Morphophysiology of the passion fruit ‘BRS Rubi do Cerrado’ irrigated with saline waters and nitrogen fertilization

This study aimed to evaluate the gas exchanges and growth of the purple passion fruit cultivar ‘BRS Rubi do Cerrado’ as a function of the salinity levels of the irrigation water and nitrogen fertilization. The research was conducted in pots adapted as drainage lysimeters, placed within a plant nursery, using a Regolithic Neosol of sandy texture, in the municipality of Pombal-PB, Brazil. A randomized block design was used, testing five levels of electrical conductivity of irrigation water (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1) associated with four doses of nitrogen (50, 75, 100, and 125% of the recommendation). The irrigation water salinity above 0.3 dS m-1 compromised the leaf area and the relative water content of the purple passion fruit ‘BRS Rubi do Cerrado’. High doses of nitrogen enhance the deleterious effects of irrigation water salinity on stomatal conductance, transpiration, internal CO2 concentration, CO2 assimilation rate, number of leaves, stem diameter, and height of purple passion fruit plants. When waters with salinity levels of up to 1.3 dS m-1 are used, the dose of 125 mg of N kg-1 of soil is recommendation for providing increases in the CO2 assimilation rate of the purple passion fruit ‘BRS Rubi do Cerrado’ at 70 days after sowing (DAS). Water salinity increases electrolyte leakage, regardless of nitrogen doses.

Ornamental potential of species from the ferruginous Campo rupestre of the Carajás National Forest, Brazilian Amazon

The flora of the ferruginous Campo rupestre that occur over the immense iron deposits of the Carajás National Forest is very unique, with several endemic and rare species. This vegetation is directly affected by mining activity, as a result of vegetation suppression and the profound disfigurement of habitats. The objective of this work was to identify the ornamental potential of the flora of the ferruginous Campo rupestre, as a strategy for ex situ conservation of ecosystem species. The species present in ten plots of 5 x 5 m were surveyed in different areas of the ferruginous Campo rupestre on the N1 plateau and the ornamental potential of each species was evaluated following a characterization key, considering morphology and habitat of occurrence. Subsequently, the species were compared with those already present on the market, as ornamental, based on the literature and on sites specialized in the sale of ornamental plants in Brazil. A total of 33 species with ornamental potential were found, distributed in 32 genera and 19 families. Most species showed high functionality for ornamentation and similarity with nationally consolidated ornamentals. Catasetum planiceps, Cyrtopodium andersonii, Epidendrum nocturnum, Mandevilla scabra, Norantea guianensis and Sobralia liliastrum have a consolidated ornamental market. The data collected support ex situ conservation strategies of the flora of the ferruginous Campo rupestre, such as its valorization, local commercialization and income generation for small extractivists in the region.

Métodos de aplicação de peróxido de hidrogênio em mudas de gravioleira irrigadas com água salina

A aclimatação das plantas ao estresse salino, por meio de aplicação de peróxido de hidrogênio, ocorre devido à ativação do sistema de defesa antioxidante. Neste sentido, objetivou-se com o estudo avaliar os teores de pigmentos fotossintéticos e a eficiência fotoquímica de mudas de gravioleira sob irrigação com águas salinas e distintos métodos de aplicação de peróxido de hidrogênio. O estudo foi realizado em condições de casa de vegetação, em esquema 5 x 4, sendo cinco níveis de condutividade elétrica da água de irrigação – CEa (0,6; 1,2; 1,8; 2,4 e 3,0 dS m-1) e quatro métodos de aplicação de peróxido de hidrogênio- MA (sem aplicação de H2O2, aplicação via embebição das sementes, aplicação via pulverização foliar e aplicação via embebição das sementes e pulverização foliar). A salinidade da água de irrigação até 1,4 e 1,1 dS m-1provocou aumento na síntese de clorofila b e carotenoides, respectivamente. Já a irrigação com água a partir de 0,6 dS m-1 reduziu a síntese de clorofila a e total das plantas de gravioleira. A aplicação de 20 μm de H2O2via embebição da semente resulta em aumento nos teores de clorofila a e b, total, fluorescência máxima e variável das mudas de gravioleira.A embebição das sementes com peróxido de hidrogênio aumentou a fluorescência inicial da clorofila nas plantas irrigadas com água de 1,2 dS m-1.

Concentrations of indolebutyric acid on air-layering of guava cv. Paluma

Nowadays, the predominant technique for the commercial propagation of guava seedlings is through cuttings, using herbaceous cuttings that need a specialized infrastructure with intermittent misting, clean water, exhausters, water filters, and fans. As an alternative to plant propagation by cuttings, this study aimed to evaluate the influence of concentrations of indolebutyric acid (IBA) on the rooting of branches of the guava cv. Paluma by air-layering. The experimental design was in randomized blocks, with four replications and 10 air layers per plot. The treatments consisted of six concentrations of IBA powder mixed with industrial talcum: 0, 1,000, 2,000, 3,000, 4,000, and 5,000 mg.kg-1. Four adult guava parents that were in the off-season period were used. For the preparation of the air layers, the stems were girdled with a 4.0 cm width, using a steel blade, by removing the bark until exposing the cambium region, followed by IBA application and wrapping of the branches with a plastic bag containing moist organic substrate. The following variables were evaluated 120 days after air-layering: percentage of rooted and callused air layers, longest root length, and root dry matter. The analysis of variance indicated no significant differences between the IBA concentrations for all variables, but the rooting percentages were high (68.6 to 92.2%) regardless of the application of the exogenous auxin.

Growth and nutritional diagnosis of Rosemary plants submitted to nitrogen and sulfate fertilization

Studies on the cultivation of medicinal plants are of relevance to the population since they are primary sources of medication. Among these plants stands out the rosemary (Rosmarinus officinalis L.) for having diverse therapeutic properties. The objective of this work was to evaluate the initial growth and nutritional status of rosemary plants grown with different co’ncentrations of nitrogen and sulfur. The treatments were distributed in a 4x2 factorial scheme with four nitrogen doses: 105, 210, 315, and 420 mg L-1 of nitrogen combined with two sulfur doses: 32 and 64 mg L-1 with seven replications totaling 56 experimental units. The seedlings were obtained through asexual propagation (cuttings), originating from parent plants. The experimental units were arranged in a completely randomized design. Growth evaluations were carried out at 120 days of cultivation, using: plant height (HT) stem diameter (DS), root dry matter mass (RDM), stem dry matter mass (SDM), mass leaf dry matter (LDM), total dry matter (TDM), shoot dry matter mass (SDMS). The data obtained were subjected to analysis of variance and depending on the level of significance in the F test, the study was carried out using the means test (Tukey 5%). The agronomic characteristics (HT), (DS), (RDM) and (MDMAP) were significant for N. Only (RDM) showed significant interaction for the doses of N and S. The dose 420 mg L-1 promoted the highest concentrations in the components leaf and stem. The lowest dose 105 mg L-1, N promoted the highest concentrations of S in the leaf and stem. The assimilation of S by the rosemary plants was dependent on the doses of N.

Physiological characteristics of endive, lettuce and chicory seeds as a function of spectral quality

Seedling production is a critical step in the establishment of vegetables. This work aimed to evaluate the effect of different spectral qualities on the germination and vigor of endive, lettuce, and chicory seeds. The experiment was carried out in three stages. The first stage, two cultivars of lettuce (‘Crespa Repolhuda’ and ‘Vera’) and six spectral qualities (blue LED, red LED, blue + red LED, white LED, fluorescent and dark) were evaluated; the second stage, two cultivars of chicory (‘Lisa Escarola’ and ‘Palla Rosa’) and the same spectral qualities were evaluated. In the third stage, the spectral quality of the endive cultivar ‘Pão de Açúcar’ was evaluated. The experiments were performed in a completely randomized design, with four replications of 50 seeds each. The evaluated parameters were: germination percentage, first count, germination speed index, seedling length, and fresh and dry mass. Endive, lettuce and chicory seeds germinated both in the presence or not of light so that they can be classified as neutral photos. A spectral LED of red quality fostered the development of the most significant volume of fresh mass on the endive, lettuce, and chicory. All the spectral qualities stimulated root growth. The dark, on the other hand, promoted the most significant length of the aerial part, promoting seedlings etiolation.

O Physico-chemical properties of mango pulp and cajarana blends

The mango and cajarana are pleasant-tasting fruits, yellow in color, have ascorbic acid with antioxidant properties that slow down oxidation and help the immune system to promote well-being. The production of blends can improve nutritional and sensory characteristics, combining macro and micronutrients that may be present in a higher concentration in one fruit and deficient in another, increasing the possibility of obtaining new flavors constituting a new product. The study had as objective the elaboration of blends of mango cv. espada and cajarana and to determine the physical-chemical characteristics and color parameters. Three formulations were prepared: F1 - 50% mango pulp and 50% cajarana pulp; F2 - 90% mango pulp and 10% cajarana pulp and F3 - 10% mango pulp and 90% cajarana pulp. The formulations were evaluated for physicochemical parameters of water activity, moisture content, ash, total soluble solids, pH, total titratable acidity, ascorbic acid, proteins, lipids, total sugars, reducers, non-reducers and color parameters. The data obtained were submitted to analysis of variance and comparison between means by the Tukey test. The blends caused significant changes in most of the parameters evaluated, with an increase in the moisture content, ash, total titratable acidity, proteins and lipids as the concentration of the cajarana pulp was increased. The increase in the proportion of mango pulp favored the achievement of lighter blends, with a predominance of yellowness. However, the development of blends from this study presents itself as a viable alternative for the use of fruit pulps, both in terms of nutrition, complementing the nutrient content through this mixture as a very promising product for the market.

Agronomic characterization of citrandarin fruits and seeds

In citrus cultivation, rootstocks are of fundamental importance and affect several characteristics of the variety used as canopy. Despite the great diversity within Citrus and related genera, the production of rootstocks in Brazil is restricted to a small number of varieties, making the citrus culture vulnerable to the appearance of phytosanitary problems. The aim of this study was to agronomically characterize fruits and seeds of seven citrandarins [Citrus sunki (Hayata) hort. ex Tanaka x Poncirus trifoliata cv. Rubidoux (L.) Raf.], obtained by controlled crossing. The orchard was installed in randomized blocks, with three replicates, in the municipality of Cordeirópolis, SP, where 20 fruits were collected in each replicate, obtained from free pollination of seven citrandarins, Swingle citrumelo and Rangpur lime. The following variables were evaluated: fruit mass, height, diameter, total number of seeds and percentage of viable seeds per fruit; number of embryos per seed, mass of one thousand seeds, number of seeds in 1.0 kg, final emergence rate, number of seedlings per seed, polyembryony rate, emergence speed index and seedling height at 60 days after sowing. For fruit size, the highest values were obtained for Swingle citrumelo. For number of embryos per seed, seedlings obtained through seed and polyembryony, citrandarin TSxPT 245 showed the highest values. Although citrandarin fruits had smaller size than fruits from commercial Rangpur lime and Swingle citrumelo rootstocks, characteristics related to seeds such as viability, polyembryony and emergence rate, were similar or superior, and can be considered potential new rootstocks for the production of citrus plants.

Sugar apple seedling production as a function of substrates and slow-release fertilizer

There is still a lack of studies on the effect of slow-release fertilizers and substrates on the production of high-quality sugar apple seedlings. In this context, the present study aimed to evaluate the quality and biomass of sugar apple seedlings grown in organic substrates at doses of slow-release fertilizer. The experimental design was randomized blocks in split-plot scheme, with four replicates and eleven plants per plot. Substrates were evaluated in the plots (fresh sugarcane bagasse; enriched sugarcane bagasse; coconut powder; commercial organic substrate Tropstrato®), whereas the doses of the slow-release fertilizer Osmocote® were evaluated in the subplots (0; 3; 6; 9; 12 and 15 kg m-3 of substrate). Substrates and slow-release fertilizer doses had effect on the formation of sugar apple seedlings. The effect of slow-release fertilizer is influenced by the substrate used in the formation of sugar apple seedlings. The substrate coconut powder showed the best performance for E%, NL and LAI in sugar apple plants, which reinforces its recommendation to be used in seedling production. For the studied conditions, based on the DQI, we recommend coconut powder associated with the slow-release fertilizer dose of 9 kg m-3 to produce sugar apple seedlings.

Cucumber production under organic cultivation in response to biofertilizer application

Cucumber is a vegetable species of high socioeconomic importance, whose fruits are consumed in all Brazilian regions. However, the knowledge of its organic production is still incipient. In this perspective, this study aimed to evaluate the productive performance of the Aodai cucumber under organic cultivation in response to the application of biofertilizer via soil and leaves. The experiment was conducted in the Seridó Ecological Site, Rio Branco, AC, by adopting a randomized block design in a 6x2 factorial arrangement, with four replications and eight plants per experimental unit. The treatments consisted of six concentrations of biofertilizer (0, 1, 2, 3, 4, and 5%) diluted in water, applied via foliar spraying, combined with the presence or absence of its pure application in the soil, with both methods applied at 7, 14, 21, and 28 days after sowing. The fertilizer was also applied in the soil at sowing. At the end of each harvest, the fruits were divided into two quality categories (classes 1 and 2), and then the following variables were evaluated: number of fruits per plant, mean fruit mass, yield, fruit diameter, and fruit length. There was no significant interaction of the biofertilizer application via foliar spraying or soil for any of the variables. The biofertilizer application via foliar spraying promoted a significant increase in the number of marketable fruits per plant, mean mass of total fruits, and marketable and total yields. The 3% concentration of biofertilizer diluted in water and applied on the leaves is the most efficient method to increment the cucumber yield.