Carlos Moacir Bonato

Homeopathic and larvicide effect of Eucalyptus cinerea essential oil against Aedes aegypti

ABSTRACT The aim of this work to study the homeopathic and larvicide effect of Eucalyptus cinerea essential oil on Aedes aegypti. Essential oil had high larvicide effect with LC50 and LC90 of 0.38 and 0.27 mg mL -1 , respectively. Generally, the homeopathy of essential oil affected the A. aegypti development stages. Dynamizations 6CH, 9CH and 12CH reduced the mean number of larvae when compared to that of control. Mean number of mosquitoes decreased through homeopathic dynamization 30CH. Results showed that E. cinerea essential oil was highly promising and could be used in public health system for the control of A. aegypti. Key words : Ultra-diluted; secondary metabolism; biomass; homeopathic drugs * Author for correspondence: cmbonato@uem.br INTRODUCTION Viral infection dengue, transmitted by the mosquito of the genus Aedes , is one of the main worldwide concerns in public health (Tare et al., 2004; Furtado et al., 2005), especially in tropical and subtropical countries where its incidence is very high (Cavalcanti et al., 2004). An estimated 1.3 billion people were infected with dengue according to WHO (2004). In tropical countries, Aedes aegypti is the main transmitter insect of dengue (Furtado et al., 2005), Dengue infestations have repeatedly occurred in Brazil during the last decade (Cavalcanti et al., 2004). For this, the etiological agent is an arbovirus and the main vector is the Aedes aegypti mosquito which has been found in more than 3600 municipalities in Brazil (Cives, 2002). Control of the culicide by insecticides such as temephos, malathion and phenitrothion has been the main policy adopted by public health policies (Furtado et al., 2005). However, the indiscriminate use of synthetic insecticides in agriculture and in public policy programs during the last fifty years has established resistance to insecticides, environmental pollution and contamination of humans and other living beings (Thomas et al., 2004). Resistance of the dipteran insect to conventional insecticides (Furtado et al., 2005) has been reported in different countries (Wirth and Georghiou, 1999), including Brazil (Macoris et al., 2003). Studies with natural products such as insecticides and larvicides have been undertaken for the control of mosquito Aedes , albeit with different results (Rahuman et al. 2000, Markouk et al. 2000, Ciccia et al., 2000, Tsao et al., 2002, Silva et al., 2004; Furtado et al., 2005). There are no reports in the literature on studies investigating the effects of homeopathic medicine on A. aegypti , although

Efeito de biorregulador na germinação e no vigor de sementes de soja

Os biorreguladores vegetais sao substâncias que podem incrementar o crescimento e o desenvolvimento vegetal e estimular a divisao celular, podendo interferir na germinacao das sementes. Assim, neste trabalho objetivou-se avaliar a qualidade fisiologica de sementes sob a acao de biorregulador . Utilizaram-se sementes de nove cultivares comerciais de soja (Glycine max (L.) Merrill) e tres concentracoes (400; 500 e 600 mL 100 kg -1 de sementes) do biorregulador Stimulate®, alem da testemunha, constituida de tratamento com agua destilada. Testes de germinacao e de vigor foram realizados em sementes, observando-se a percentagem de germinacao (primeira contagem e contagem final), percentagem de plântulas normais fortes, velocidade de germinacao, comprimento da raiz primaria e da parte aerea, bem como a biomassa da materia seca das plântulas. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos e quatro ou cinco repeticoes, dependendo do teste. Doses crescentes de biorregulador nao influenciaram a germinacao e a biomassa da mteria seca das sementes; entretanto, podem aumentar a velocidade de germinacao, dependendo do cultivar. Palavras-chave: Glycine max, regulador de crescimento, qualidade fisiologica.

Controle da pinta preta e efeito sobre variáveis de crescimento em tomateiro por preparados homeopáticos

Homeopathy can be an alternative to control plant diseases by means of the activation of resistance genes. The aim of this study was to evaluate the action of the homeopathic drugs Propolis, Sulphur and Ferrum sulphuricum at the dynamizations 6, 12, 30 and 60CH (centesimal hahnemanian dilutions) on the control of Alternaria solani and on growth variables. Hydroalcoholic solution at 10% and distilled water were the control treatments. At 19 days after transplanting, the 6th leaf of each plant was treated and, at 72 hours after the treatment, the 6th and the 7th leaves were inoculated with A. solani. The disease severity was assessed and the area under the disease progress curve (AUDPC) was calculated. The volume and the dry mass of roots were evaluated, as well as the fresh and the dry mass of shoots. Sulphur at 12 and 30CH, Ferrum sulphuricum at 6, 12 and 30CH and Propolis at all dilutions reduced the AUDPC by 17% to 49%. Sulphur at 60CH and hydroalcoholic solution at 10% had a systemic effect on resistance induction. Propolis at 30 and 60CH increased the volume of roots by 39% and 33%, respectively, the fresh mass of shoots by 35% (30CH) and the dry mass of roots by 38% (30CH). Sulphur at all dilutions increased the mass of shoots by 23% to 37%, while at 60CH it increased by 59% the mass of roots, which also occurred for Ferrum sulphuricum at 60CH (65% increment). These results indicate that homeopathic drugs can control early blight and increase the growth of tomato plants.

Amadurecimento de frutos de cubiu (Solanum sessiliflorum Dunal) tratados com Etefon

ABSTRACT The objective of the present work was to evaluate postharvest quality of cubiu ( Solanum sessiliflorum ) fruits during ripening after Ethephon treatment. Fruits from the varieties Santa Luzia and Thais were harvested at green-mature stage, washed and sprayed until run off with Ethephon (0 e 1000 mg L -1 ). At every three days, during 12 days, the following analyses were performed: pericarp firmness, pH, total soluble solid content, total titratable acidity (ATT), water content and ashes. CO 2 and ethylene production were evaluated daily for 12 days, together with the loss of fresh matter and color evolution, at every three days, always the same fruit group. The experiment was arranged in a complete randomized design. Data were examined by analysis of variance and regression analysis. There was loss of pericarp firmness with time of postharvest storage, with decrease in pH, increase in ATT and loss of fresh matter. Ethephon promoted small changes in the internal quality of fruits, whereas it was efficient to induce degreening of fruit peel, which can be verified by the lower color angles and higher chromaticity and brightness. Respiration rates and ethylene production of the fruit suggest that cubiu has non-climateric behavior.

Mineral composition and dry mass production of the corn plants in response to phosphorus sources and aluminum concentration

The corn plants were evaluated with different phosphate fertilizer sources and aluminum (Al) concentrations in a sandy substrate. A totally randomized experiment design was set up with two corn plants in the pots containing 2 kg of a sandy substrate, two phosphate sources (Triple Super Phosphate - TSP or Arad Phosphate - AP) and four Al concentrations. When Al concentrations increased, pH (CaCl2) substrate values decreased. There was an increase in the calcium and phosphorus contents in the sandy substrates that received the TSP and AP sources. The calcium, magnesium, phosphorus, and potassium concentrations of the corn plants shoot were higher in the TSP than without P and AP sources. When the Al concentration increased, the concentration values of the former elements decreased. The dry mass production of the corn plants responded positively to P sources. As the Al concentration increased, the dry mass values decreased significantly in the TSP source.

Increased gibberellin levels enhance light capture efficiency in tobacco plants and promote dry matter accumulation

Plants are constantly subjected to light variations in the environment, and plant hormones are one of the intermediaries between environmental signals and physiological responses. Among these responses, gibberellins (GAs) promote physiological changes that regulate plant growth and development patterns. Morphological changes, such as internode length and light absorbance maximization, are likely to induce plant performancexa0increases leading to biomass accumulation. In this context, the hypothesis tested herein was that manipulation of GA levels can influence plant biomass accumulation by modifying thexa0internode length and, consequently, light capture efficiency, with direct effects on plant biomass accumulation rates evaluated by unit leaf rate and growth analysis. For this, tobacco plants were cultivated in high- and low- irradiance environments under different gibberellic acid (GA3) and paclobutrazol (PAC, a GA biosynthesis inhibitor) concentrations as a tool to manipulate thexa0internode length and plantxa0height. Dry matter accumulation was evaluated in response to light capture efficiency and interception, energy content and anatomical stem changes. The results obtained and supported by a principal component analysis indicate that GAs are capable of promoting phenotypic changes in plants grown in both high and low irradiance environments, and that they trigger responses relatedxa0with biomass accumulation by maximizing light capture performance in response to internode length in tobacco plants. The data presented herein emphasize that GAs are essential in promoting growth and biomass accumulation, especially in low irradiance environments.

Nitrogen-improved photosynthesis quantum yield is driven by increased thylakoid density, enhancing green light absorption

A nitrogen supply is necessary for all plants. The multifaceted reasons why this nutrient stimulates plant dry weight accumulation are assessed herein. We compared tomato plants grown in full sunlight and in low light environments under four N doses and evaluated plant growth, photosynthetic and calorimetric parameters, leaf anatomy, chloroplast transmission electron microscopy (TEM) and a high resolution profile of optical leaf properties. Increases in N supplies allow tomato plants to grow faster in low light environments (91.5% shading), displaying a robust light harvesting machinery and, consequently, improved light harvesting efficiency. Ultrastructurally, high N doses were associated to a high number of grana per chloroplast and greater thylakoid stacking, as well as high electrodensity by TEM. Robust photosynthetic machinery improves green light absorption, but not blue or red. In addition, low construction and dark respiration costs were related to improved total dry weight accumulation in shade conditions. By applying multivariate analyses, we conclude that improved green light absorbance, improved quantum yield and greater palisade parenchyma cell area are the primary components that drive increased plant growth under natural light-limited photosynthesis.

Increased Gibberellins and Light Levels Promotes Cell Wall Thickness and Enhance Lignin Deposition in Xylem Fibers

Light intensity and hormones (gibberellins; GAs) alter plant growth and development. A fine regulation triggered by light and GAs induces changes in stem cell walls (CW). Cross-talk between light-stimulated and GAs-induced processes as well as the phenolic compounds metabolism leads to modifications in lignin formation and deposition on cell walls. How these factors (light and GAs) promote changes in lignin content and composition. In addition, structural changes were evaluated in the stem anatomy of tobacco plants. GA3 was sprayed onto the leaves and paclobutrazol (PAC), a GA biosynthesis inhibitor, via soil, at different irradiance levels. Fluorescence microscopy techniques were applied to detect lignin, and electron microscopy (SEM and TEM) was used to obtain details on cell wall structure. Furthermore, determination of total lignin and monomer contents were analyzed. Both light and GAs induces increased lignin content and CW thickening as well as greater number of fiber-like cells but not tracheary elements. The assays demonstrate that light exerts a role in lignification under GA3 supplementation. In addition, the existence of an exclusive response mechanism to light was detected, that GAs are not able to replace.

Homeopatias de óleos essenciais sobre a germinação de esporos e indução de fitoalexinas

A homeopatizacao de oleos essenciais revela-se como uma alternativa para o controle de fitopatogenos e na inducao de compostos de defesa em plantas, como as fitoalexinas. Neste sentido, o objetivo do trabalho foi de avaliar o efeito de solucoes dinamizadas de Eucalyptus citriodora (EC) e Cymbopogon citratus (CC) na germinacao de conidios de Alternaria solani e Corynespora cassiicola e na producao de fitoalexinas em soja. Para os testes foram utilizados os tratamentos homeopaticos: 6CH, 12CH, 30CH, 60CH, 100CH e 200CH de ambos os oleos. A porcentagem de germinacao foi determinada 4 horas apos incubacao dos patogenos na presenca dos tratamentos, em placas tipo Elisa a 25 oC, e feita contagem de esporos em microscopio optico. Para fitoalexinas, cotiledones de soja oriundos de sementes cultivadas em areia esteril foram cortados na superficie inferior e submetido aos tratamentos, permanecendo no escuro por 20 horas. A gliceolina formada foi extraida e determinada em espectrofotometro. Todas as dinamizacoes aplicadas reduziram a germinacao de ambos patogenos, chegando a reducao de 59% em A. solani e 42% em C. cassiicola por CC 30CH. As dinamizacoes testadas nao foram eficientes para inducao de gliceolina, indicando maior potencial dos tratamentos sobre os patogenos em comparacao a elicitacao destes compostos de defesa. Baseando-se nestes resultados, e possivel evidenciar o potencial de tratamentos homeopaticos no controle de A. solani e C. cassiicola. O processo de homeopatizacao manteve as propriedades antimicrobianas dos oleos testados.

Activation of biochemical defense mechanisms in bean plants for homeopathic preparations

To evaluate the potential elicitor of homeopathic preparations on bean plants cv Carioca, homeopathics of Corymbia citriodora, Calcarea carbonica, Silicea and Sulphur in dynamisations 12, 24, 30 and 60CH were applied by pulverization throughout the aerial part. Samples of leaf tissue were taken at 6, 12, 24, 48 and 126 h after the treatment (HAT) to analyze the activity of peroxidase (POX), catalase (CAT), chitinase (CHI) and uf062-1.3-glucanase (GLU), and fifteen days after the application for the total contents of chlorophyll a and b. For the induction of phytoalexin phaseolin, seeds of the same genotype were germinated in the presence of respective treatments, and the production of phytoalexin quantified spectrophotometrically. All treatments increased the activity of POX, CAT, QUI and GLU, in at least one of the schedules evaluated in comparison to the control. The treatments C. citriodora and C. carbonic did not alter the contents of chlorophyll but induced the accumulation of phaseolin. Silicea and Sulphur caused significant reduction in the levels of chlorophyll a and b. The induction values were superior to the trading inductor (harpin), indicating that these homeopathies may come to be utilized as elicitor treatments on bean plants. The results indicate the potential of the treatments applied in the induction of biochemical mechanisms of defense in the bean plants.