Albedo and estimates of net radiation for green beans under polyethylene cover and field conditions

This paper describes the albedo (r) and estimates of net radiation and global solar irradiance for green beans crop (Phaseolus vulgaris L.), cultivated in greenhouse with cover of polyethylene and field conditions, in Botucatu, SP, Brazil (22º 54' S; 48º 27' W; 850 m). The solar global irradiance (Rg) and solar reflected radiation (Rr) were used to estimate the albedo through the ratio between Rr and Rg. The diurnal curves of albedo were obtained for days with clear sky and partially cloudy conditions, for different phenological stages of the crop. The albedo ranged with the solar elevation, the environment and the phenological stages. The cloudiness range have almost no influence on the albedo diurnal amount. The estimation of radiation were made by linear regression, using the global solar irradiance (Rg) and net short-waves radiation (Rc) as independent variables. All estimates of radiation showed better adjustment for specific phenological periods compared to the entire crop growing cycle. The net radiation in the greenhouse has been estimated by the global solar irradiance measured at field conditions.

Rearing the southern green stink bug using an artificial dry diet and an artificial plant

Laboratory and greenhouse studies were conducted with an artificial dry diet to rear nymphs, and with an artificial plant as substrate for egg laying by the southern green stink bug, Nezara viridula (L.). The artificial diet was composed of: soybean protein (15 g); potato starch (7.5 g); dextrose (7.5 g); sucrose (2.5 g); cellulose (12.5 g); vitamin mixture (niacinamide 1 g, calcium pantothenate 1 g, thiamine 0.25 g, riboflavin 0.5 g, pyridoxine 0.25 g, folic acid 0.25 g, biotin 0.02 mL, vitamin B12 1 g - added to 1,000 mL of distilled water) (5.0 mL); soybean oil (20 mL); wheat germ (17.9 g); and water (30 mL). Nymphs showed normal feeding behavior when fed on the artificial diet. Nymphal development time was longer than or similar to that of nymphs fed on soybean pods. Total nymphal mortality was low (ca. 30%), both for nymphs reared on the artificial diet, and for nymphs fed on soybean pods. At adult emergence, fresh body weights were significantly (P<0.01) less on the artificial diet than on soybean pods. Despite the lower adult survivorship and fecundity on artificial plants than on soybean plants, it was demonstrated for the first time that a model simulating a natural plant, can be used as a substrate for egg mass laying, in conjunction with the artificial diet.

Enchimento de sementes em linhas quase-isogênicas de trigo com presença e ausência do caráter "stay-green"

O caráter "stay-green" (permanência da cor verde nas plantas) tem sido utilizado para reduzir a senescência em trigo, resultando no aumento funcional da área foliar, e, conseqüentemente, na elevação da taxa e da duração do enchimento da semente. O objetivo deste trabalho foi analisar a taxa de acúmulo de matéria seca e a duração do período de enchimento da semente de linhas quase-isogênicas de trigo diferenciadas quanto à presença e ausência do caráter "stay-green". O experimento foi conduzido no Centro Experimental da Palma, Pelotas, RS. Foram utilizadas quatro linhas quase-isogênicas: F6-SG e F6-SZ, no ano de 2000 e F7-SG e F7-SZ no ano 2001, com cinco repetições. O caráter "stay-green" permitiu maior deposição de reservas na semente na fase próxima do ponto de maturidade fisiológica. A duração do período de enchimento da semente esteve associada ao acúmulo de matéria seca na semente, promovendo um maior peso médio da semente. Assim, o progresso do caráter taxa de enchimento da semente poderá ser obtido por meio de seleções de plantas com maior peso médio da semente.

Green manure incorporation timing for organically grown broccoli

The objective of this work was to determine the effect of incorporation timing of the velvet bean (Stizolobium cinereum) (GM) on both organic broccoli yield and N status. Mineral N content in the soil, biologically fixed N recovery by broccoli, GM biomass decomposition and N release kinetics were also determined. Plots were fertilized with 12 Mg ha-1 of organic compost and received GM either at 0, 15, 30 or 45 days after transplant. Other treatments were compost (12 or 25 Mg ha-1), GM, mineral fertilizers and control (no fertilizer). The data were collected in four completely randomized blocks. GM decomposition increased mineral N content in soil as rapidly as mineral fertilizer or the supply of 25 Mg ha-1 of compost. The N half-life in GM (24 days) is smaller than the mass half-life (35 days) and the biological fixation contributed with 23.6% of N present in the aboveground biomass of broccoli. The result suggests a higher synchrony between the crop relative growth rate and N release from the GM when incorporated at crop early growth stage. The incorporation of GM until 15 days after transplanting replaces 50% of the highest compost dose, without yield loss.

Phosphorus utilization by corn as affected by green manure, nitrogen and phosphorus fertilizers

The objective of this work was to evaluate the utilization by corn plants of P from triple superphosphate fertilizer labeled with 32P (32P‑TSP), and of P from soil as affected by N rates and by the green manures (GM) sunn hemp (Crotalaria juncea) and millet (Pennisetum glaucum). The experiment was carried out using pots filled with 5 kg Oxisol (Rhodic Hapludox). A completely randomized design was used, in a 4x4x2 factorial arrangement, with four replicates. The treatments were: four P rates as TSP (0, 0.175, 0.350, and 0.700 g P per pot); four N rates as urea (0, 0.75, 1.50, and 2.25 g N per pot); and sunn hemp or millet as green manure. The additions of N and P by the GM were taken into account. After grain physiologic maturation, corn dry matter, P contents, accumulated P, and P recovery in the different treatments were measured. 32P‑TSP recovery by corn increased with N increasing rates, and decreased with increasing rates of 32P‑TSP. The mineral fertilizer provides most of the accumulated P by corn plants. The recovery of 32P‑TSP by corn was 13.12% in average. The green manure species influence the assimilation of 32P‑TSP by the plants.

Desempenho per se e parâmetros genéticos de linhagens de trigo com expressão do caráter "stay‑green"

O objetivo deste trabalho foi determinar o desempenho per se e os parâmetros genéticos de caracteres de interesse, em linhagens de trigo que expressam ou não o caráter "stay‑green". O experimento foi conduzido em 2003, 2004 e 2005, em delineamento experimental de blocos ao acaso, com três repetições. Foram avaliadas 32 linhagens irmãs de trigo, 15 com e 17 sem o caráter "stay‑green". As linhagens portadoras desse caráter apresentaram maior produtividade de grãos, maior número de grãos por espiga e menor massa de mil grãos. Além disso, as herdabilidades da produtividade e da massa de grãos foram maiores nessas linhagens, o que revelou menor influência de variações ambientais sobre a expressão desses caracteres. O caráter "stay‑green" contribui para o aumento da produtividade e da estabilidade produtiva do trigo.

Yield and nutritional composition of oyster mushroom strains newly introduced in Bangladesh

The objective of this work was to evaluate yield and chemical composition of oyster mushroom strains newly introduced in Bangladesh. Strains of Pleurotus high‑king (strain PHK), P. ostreatus (strain PO2), and P. geesteranus (strains PG1 and PG3) were evaluated as to yield components and proximate composition. Pleurotus ostreatus was used as control. Pleurotus high‑king showed fastest growth of primordia, but moderate flush of effective fruiting bodies. Pleurotus geesteranus (PG1) showed higher economic yield and biological performance, and better chemical composition, especially in terms of protein and mineral contents. Pleurotus geesteranus (PG1) shows better performance than P. ostreatus (PO2), the most commercially cultivated edible species in Bangladesh, and, therefore, it should be recommended for commercial cultivation.

Nutritional potential of green banana flour obtained by drying in spouted bed

This study evaluated the chemical composition of peeled and unpeeled green banana Cavendish (AAA) flour obtained by drying in spouted bed, aiming at adding nutritional value to food products. The bananas were sliced and crushed to obtain a paste and fed to the spouted bed dryer (12 cm height and T = 80 ºC) in order to obtain flour. The flours obtained were subjected to analysis of moisture, protein, ash, carbohydrates, total starch, resistant starch, fiber. The green banana flours, mainly unpeeled, are good sources of fiber and resistant starch with an average of 21.91g/100g and 68.02g/100g respectively. The protein content was found in an average of 4.76g/100g, being classified as a low biological value protein with lysine as the first limiting amino acid. The results showed that unpeeled green banana flour obtained by spouted bed drying can be a valuable tool to add nutritional value to products in order to increase their non-digestible fraction.

Caracterização ácido-base da superfície de espécies mistas da alga Spirulina através de titulação potenciométrica e modelo de distribuição de sítios discretos

Acid base properties of mixed species of the microalgae Spirulina were studied by potentiometric titration in medium of 0.01 and 0.10 mols L-1 NaNO3 at 25.0±0.10 C using modified Gran functions or nonlinear regression techniques for data fitting. The discrete site distribution model was used, permitting the characterization of five classes of ionizable sites in both ionic media. This fact suggests that the chemical heterogeneity of the ionizable sites on the cell surface plays a major role on the acid-base properties of the suspension in comparison to electrostatic effects due to charge-charge interactions. The total of ionizable sites were 1.75±0.10 and 1.86±0.20 mmolsg-1 in ionic media of 0.01 and 0.10 mols L-1 NaNO3, respectively. A major contribution of carboxylic groups was observed with an average 34 and 22% of ionizable sites being titrated with conditional pcKa of 4.0 and 5.4, respectively. The remaining 44% of ionizable sites were divided in three classes with averaged conditional pcKa of 6.9, 8.7 and 10.12, which may be assigned respectively to imidazolic, aminic, and phenolic functionalities.

Economia de átomos, engenharia molecular e catálise organometálica bifásica: conceitos moleculares para tecnologias limpas

For economical and ecological reasons, synthetic chemists are confronted with the increasing obligation of optimizing their synthetic methods. Maximizing efficiency and minimizing costs in the production of molecules and macromolecules constitutes, therefore, one of the most exciting challenges of synthetic chemistry. The ideal synthesis should produce the desired product in 100% yield and selectivity, in a safe and environmentally acceptable process. In this highlight the concepts of atom economy, molecular engineering and biphasic organometallic catalysis, which address these issues at the molecular level for the generation of "green" technologies, are introduced and discussed.

"Green chemistry": os 12 princípios da química verde e sua inserção nas atividades de ensino e pesquisa

Green chemistry ¾ defined as the design, development, and application of chemical processes and products to reduce or eliminate the use and generation of substances hazardous to human health and the environment. This article summarizes the 12 principles of green chemistry, describing how they have been applied to the academic, industrial and research activities around the world.

Química verde, os desafios da química do novo milênio

The fundamental concepts of the green chemistry are highlighted in order to present the enormous number of challenges to develop a new chemistry in research, industry and education. The practice of an environmental friendly chemistry are presented to improve the economics of chemical manufacturing and to enhance the much-tarnished image of chemistry and to present the opportunities to discover and apply this new chemistry. The challenges and opportunities of green chemistry in the world and Brazil are introduced and discussed in this report.

Electrochemistry and green chemical processes: electrochemical ozone production

After an introductory discussion emphasising the importance of electrochemistry for the so-called Green Chemical Processes, the article presents a short discussion of the classical ozone generation technologies. Next a revision of the electrochemical ozone production technology focusing on such aspects as: fundamentals, latest advances, advantages and limitations of this technology is presented. Recent results about fundamentals of electrochemical ozone production obtained in our laboratory, using different electrode materials (e.g. boron doped diamond electrodes, lead dioxide and DSAÒ-based electrodes) also are presented. Different chemical processes of interest to the solution of environmental problems involving ozone are discussed.

4-(hidroximetil)-benzenossulfonato de potássio: metabólito inédito isolado da alga marinha Bostrychia tenella (Rhodomelaceae, ceramiales)

Chemical investigation of the dichloromethane/methanol extract of the marine alga Bostrychia tenella has led to the isolation of two aromatic compounds, the new sulfate metabolite potassium 4-(hydroxymethyl)-benzenosulfonate (1) and the compound 1-methoxyphenethyl alcohol (2), described previously as a synthetic product. Their structures were determined by spectroscopic methods including NMR, MS, IR and by comparison with literature data.

Supercritical CO2 recovery of caffeine from green coffee oil: new experimental solubility data and modeling

The caffeine solubility in supercritical CO2 was studied by assessing the effects of pressure and temperature on the extraction of green coffee oil (GCO). The Peng-Robinson¹ equation of state was used to correlate the solubility of caffeine with a thermodynamic model and two mixing rules were evaluated: the classical mixing rule of van der Waals with two adjustable parameters (PR-VDW) and a density dependent one, proposed by Mohamed and Holder² with two (PR-MH, two parameters adjusted to the attractive term) and three (PR-MH3 two parameters adjusted to the attractive and one to the repulsive term) adjustable parameters. The best results were obtained with the mixing rule of Mohamed and Holder² with three parameters.