per head (W1000) obtained minimum and maximum of 49 and 66 g. The stem diameter ranged between 14.4 to 18.3 mm and the minimum and maximum plant height values were 93 and 110 cm, using applied N levels. The leaf area varied from 22 to 36 dm 2 and the heads had average diameter of 86 to 99 mm. With respect to the dry biomass of the heads, there was a variation of 38 to 68 g and TDB of 68 to 107 g and W1000 valued between 52 and 65 g under doses of N. There is considerable variation in all variables mainly due to increased water level in the soil and nitrogen fertilization.

The ornamental sunflower has great importance in the floriculture sector due to the color and vitality of its flowers. However, the production and quality of flowers decrease under salt stress, which can be mitigated with paclobutrazol application. The objective of the present study was to evaluate the effects of different application methods of paclobutrazol in ornamental sunflower ‘Sol Noturno’ irrigated with brackish waters. The experimental design was randomized blocks arranged in a 5 × 3 factorial scheme, corresponding to five electrical conductivities of irrigation water - ECw (0.4; 1.9; 3.4; 4.9, and 6.4 dS m-1) and three paclobutrazol application methods (foliar application, via soil and a control treatment - without paclobutrazol), with four replicates. The increase in salinity of irrigation water reduced gas exchange, photosystem II photochemical efficiency, SPAD index, plant height, and chapter diameter. The paclobutrazol application via soil or foliar increased stomatal conductance and transpiration by 21.09 and 17.80%, respectively, in comparison to plants without application, whereas photosynthesis and instantaneous carboxylation efficiency increased by 28.33 and 31.18% via soil and 14.40 and 16.12% via foliar, respectively. The paclobutrazol application, mainly via soil, favored ‘Sol Noturno’ sunflower plants under salt stress, increasing chlorophyll SPAD index and external chapter diameter, and keeping the number of the petals.

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Plants grown under salinity are subject to many morphological and physiological disorders. In this context, practices that can enable the use of saline water are essential. The deleterious effects of salinity can be mitigated by using beneficial microorganisms, especially diazotrophic bacteria. In this context, this study aimed to evaluate the effect of bacterial inoculation and co-inoculation using Bradyrhizobium spp. and Azospirillum brasilense on the growth, nodulation and production of cowpea under salt stress. The experiment was conducted using a randomized block design, in a 4 × 5 factorial arrangement, corresponding to four nitrogen sources (N1 - without nitrogen and without inoculant; N2 - fertilization with mineral nitrogen and without inoculant; N3 - inoculation of Bradyrhizobium spp.; and N4 - co-inoculation of Bradyrhizobium spp. and Azospirillum brasilense) and five values of electrical conductivity of irrigation water - ECw (0.4, 1.9, 3.4, 4.9 and 6.4 dS m-1), with five replicates. Co-inoculation with Azospirillum brasilense and Bradyrhizobium spp. favors the growth, production and nodulation of cowpea plants up to ECw of 0.4 dS m-1. Increase in the electrical conductivity of irrigation water negatively affects the growth, production and nodulation of cowpea plants in Corujinha variety, regardless of the nitrogen source used.

RESUMOO objetivo deste estudo foi avaliar os efeitos de diferentes níveis de salinidade na acumulação de fitomassa de duas cultivares de alface sob cultivo hidropônico. O experimento foi realizado em um ambiente protegido na Universidade Federal de Campina Grande (UFCG), Campus I, durante o período 01 a 22 de setembro de 2016. O delineamento experimental foi inteiramente casualizado (DIC), em esquema fatorial 2x4, duas variedades de alface, Valentina (C1) e Alcione (C2) e quatro níveis de condutividade elétrica da solução nutritiva (CESN) (1,6, 3,6, 5,6 e 7,6 dS m -1 ), totalizando 8 tratamentos com 3 repetições cada, resultando em 24 unidades experimentais. As variáveis analisadas foram o número de folhas, fitomassa fresca e seca de folhas, caule e raízes, e fitomassa total da parte aérea. Observou-se que as variáveis fitomassa fresca das folhas e do caule, e fitomassa seca das folhas foram significativamente afetadas pelos níveis de salinidade, apenas a fitomassa seca das folhas e a fitomassa fresca das raízes diferiram entre as cultivares. O ponto de máxima produção de matéria fresca das folhas foi observado na CESN de 3,5 dS m -1 , o acúmulo de fitomassa decresceu 31,48% para CESN de 7,6 dS m -1 . Houve interação entre os fatores apenas para a massa seca da folha.Palavras-chave: água salina, vegetais, Lactuca sativa L.