Beneficial Effect of Exogenously Applied Calcium Pyruvate in Alleviating Water Deficit in Sugarcane as Assessed by Chlorophyll a Fluorescence Technique.

The growing demand for food production has led to an increase in agricultural areas, including many with low and irregular rainfall, stressing the importance of studies aimed at mitigating the harmful effects of water stress. From this perspective, the objective of this study was to evaluate calcium pyruvate as an attenuator of water deficit on chlorophyll a fluorescence of five sugarcane genotypes. The experiment was conducted in a plant nursery where three management strategies (E1-full irrigation, E2-water deficit with the application of 30 mM calcium pyruvate, and E3-water deficit without the application of calcium pyruvate) and five sugarcane genotypes (RB863129, RB92579, RB962962, RB021754, and RB041443) were tested, distributed in randomized blocks, in a 3 × 5 factorial design with three replications. There is dissimilarity in the fluorescence parameters and photosynthetic pigments of the RB863129 genotype in relation to those of the RB041443, RB96262, RB021754, and RB92579 genotypes. Foliar application of calcium pyruvate alleviates the effects of water deficit on the fluorescence parameters of chlorophyll a and photosynthetic pigments in sugarcane, without interaction with the genotypes. However, subsequent validation tests will be necessary to test and validate the adoption of this technology under field conditions.

The Effects of Irrigation Water Salinity on the Synthesis of Photosynthetic Pigments, Gas Exchange, and Photochemical Efficiency of Sour Passion Fruit Genotypes.

The objective of this study was to evaluate the synthesis of photosynthetic pigments, gas exchange, and photochemical efficiency of sour passion fruit genotypes irrigated with saline water under the conditions of the semi-arid region of Paraíba state, Brazil. The experiment was conducted at the experimental farm in São Domingos, PB. A randomized block design was adopted, in a 5 × 3 factorial scheme, with five levels of electrical conductivity of irrigation water-ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1)-and three genotypes of sour passion fruit (Gigante Amarelo-'BRS GA1'; Sol do Cerrado-'BRS SC1'; and Catarina-'SCS 437'. The increase in the electrical conductivity of irrigation water negatively affected most of the physiological characteristics of the sour passion fruit at 154 days after transplanting. Significant differences were observed between sour passion fruit genotypes when its tolerance was subjected to the salinity of irrigation water. There was an increase in the percentage of damage to the cell membrane with the increase in the electrical conductivity of irrigation water, with maximum values of 70.63, 60.86, and 80.35% for the genotypes 'BRS GA1', 'BRS SC1', and SCS 437', respectively, when irrigated with water of 3.5 dS m-1. The genotype 'BRS Sol do Cerrado' showed an increase in the synthesis of photosynthetic pigments when irrigated with water of 3.5 dS m-1, with maximum values estimated at 1439.23 µg mL-1 (Chl a); 290.96 µg mL-1 (Chl b); 1730.19 µg mL-1 (Chl t); and 365.84 µg mL-1 (carotenoids). An increase in photosynthetic efficiency parameters (F0, Fm, and Fv) of the genotype 'BRS Gigante Amarelo' was observed when cultivated with water with high electrical conductivity (3.5 dS m-1).

Foliar Applications of Salicylic Acid on Boosting Salt Stress Tolerance in Sour Passion Fruit in Two Cropping Cycles.

Brazil stands out as the largest producer of sour passion fruit; however, the water available for irrigation is mostly saline, which can limit its cultivation. This study was carried out with the objective of evaluating the effects of salicylic acid in the induction of tolerance in sour passion fruit to salt stress. The assay was conducted in a protected environment, using a completely randomized design in a split-plot scheme, with the levels of electrical conductivity of the irrigation water (0.8, 1.6, 2.4, 3.2, and 4.0 dS m-1) considering the plots and concentrations of salicylic acid (0, 1.2, 2.4, and 3.6 mM) the subplots, with three replications. The physiological indices, production components, and postharvest quality of sour passion fruit were negatively affected by the increase in the electrical conductivity of irrigation water, and the effects of salt stress were intensified in the second cycle. In the first cycle, the foliar application of salicylic acid at concentrations between 1.0 and 1.4 mM partially reduced the harmful effects of salt stress on the relative water content of leaves, electrolyte leakage, gas exchange, and synthesis of photosynthetic pigments, in addition to promoting an increase in the yield and quality parameters of sour passion fruit.

Irrigation Strategies with Controlled Water Deficit in Two Production Cycles of Cotton.

Water scarcity is one of the main abiotic factors that limit agricultural production. In this sense, the identification of genotypes tolerant to water deficit associated with irrigation management strategies is extremely important. In this context, the objective of this study was to evaluate the morphology, production, water consumption, and water use efficiency of colored fiber cotton genotypes submitted to irrigation strategies with a water deficit in the phenological phases. Two experiments were conducted in succession. In the first experiment, a randomized block design was used in a 3 × 7 factorial scheme, corresponding to three colored cotton genotypes (BRS Rubi, BRS Jade, and BRS Safira) in seven irrigation management strategies with 40% of the real evapotranspiration (ETr) varying the phenological stages. In the second experiment, the same design was used in a 3 × 10 factorial arrangement (genotypes × irrigation management strategies). The water deficit in the vegetative phase can be used in the first year of cotton cultivation. Among the genotypes, 'BRS Jade' is the most tolerant to water deficit in terms of phytomass accumulation and fiber production.

Effect of Hydrogen Peroxide Application on Salt Stress Mitigation in Bell Pepper (Capsicum annuum L.).

The present study aimed to evaluate the effects of the foliar application of hydrogen peroxide on the attenuation of salt stress on the growth, photochemical efficiency, production and water use efficiency of 'All Big' bell pepper plants. The experiment was conducted under greenhouse conditions in Campina Grande, PB, Brazil. Treatments were distributed in a randomized block design, in a 5 × 5 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water (0.8, 1.2, 2.0, 2.6 and 3.2 dS m-1) and five concentrations of hydrogen peroxide (0, 15, 30, 45 and 60 µM), with three replicates. Foliar application of hydrogen peroxide at concentration of 15 µM attenuated the deleterious effects of salt stress on photochemical efficiency, biomass accumulation and production components of bell pepper plants irrigated using water with an electrical conductivity of up to 3.2 dS m-1. Foliar spraying of hydrogen peroxide at a concentration of 60 µM intensified the effects of salt stress. The 'All Big' bell pepper was classified as moderately sensitive to salt stress, with an irrigation water salinity threshold of 1.43 dS m-1 and a unit decrease of 8.25% above this salinity level.

Salicylic Acid as a Salt Stress Mitigator on Chlorophyll Fluorescence, Photosynthetic Pigments, and Growth of Precocious-Dwarf Cashew in the Post-Grafting Phase.

Salicylic acid is a phytohormone that has been used to mitigate the effects of saline stress on plants. In this context, the objective was to evaluate the effect of salicylic acid as a salt stress attenuator on the physiology and growth of precocious-dwarf cashew plants in the post-grafting phase. The study was carried out in a plant nursery using a randomized block design in a 5 × 4 factorial arrangement corresponding to five electrical conductivity levels of irrigation water (0.4, 1.2, 2.0, 2.8, and 3.6 dS m-1) and four salicylic acid concentrations (0, 1.0, 2.0, and 3.0 mM), with three replications. Irrigation water with electrical conductivity levels above 0.4 dS m-1 negatively affected the relative water content in the leaf blade, photosynthetic pigments, the fluorescence of chlorophyll a, and plant growth and increased electrolyte leakage in the leaf blade of precocious-dwarf cashew plants in the absence of salicylic acid. It was verified through the regression analysis that salicylic acid at a concentration of 1.1 mM attenuated the effects of salt stress on the relative water content and electrolyte leakage in the leaf blade, while the concentration of 1.7 mM increased the synthesis of photosynthetic pigments in precocious-dwarf cashew plants.

Production and Fiber Characteristics of Colored Cotton Cultivares under Salt Stress and H2O2.

Salt stress reduces the yield and quality of colored fiber cotton production, but this problem can be mitigated by the foliar application of hydrogen peroxide in adequate concentrations. In this context, the objective of the present study was to evaluate the production and characteristics of fibers of naturally colored cotton cultivares under irrigation with low- and high-salinity water and leaf application of hydrogen peroxide. The experiment was carried out in a greenhouse under a randomized block design, arranged in 4 × 3 × 2 factorial scheme, corresponding to four concentrations of hydrogen peroxide (0, 25, 50, and 75 µM), three cultivares of colored fiber cotton ('BRS Rubi', 'BRS Topázio', and 'BRS Verde'), and two electrical conductivities of water (0.8 and 5.3 dS m-1), with three replicates and one plant per plot. Irrigation with water of 0.8 dS m-1 associated with a foliar application of 75 µM of hydrogen peroxide favored the lint and seed weight, strength, micronaire index, and maturity of 'BRS Topázio'. The 'BRS Rubi' cotton cultivar showed higher tolerance to salinity, followed by the 'BRS Topázio' and 'BRS Verde' cultivares regarding the yield of seed cotton weight, with reduction below 20% under water of 5.3 dS m-1.

Bacilli Rhizobacteria as Biostimulants of Growth and Production of Sesame Cultivars under Water Deficit.

A strategy using bacilli was adopted aiming to investigate the mitigation of the effects of water deficit in sesame. An experiment was carried out in a greenhouse with 2 sesame cultivars (BRS Seda and BRS Anahí) and 4 inoculants (pant001, ESA 13, ESA 402, and ESA 441). On the 30th day of the cycle, irrigation was suspended for eight days, and the plants were subjected to physiological analysis using an infrared gas analyzer (IRGA). On the 8th day of water suspension, leaves were collected for analysis: superoxide dismutase, catalase, ascorbate peroxidase, proline, nitrogen, chlorophyll, and carotenoids. At the end of the crop cycle, data on biomass and vegetative growth characteristics were collected. Data were submitted for variance analysis and comparison of means by the Tukey and Shapiro-Wilk tests. A positive effect of inoculants was observed for all characteristics evaluated, contributing to improvements in plant physiology, induction of biochemical responses, vegetative development, and productivity. ESA 13 established better interaction with the BRS Anahí cultivar and ESA 402 with BRS Seda, with an increase of 49% and 34%, respectively, for the mass of one thousand seeds. Thus, biological indicators are identified regarding the potential of inoculants for application in sesame cultivation.

Photosynthetic Responses, Growth, Production, and Tolerance of Traditional Varieties of Cowpea under Salt Stress.

Cowpea is the main subsistence crop-protein source-for the Brazilian semi-arid region. The use of salt-stress-tolerant varieties can improve crop yields. We evaluated the effect of irrigation with brackish water on the growth, photosynthetic responses, production, and tolerance of fifteen traditional varieties of cowpea. The experiment was conducted in randomized blocks, in a 15 × 2 factorial scheme, composed of 15 traditional varieties of cowpea and two salinity levels of irrigation water (0.5 and 4.5 dS m-1), with five replicates. Plants were grown in pots containing 10 dm3 of soil for 80 days. The reduction in the photosynthetic rate of cowpea varieties occurs mainly due to the decrease in stomatal conductance caused by salt stress. Salt stress increased the electron transport rate and photochemical quenching of cowpea varieties, but stress-tolerant varieties increased the CO2 assimilation rate and instantaneous carboxylation efficiency. The Ceará, Costela de Vaca, Pingo de Ouro, Ovo de Peru, and Sempre Verde varieties are tolerant to salt stress. Salt stress decreases 26% of the production of tolerant varieties to salt stress and 54% of susceptible varieties. The present findings show the existence of variability for saline stress tolerance in traditional varieties of cowpea and that Ceará, Costela de Vaca, Pingo de Ouro, and Ovo de Peru varieties are more suitable for crops irrigated with saline water.

Physiological responses and production of mini-watermelon irrigated with reject brine in hydroponic cultivation with substrates.

The scarce availability of good quality water for irrigation in semi-arid regions leads to the reuse of waters, such as reject brine. Associated with this, the use of alternatives, such as hydroponic cultivation in substrates suitable for the development of profitable crops, such as watermelon, a species considered moderately sensitive to salinity, will allow new opportunities for communities assisted by desalination plants. An experiment was conducted in a plastic greenhouse to evaluate the growth, physiological responses, yield, and fruit quality of 'Sugar Baby' mini-watermelon cultivated in a hydroponic system with reject brine from desalination plants and different substrates. The experimental design was randomized blocks, with treatments arranged in a 5 × 4 factorial scheme, corresponding to five mixtures of reject brine (9.50 dS m-1) and tap water (0.54 dS m-1) applied to mini-watermelon plants, in an open hydroponic system, with four types of substrate and four replicates, with two plants per plot. Mini-watermelon plants grown in coconut fiber substrate showed the best growth and production. On the other hand, washed sand was the substrate that most hampered the development of plants in all mixtures. The use of reject brine to prepare the nutrient solution reduced the growth and production of mini-watermelon, mainly in mixtures with salinity above 4.00 dS m-1. The changes in gas exchange caused by salt stress in mini-watermelon were of stomatal nature. Mini-watermelon has high energy stability under conditions of salt stress.

Growth and fluorescence of 'Tahiti' acid lime/rootstock on Sunki mandarin hybrids under salinity / Crescimento e fluorescência de limeira ácida 'Tahiti' enxertada em híbridos de tangerineira sunki sob sal inidade

The objective of this study was to evaluate the ecophysiological behavior of 'Tahiti' acid lime/rootstock grafted on Sunki mandarin hybrids during the prefloration stage of the plants, in the field, under saline stress. The progenies originating from crossings of the 'Sunki' mandarin with 'Rangpur' lime and Poncirus trioliata, as rootstocks, combined with the 'Tahiti' acid lime as a scion. The experiment was carried out under field conditions, at the Federal University of Campina Grande (UFCG), Pombal PB fields. In drainage lysimeter of 150 dm3, studying 10 scion/rootstock combinations, irrigated with two water salinity levels (CEa) (S1 = 0.3 and S2 = 3.0 dS m-1) making a 10 x 2 factorial scheme. The experimental design was a randomized block design, with 3 replicates and each plot consisting of a useful plant, totalizing 60 parcels. The scion/rootstock plants were transplanted at one year of age from the rootstocks sowing, being the beginning of the applications of the saline stress to the 15 days after the transplant lasting until the period of flowering, that is, up to 195 days after transplanting, During this period the plants were analyzed for growth and chlorophyll fluorescence a. The combinations less sensitive to salinity were composed of the 'Tahiti' grafted with TSKFL x (LCR x TR) - 018, TSKFL x TRBK - 011 and TSKFL x TRBK - 030, it being possible to use saline water with up to 3.0 dS m-1 in irrigation. Salinity did not damage the biochemical phase of the scion/rootstock combinations, only affecting the initial fluorescence of the lighted tissue.

Objetivou-se estudar o crescimento e a fluorescência da clorofila a em limeira ácida 'Tahiti' enxertada em híbridos de tangerineira 'Sunki' sob salinidade da água durante a fase de préfloração das plantas. Assim, com base em um delineamento experimental de blocos ao acaso, foram avaliadas dez combinações copa/porta-enxerto, referentes à referida limeira ácida em combinação com dez porta-enxertos (nove híbridos e o limoeiro 'Cravo Santa Cruz' como testemunha), irrigadas com dois níveis de salinidade da água (CEa) (S1=0,3 e S2=3,0 dS m-1), perfazendo um esquema fatorial 10 x 2, que foi repetido em três blocos e com parcela constituída por uma planta útil, totalizando 60 parcelas. As mudas enxertadas foram transplantadas aos 365 dias após a semeadura dos porta-enxertos, em lisímetros de 150 dm3, que foram preenchidos com um Neossolo Flúvico da região, sendo o início das aplicações do estresse salino aos 15 dias após o transplante (DAT), perdurando até o período de floração, ou seja, até os 195 DAT, avaliando o crescimento e a fluorescência da clorofila a. As combinações com maior crescimento quando irrigadas com água de condutividade de 0,3dS-1 foram aquelas com os porta-enxertos TSKC x (LCR x TR) ­ 017, TSKC x (LCR x TR) ­ 012, TSKFL x (LCR x TR) ­ 018, TSKFL x TRBK ­ 011 e TSKFL x TRBK ­ 028. A salinidade não ocasionou dano à fase bioquímica das combinações copa/porta-enxerto, apenas afetado a fluorescência inicial do tecido iluminado. É possível usar água salina de até 3,0 -1 no cultivo de citros, caso se empreguem combinações menos sensíveis, como aquelas tendo como porta-enxertos os híbridos TSKC x (LCR x TR) ­ 017, TSKFL x (LCR x TR) ­ 018, TSKFL x TRBK ­ 011 e TSKFL x TRBK ­ 030.

Growth and physiology of annona squamosa l. under different irrigation depths and phosphate fertilization / Crescimento e fisiologia de mudas de Annona squamosa L. sob diferentes lâminas de irrigação e adubação fosfatada

This study aimed to evaluate the growth and physiology of Annona squamosa seedlings under increasing irrigation depths and phosphorus doses. The experiment was conducted in protected environment, evaluating five irrigation depths and four P2O5- doses, arranged in 5 x 4 factorial scheme, in randomized blocks, with four replicates and one plant per plot. Treatments were irrigation depths of 60, 80, 100, 120 and 140% of the real evapotranspiration of the seedlings ­ ETr and phosphorus doses of 0, 350, 700 and 1050 mg dm-3 of P2O5-. Plants were evaluated at 120 days after transplanting with respect to growth, gas exchanges, leaf water potential and total dry matter accumulation. Phosphorus dose of 350 mg dm-3 promotes satisfactory dry matter accumulation for A. squamosa seedlings, especially under 100% ETr irrigation. Leaf water potential and gas exchanges of A. squamosa are affected by water stress, through both lack and excess of water. Stomatal conductance is the variable most sensitive to the lack of water, whereas photosynthesis and water use efficiency are the most sensitive to the excess of water. Irrigation depth of 100% ETr is ideal to produce A. squamosa seedlings, but the irrigation depth of 80% ETr can be used to produce these seedlings, disregarding small losses of growth

Objetivou-se avaliar o crescimento e a fisiologia de mudas de A. squamosa sob lâminas crescentes de irrigação e doses de fósforo. O experimento foi conduzido em ambiente protegido, avaliando cinco lâminas de irrigação e quatro doses P2O5, arranjados em esquema fatorial 5 x 4, em blocos casualizados, com quatro repetições e uma planta por parcela. Os tratamentos das lâminas foram 60, 80, 100, 120 e 140% da evapotranspiração real das mudas ­ ETr e as quatro doses de fósforo 0, 350, 700 e 1050 mg dm-3 de P2O5. As plantas foram avaliadas aos 120 dias após o transplantio, quanto ao crescimento, trocas gasosas, potencial hídrico foliar e acúmulo de matéria seca total. A dose de fósforo de 350 mg dm-3 proporciona acúmulo de matéria seca satisfatório para as mudas de A. squamosa, principalmente sob irrigação com 100% da ETr. O potencial hídrico foliar e as trocas gasosas da A. squamosa são afetadas pelo estresse hídrico, tanto por falta como por excesso de água, sendo a condutância estomática a variável mais sensível a falta de água e a fotossíntese e eficiência do uso da água as mais sensíveis ao excesso de água. A lâmina de 100% da ETr é a ideal para a produção de mudas de A. squamosa, porém a lamina de 80% da ETr pode ser utilizada para a produção de mudas de A. squamosa, admitindo-se pequenas perdas no crescimento.

Ecophysiology of west indian cherry irrigated with saline water under phosphorus and nitrogen doses / Ecofisiologia da aceroleira irrigada com água salin a sob doses de fósforo e nitrogênio

The quantitative and qualitative scarcity of water resources is a frequent problem in the semi-arid region of the Brazilian Northeast. The availability of water for irrigation with high content of dissolved salts is common, affecting the growth and development of the crops. Thus, it is necessary to adopt strategies that allow the establishment of irrigated agriculture in this region. The objective of this study was to evaluate the effect of water salinity and phosphorus/nitrogen combinations on the ecophysiology of the West Indian cherry grafted in the first year of cultivation. The research was carried out in a protected environment, in lysimeters filled with a Regolithic Neosol of loamy clay texture, having low initial phosphorus content. The experiment was arranged in a randomized block design, arranged in a 5x4 factorial scheme, with five levels of electrical conductivity of the irrigation water - ECw (0.6, 1.4, 2.2, 3.0 and 3.8 dS m -1) and four managements of fertilization with phosphorus and nitrogen (100:100; 140:100; 100:140 and 140:140% P/N of the recommendation), with three replications, each plot consisting of one plant. Increased salinity of irrigation water reduced growth, photosynthesis and the production of West Indian cherry. Fertilization with 140% of recommendation of the phosphorus and nitrogen minimizes the deleterious effect of salinity on West Indian cherry irrigated with water up to 3.0 dS m-1.

A escassez quantitativa e qualitativa dos recursos hídricos é um problema frequente na região semiárida do Nordeste brasileiro, sendo comum a disponibilidade de água para irrigação com elevados teores de sais, afetando o crescimento e o desenvolvimento das culturas. Assim é necessário adoção de estratégias que viabilize o estabelecimento de cultivo irrigado nessa região.Com isso,objetivou-se com este trabalho avaliar o efeito da salinidade de água e manejos da combinação fósforo/nitrogênio sobre a ecofisiologia da acerola enxertada no primeiro ano de cultivo. A pesquisa foi realizada em ambiente protegido, em lisímetros preenchidos com Neossolo Regolítico de textura franco-argilosa, possuindo baixo teor inicial de fósforo. O experimento foi instalado em delineamento de blocos casualizados, arranjados em esquema fatorial 5x4, sendo cinco níveis de condutividade elétrica da água de irrigação - CEa (0,6; 1,4; 2,2; 3,0 e 3,8 dS m-1) e quatro manejos de adubação com fósforo e nitrogênio (100:100; 140:100; 100:140 e 140:140% da recomendação de P/N), com três repetições, sendo cada parcela constituída de uma planta. O aumento da salinidade da água de irrigação reduziu o crescimento, a fotossíntese e a produção da aceroleira. Adubação com 140% da recomendação de fósforo e nitrogênio minimiza o efeito deletério da salinidade sobre a produção de aceroleira irrigada com água de até 3,0 dS m-1.

Growth and physiology of citrus rootstocks under salt stress / Crescimento e fisiologia de porta-enxertos de citros sob estresse salino

In order to study the growth and physiology of citrus rootstocks under saline water irrigation, during formation of rootstocks, an assay was carried out in a factorial scheme, 2 x 6, corresponding to two levels of salinity of the nutrient solution: 0.3 and 4.0 dS m-1 and six genotypes provided by the Citrus Breeding Program of Embrapa Cassava & Fruits-CBP, distributed in randomized block design with three replications. The genotypes were: 1.'Santa Cruz Rangpur' lime (SCRL) (Citrus limonia Osbeck), 2. 'Florida Rough' lemon (FRL) (Citrus jambhiri Lush.), 3. 'Volkamer' lemon (VKL) (C. volkameriana V. Ten. &Pasq.), 4. CSM x SWC- 028, 5. CSM x SWC- 033 and 6.CSM x SWC-041, the last three hybrids of common 'Sunki' mandarin (CSM) [C.sunki (Hayata) hort. ex Tanaka] with 'Swingle' citrumelo (SWC) [C. paradisi Macfad. x Poncirus trifoliata (L.) Raf.]. Nucellar plants from these genotypes were grown in alternative hydroponic system, using Leonard jars. Application of nutrient solution made with saline water started from 90 days after sowing until 120 days, when the growth and physiology parameters of plants were evaluated. Salt stress influenced the growth and physiological parameters in all genotypes. Salt stress did not influence the chlorophyll a fluorescence in the genotypes VKL and CSM x SWC- 041, indicating no damage to the photosynthetic apparatus. The CSM x SWC- 041, 'Santa Cruz Rangpur' lime, 'Florida Rough' lemon and 'Volkamer' lemon are the more tolerant genotypes to salinity based on growth rate.

A fim de estudar o crescimento e a fisiologia de porta-enxertos de citros sob irrigação com água salina, durante a formação de porta-enxertos, realizou-se um ensaio fatorial 2 x 6, correspondente a dois níveis de salinidade da solução nutritiva: 0,3 e 4,0 dS m-1 e seis genótipos fornecidos pelo Programa de Melhoramento de Citros da Embrapa Mandioca & Fruticultura-PMGC, distribuídos em delineamento em blocos casualizados com três repetições. Os genótipos foram: 1. 'limoeiro Cravo Santa Cruz' (LCRSTC) (Citrus limonia Osbeck), 2. 'limoeiro Rugoso da Flórida' (LRF) (Citrus jambhiri Lush.), 3. 'limoeiro Volkameriano' (LVK) (C. Volkameriana V. Ten. & Pasq.), 4. CSM x SWC- 028, 5. CSM x SWC- 033 e 6. CSM x SWC-041, os últimos três híbridos de tangerineira 'Sunki' comum (CSM) [C. sunki (Hayata) hort. Ex Tanaka] com citrumelo 'Swingle' (SWC) [C. Paradisi Macfad. x Poncirus trifoliata (L.) Raf.] Plantas de origem nucelar desses genótipos foram cultivadas em sistema hidropônico alternativo, utilizando vasos Leonard. A aplicação de solução nutritiva feita com água salina iniciou-se a partir de 90 dias após a semeadura até 120 dias, quando foram avaliados os parâmetros de crescimento e fisiologia das plantas. O estresse salino influenciou o crescimento e os parâmetros fisiológicos em todos os genótipos. O estresse salino não influenciou a fluorescência da clorofila a nos genótipos VKL e CSM x SWC-041, indicando não haver danos ao aparelho fotossintético. O CSM x SWC-041, 'limoeiro Cravo Santa Cruz', 'limoeiro Rugoso da Flórida' e 'limoeiro Volkameriano' são os genótipos mais tolerantes à salinidade com base na taxa de crescimento.

Saline stress onto growth and physiology of trifoliate citrus hybrids during rootstock formation / Estresse salino no crescimento e fisiologia de híbridos trifoliados de citros enquanto porta-enxertos

High salts concentrations in soil and water are common in semi-arid regions, which reduces the growth and development of crops, especially sensitive plants, such as citrus, being important to identify tolerant materials as well as to study the physiology of these plants. An experiment was conducted evaluate the growth and physiology of citrus trifoliate citrus hybris during their early stage of development (seedling stage) under salt stress conditions. These hydrids were obtained through the Citrus Breeding Program of Embrapa Cassava & Fruits consisting of 'Common sunki' mandarin x 'Argentina' citrange - 019, 'Common sunki' mandarin x ('Rangpur' lime x Poncirus trifoliata) - 040, Trifoliate hybrids - 069, 116 and 127, distributed in a randomized block design with three replications. Nucellar seedlings of the genotypes were grown in an hydroponic system using Leonard jars. The application of nutrient solution with saline water started 90 days after sowing, extending to 120 days, when the seedlings were evaluated for plant growth and physiology. The genotypes common 'Sunki' mandarin x 'Argentina' citrange - 019, Common 'Sunki' mandarin x ('Rangpur' lime x P. trifoliata) - 040 and Trifoliate hybrid - 069 showed the greater tolerance to salinity, while the Trifoliate hybrid - 116 and 127 were found to be the less tolerant.

Altas concentrações de sais no solo e na água são comuns em regiões semiáridas, o que reduz o crescimento e o desenvolvimento das culturas, notadamente as sensíveis, como os citros, sendo importante a identificação de materiais tolerantes assim como o estudo da fisiologia destes. Assim, realizou-se um experimento para avaliar o crescimento e a fisiologia de híbridos de Poncirus trifoliata durante a formação de porta-enxertos sob condições de estresse salino. O experimento foi realizado usando um esquema factorial, 2 x 5, correspondendo a dois níveis de salinidade na solução nutritiva (2,6 e 6,3 dS m-1) e cinco híbridos de citros. Tais híbridos foram obtidos a partir do programa de melhoramento genético de citros da Embrapa Mandioca e Fruticultura, PMG ­ Citrus, a saber: tangerineira 'Sunki Comum' x citrange 'Argentina' ­ 019; tangerineira 'Sunki Comum' x (limoeiro 'Cravo' x Poncirus trifoliata) ­ 040 e os híbrido trifoliados ­ 069, 116 e 127. Os tratamentos foram distribuídos em delineamento experimental de blocos ao acaso, com três repetições. As plantas de origem nucelar dos genótipos foram cultivadas em sistema hidropônico por meio de vasos de Leonard. A aplicação das soluções nutritivas com águas salinas começaram aos 90 dias após a semeadura, se extendendo até os 120 dias, quando as plantas foram avaliadas em relação ao crescimento e a fisiologia. Os genótipos tangerineira 'Sunki Comum' x citrange 'Argentina' - -19, tangerineira Sunki Comum x x (limoeiro 'Cravo' x Poncirus trifoliata) ­ 040 e o híbrido trifoliado ­ 069 tiveram maior tolerância à salinidade, enquanto os híbridos trifoliados 116 e 127 foram os menos tolerantes.

Phytochemical study of Pilosocereus pachycladus and antibiotic-resistance modifying activity of syringaldehyde

ABSTRACT Pilosocereus pachycladus F. Ritter, Cactaceae, popularly known as "facheiro", is used as food and traditional medicine in Brazilian caatinga ecoregion. The plant is used to treat prostate inflammation and urinary infection. The present work reports the first secondary metabolites isolated from P. pachycladus. Therefore, the isolated compound 4-hydroxy-3,5-dimethoxy benzaldehyde (syringaldehyde) was evaluated as modulator of Staphylococcus aureus pump efflux-mediated antibiotic resistance. The isolation of compounds was performed using chromatographic techniques and the structural elucidation was carried out by spectroscopic methods. In order to evaluate syringaldehyde ability to modulate S. aureus antibiotic resistance, its minimum inhibitory concentrations (µg/ml) was first determinate, then, the tested antibiotics minimum inhibitory concentrations were determined in the presence of the syringaldehyde in a sub-inhibitory concentration. The chromatographic procedures led to isolation of twelve compounds from P. pachycladus including fatty acids, steroids, chlorophyll derivatives, phenolics and a lignan. The syringaldehyde did not show any antibacterial activity at 256 µg/ml against S. aureus. On the other hand the compound was able to reduce the antibiotic concentration (tetracycline, norfloxacin, ethidium bromide) required to inhibit the growth of drug-resistant bacteria, showing the ability of syringaldehyde of inhibiting the efflux pump on these bacteria.

New Alcamide and Anti-oxidant Activity of Pilosocereus gounellei A. Weber ex K. Schum. Bly. ex Rowl. (Cactaceae).

The Cactaceae family is composed by 124 genera and about 1438 species. Pilosocereus gounellei, popularly known in Brazil as xique-xique, is used in folk medicine to treat prostate inflammation, gastrointestinal and urinary diseases. The pioneering phytochemical study of P. gounellei was performed using column chromatography and HPLC, resulting in the isolation of 10 substances: pinostrobin (1), ß-sitosterol (2), a mixture of sitosterol 3-O-ß-d-glucopyranoside/stigmasterol 3-O-ß-d-glucopyranoside (3a/3b), 13²-hydroxyphaeophytin a (4), phaeophytin a (5), a mixture of ß-sitosterol and stigmasterol (6a/6b), kaempferol (7), quercetin (8), 7'-ethoxy-trans-feruloyltyramine (mariannein, 9) and trans-feruloyl tyramine (10). Compound 9 is reported for the first time in the literature. The structural characterization of the compounds was performed by analyses of 1-D and 2-D NMR data. In addition, a phenolic and flavonol total content assay was carried out, and the anti-oxidant potential of P. gounellei was demonstrated.

Gas exchange and fruit yield of yellow passionfruit genotypes irrigated with different rates of ETo replacement / Trocas gasosas e produção de frutos de genótipos de maracujazeiro-amarelo irrigados com diferentes taxas de reposição da ETo

Water is a limiting factor in agricultural activity and its deficiency in the soil affects the physiological processes of the plant and later interferes in the production of the culture. Aiming to evaluate the influence of different rates of reference evapotranspiration (ETo) replacement, over the leaf gas exchange and yield of hybrid yellow passionfruit plants, this experiment was carried out from August/2009 to September/2010, in an area of the semiarid region of the state of Paraiba, Brazil. The treatments consisted of the combination of four levels of irrigation (33, 66, 100 and 133% of ETo replacement) and two hybrid yellow passion fruit species ('BRS Sol do Cerrado' and 'BRS Gigante Amarelo'), in an experimental randomized block design, with five replications. The following variables were evaluated: gas exchange ­ stomatal conductance (gs), transpiration (T), net photosynthesis (A), instantaneous water use efficiency (IWUE), internal carbon concentration (Ci) and instantaneous carboxylation efficiency (A/Ci); fruit weight (distributed into three classes: 'A', 'B' and 'C', per plant) and also, the total production per plant. The gas exchange rates were higher in the 'BRS Sol do Cerrado' hybrid, in which a higher production was registered when irrigated with 133% of the ETo. The 'BRS Gigante Amarelo' genotype is most indicated to grow under low water availability.

A água é um fator limitante à atividade agrícola e sua deficiência no solo afeta os processos fisiológicos da planta, interferindo, posteriormente, na produção da cultura. Com esse enfoque, foi conduzido este experimento em área do semiárido paraibano, no período de agosto/2009 a setembro de 2010, objetivando-se avaliar a influência de diferentes taxas de reposição da ETo, sobre trocas gasosas e rendimento de híbridos de maracujazeiroamarelo. Os tratamentos consistiram da combinação entre quatro lâminas de irrigação (33, 66, 100 e 133% de reposição da ETo) e dois híbridos de maracujazeiro-amarelo ('BRS Sol do Cerrado' e 'BRS Gigante Amarelo'), no delineamento experimental em blocos casualizados, com cinco repetições. Foram avaliados: trocas gasosas - condutância estomática (gs), transpiração (T), taxa de fotossíntese líquida (A), eficiência do uso da água (A/T), concentração de carbono interna (Ci) e eficiência instantânea de carboxilação (A/Ci); peso de frutos (distribuídos em três classes 'A', 'B' e 'C', por planta) e, também, a produção total por planta. As taxas de trocas gasosas foram maiores no híbrido 'BRS Sol do Cerrado', em que se registrou a maior produção, quando irrigado com 133% da ETo. O genótipo 'BRS Gigante Amarelo' é mais indicado para cultivo sob baixa disponibilidade hídrica.

Desenvolvimento e produção de ecótipos de feijoeiro cultivados na época das águas sob irrigação suplementar / Development and production of common bean ecotypes grown in the rainy season under supplementary irrigation

O cultivo do feijoeiro, Phaseolus vulgaris L., possui grande importância para o Brasil, sobretudo no âmbito econômico e social. Assim, a utilização de ecótipos de feijoeiro promissores associada à otimização dos recursos hídricos configura importante estratégia para a agricultura sustentável em regiões semiáridas. Objetivou-se com este trabalho avaliar o comportamento de ecótipos de feijoeiro cultivados na época das águas com irrigação suplementar. O experimento foi no campus Experimental de Ecofisiologia Vegetal da Universidade Estadual da Paraíba, situada na microrregião de Catolé do Rocha, PB. Utilizou-se o delineamento experimental em blocos casualizados em fatorial 3x4, sendo três ecótipos de feijoeiro (Eco1= G2227, Eco2= BRA 130583 CIAT G6490 e Eco3= BAT 477) e quatro lâminas de irrigação suplementar com 50; 75; 100 e 125% da evapotranspiração de referência (ETo), em três repetições. As variáveis analisadas foram: percentagem e índice de velocidade de emergência, comprimento da haste principal, taxa de crescimento relativo, número de vagens por planta, número de grãos por vagem, massa de 100 grãos, fitomassa da parte aérea e eficiência fotossintética. Os ecótipos de feijoeiro analisados divergem entre si quanto aos aspectos de germinação, crescimento, componentes da produção (NGV e FMA) e eficiência fotossintética. O ecótipo 1 apresenta melhor desempenho quanto aos componentes da produção observados nas condições de Semiárido.

The cultivation of common bean Phaseolus vulgaris L. has great importance for Brazil, especially in the economic and social sector. Thus, the use of promising bean ecotypes associated with optimization of water resources sets an important strategy for sustainable agriculture in semiarid regions. This study was developed in order to evaluate the behavior of common bean ecotypes grown in the rainy season with supplementary irrigation. The experiment was carried out at campus Experimental Plant Ecophysiology at the State University of Paraiba, located in the microregion of Catolé do Rocha - PB. A randomized block experimental design in factorial 3x4 was used, with three common bean ecotypes (Eco1 = G2227, Eco2 BRA = 130583 CIAT G6490 and Eco3 BAT = 477) and four levels of supplementary irrigation (50, 75, 100 and 125% of reference evapotranspiration, ETo) in three replications. The variables analyzed were: percentage and emergence speed index, main branch length, growth rate relative crop, number of pods per plant, number of grains per pod, weight of 100 grains, shoots dry matter and photosynthetic efficiency. The bean ecotypes analyzed were different in aspects of germination, growth, yield components (NVG e FMA) and photosynthetic efficiency. The ecotype 1 shows better performance on the yield components observed in the semiarid conditions.

Aspectos técnicos e econômicos da bananeira 'Prata-Anã' sob fertirrigação nos tabuleiros costeiros de Sergipe / Technical and economical aspects of the banana tree "Prata-Anã" under fertirrigation in the coastal tablelands of Sergipe

Neste trabalho, objetivou-se estudar os efeitos de doses de nitrogênio e potássio via água de irrigação, sobre o tempo de colheita, componentes da produção: número de pencas, número de frutos pencas-1, número de frutos cacho-1 e massa do cacho planta-1, e lucratividade da bananeira Prata-Anã em tabuleiros costeiros do Estado de Sergipe. O experimento foi conduzido no campo, utilizando um arranjo fatorial 4x4 com quatro blocos casualizados, na Estação Experimental da Universidade Federal de Sergipe. Foram testados dois fatores: nitrogênio (0; 350; 700 e 1050, em kg ha-1 de N, na forma de uréia) e potássio (0; 400; 800 e 1200, em kg ha-1 de K2O, na forma de cloreto de potássio). O primeiro ciclo da bananeira 'Prata-Anã' é prolongado em situações de deficiências de N e K. O maior rendimento do cacho (32,56t ha-1) é obtido com a aplicação de 1050kg ha-1 ano-1 de N e 1112kg ha-1 ano-1 de K2O, cujas doses proporcionam uma lucratividade de 27,75 por cento e uma redução do custo de produção de 40,54 por cento.

The objective of the work was to study the effects of doses of N and K applied through irrigation water, on the number of days between planting and harvesting, yield components (number of hands, number of fruits per hands, number of fruits per bunch, bunch weight per plant) and the profitability of the 'Prata-Anã' banana, in the coastal tablelands of Sergipe State. The experiment was carried out in the field at the Sergipe Federal University Experimental Station. A 4² factorial in a randomized block experimental design was used. Treatments were nitrogen (0; 350; 700 e 1050, kg ha-1 of N, as urea) and potassium (0; 400; 800 e 1200, kg ha-1 of K2O, as potassium chloride). Nitrogen and potassium deficiencies increased the number of days between planting and harvesting in the first cycle. Maximum yield of 32.56 t ha-1 was associated with 1050 kg ha-1 year-1 of N and 1112kg ha-1 year -1 of K2O. These doses were able to increase net income by 27.75 percent and reduced costs by 40.54 percent.