Sunflower growth irrigated with sewage effluent under organic fertilization

In the semi-arid region of Brazil due to water scarcity, the use of alternative water sources is of vital importance, such as the use of saline waters and treated sewage effluents. Therefore, in the present work, the growth of sunflower plants irrigated with tap water and treated domestic sewage effluent, associated with organic fertilization was evaluated. The research was carried out in a protected environment at the Federal University of Campina Grande, Campus I, Campina Grande, PB. A completely randomized experimental design with factorial arrangement was used (4 x 2) + 2, with 5 repetitions. the treatments consisted of organic manure dosages (7.5, 10, 12.5 and 15% of manure on a weight basis) and two water sources (supply water and treated domestic sewage effluent). According to the results obtained, it can be indicated that the use of domestic sewage effluent for sunflower irrigation increased sunflower growth in relation to the use of water supply. The application of manure doses of 12.5 and 15% improved the early growth of the sunflower, with significant increases in the growth variables

Germination and osmotic adjustment in Salvia hispanica L. (Lamiaceae) seedlings under water and thermal stress

Salvia hispanica seedlings have stood out for their potentialities in nutrients for agri-food industries. Nevertheless, studies related to this species are still scarce, especially with respect to agronomic factors that enable its propagation and development. Hence, this study aimed to evaluate germination, vigor and osmotic adjustment of S. hispanica seeds and seedlings subjected to water and thermal stress. The experimental design was completely randomized, with treatments arranged in factorial scheme, corresponding to five levels of polyethylene glycol (PEG 6000) (0.0; -0.1; -0.2; -0.3 and -0.4 MPa) and five temperatures (20, 25, 30 and 20-30 °C), with four replicates of 50 seeds in each treatment. Germination test was set on blotter paper, moistened with PEG 6000 solutions at the previously mentioned potentials, under 8-h photoperiod. The following variables were analyzed: germination, germination speed index, seedling shoot length, seedling root length, seedling dry matter and contents of chlorophyll, carotenoids, amino acids, proline and sugars. Polyethylene glycol levels of -0.4 MPa at all temperatures and -0.3 MPa at 30 °C and 20-30 °C enable germination and vigor of S. hispanica seedlings. S. hispanica seedlings are able to perform osmotic adjustment under water stress conditions up to the level of -0.3 MPa, when grown from seeds germinated at temperatures of up to 25 ºC

Pre-germination treatments with plant growth regulators and bioactivators attenuate salt stress in melon: effects on germination and seedling development

The scarcity of surface water has led to the use of underground sources as an alternative for crop irrigation by farmers in semi-arid regions. However, these water sources generally have high salinity, which prevents agricultural production. The objective of this study was to determine the effects of pre-germination treatments with plant growth regulators and bioactivators on melon seeds to attenuate salt stress caused by irrigation water during germination and seedling development. Two trials were carried out separately with the hybrids, Goldex and Grand Prix. The design was completely randomized in a 4 × 3 factorial scheme (four seed treatments and three dilutions of irrigation water). Seeds were treated with salicylic acid and gibberellic acid and the insecticide, thiamethoxam, in addition to the control. Local supply water, artesian well groundwater, and dilution of these waters at a 1:1 ratio were employed for irrigation. Fourteen days after sowing, morphological and physiological analyses were performed, and the material was collected for biochemical determination. The use of saline well water affected the initial development of melon seedlings of the Goldex and Grand Prix hybrids. Pre-germination treatment of Goldex hybrid seeds with gibberellic acid was inefficient at mitigating salt stress. However, the effects of irrigation water salinity on Grand Prix melon seeds pretreated with salicylic acid and thiamethoxam were attenuated

Maturação fisiológica e dormência em sementes de jurema-de-embira (Mimosa ophthalmocentra)

O estudo da maturação fisiológica das sementes é uma importante forma de conhecer o comportamento das espécies vegetais quanto à reprodução, possibilitando assim, conhecer a época ideal de colheita. O estudo de aspectos físicos como tamanho e coloração das sementes, aliado a técnicas de superação de dormência, são estratégias utilizadas para obtenção de sementes com menores níveis de dormência e maior capacidade germinativa. Dessa forma, objetivou-se avaliar os diferentes estádios de maturação fisiológica com base na coloração de frutos e sementes, bem como os seus efeitos sobre a dormência, germinação e vigor de sementes de Mimosa ophthalmocentra. O trabalho foi conduzido no Laboratório de Análise de Sementes do Centro de Ciências Agrárias da Universidade Federal Rural do Semi-Árido.  O delineamento estatístico utilizado foi o inteiramente casualizado, em esquema fatorial 2 × 5 (com e sem quebra de dormência x cinco estádios de maturação), constituindo assim 10 tratamentos em quatro repetições. A máxima qualidade fisiológica e vigor em sementes de Mimosa ophthalmocentra são obtidas em sementes da classe de coloração marrom clara, desde que essas passem por tratamentos pré-germinativos

Germination of spineless Bromelia laciniosa Mart. ex Schult (Bromeliaceae) seeds subjected to chemical scarification

ABSTRACT Bromelia laciniosa, popularly known as ‘macambira’, is a plant found mainly in dry areas of northeast Brazil. This species belongs to the Family Bromeliaceae, whose propagation has been hindered by seed dormancy. This study aimed to evaluate the effectiveness of chemical scarification in the germination of B. laciniosa seeds at two maturation stages, by immersing them in acetone or alcohol for 30, 60 or 90 minutes. Immersing B. laciniosa seeds in acetone (58%) for 90 minutes proved to be an effective method to overcome dormancy. Seeds from mature fruits showed higher germination values.RESUMEN Bromelia laciniosa, conocida popularmente como “macambira”, es una planta encontrada principalmente en áreas secas del Nordeste brasileño. Esta especie pertenece a la familia Bromeliaceae, cuyo fenómeno del adormecimiento en semillas ha dificultado su propagación. En el presente estudio se evaluó la eficiencia de la escarificación química en la germinación de semillas de B. laciniosa, en dos estados de maduración, utilizando acetona y alcohol por 30, 60 y 90 minutos de inmersión de las semillas. La inmersión de las semillas de B. laciniosa en acetona (58%) por 90 minutos se constituye en un eficiente método para la superación del adormecimiento. Las semillas oriundas de frutos maduros proporcionan mayores valores de germinación

Growth and biomass partitioning of mulungu seedlings in response to phosphorus fertilization and mycorrhizal inoculation

The objective of this work was to evaluate the initial growth and biomass partitioning of mulungu <em>(Erythrina velutina</em> Willd.) seedlings under different rates of phosphorus in the presence and absence of arbuscular mycorrhizal fungi (FMA’s). A randomized blocks design in a 5 x 2 factorial arrangement was used, with four replicates and three plants per plot. Treatments consisted of five phosphorus rates (0, 50, 100, 150 and 200 mg.Kg soil<span>^{<span>-1</span>}</span>), using as source the superphosphate fertilizer, and presence or absence of FMA’s. At 98 days after sowing (DAS), shoot height, stem diameter, leaf number, leaf chlorophyll index, leaf dry matter, stem dry matter, root dry matter, leaf area, Dickson quality index and height/stem diameter ratio were evaluated. The phosphorus rate of 200 mg.kg<span>^{<span>-1 </span>}</span>proved to be the most efficient for production of Erythrina velutina seedlings, but with a significant reduction in the biological association of this plant with rhizobacteria. Biomass distribution within the different parts of the plants did not change with distinct rates of P, and there were no benefits in the use of FMA’s until 98 DAS

PRODUÇÃO DE MUDAS DE Enterolobium contortisiliquum E PARTIÇÃO DE ASSIMILADOS EM RESPOSTA À ADUBAÇÃO FOSFATADA E INOCULAÇÃO COM FUNGOS MICORRÍZICOS

This study aimed to evaluate the production of Enterolobium contortisiliquum (Vell.) Morong seedlings and assimilate partitioning under different levels of phosphorus, in the presence and absence of arbuscular mycorrhizal fungi. The experiment was conducted in randomized blocks in a 5x2 factorial design, with four replications represented by three plants each. The first factor consisted of P levels (0, 50, 100, 150 and 200 mg.Kg soil -1 ), using superphosphate fertilizer (P 2 O 5 ) as the phosphorus source. The second factor consisted of the presence or absence of arbuscular mycorrhizal fungi. At 98 days after sowing (DAS), plants were evaluated by non-destructive assessments of shoot height (APA), leaf number (NF) and stem diameter (DC). Then, chlorophyll content index (ICC), leaf dry matter (MSF), stem dry matter (MSC), shoot dry matter (MSPA) and root dry matter (MSR) analyses were conducted. Leaf area (AF), leaf weight ratio (RPF), specific leaf area (AFE), Dickson quality index (IQD) and shoot/root dry matter ratio (MSPA/R) were also determined. The P level of 100 mg.Kg -1 proved to be the most efficient one for the production of Enterolobium contortisiliquum seedlings in Mossoró, Rio Grande do Norte state, with no benefits in the use of mycorrhizal fungi until 98 DAS, promoting photoassimilate distribution between the organs of young seedlings favorable to the establishment in the field