Essential oil of mustard to control Rhizoctonia solani causing seedling damping off and seedling blight in nursery

The essential oil extracted from mustard (Brassica rapa) seeds was evaluated for its effect on suppression of Rhizoctonia solani growth in vitro, and in field soils, for reducing saprophytic substrate colonization and seedling damping off and blight using snap beans as indicator plant, the in vitro growth was completely inhibited at a concentration of 50 mul/l. The saprophytic substrate colonization in soils 24 h after treatment was drastically reduced to 45% at 150 mul/kg soil concentration, in contrast to 100% colonization at concentrations of 0, 50, or 75 mul/kg. This recovery rate gradually declined to 6% and 60%, respectively, in nine days. A control of pre and post-emergence seedling damping off and blight in common beans (Phaseolus vulgaris), without any apparent phytotoxic effect was achieved by irrigating R. solani infested soils with water containing the emulsified essential oil to provide 150 mul/l soil volume ten days prior to planting, gave over 95%. The effect of the mustard essential oil was not influenced by the physical soil texture, and it appears to be a good substitute for methyl bromide fumigation in nurseries for seedling production.

Identification of the major fungitoxic component of cinnamon bark oil

The study was done to identify the most active fungitoxic component of cinnamon bark (Cinnamomum zeylanicum) oil that can be used as a marker for standardization of cinnamon extract or oil based natural preservative of stored seeds. Aspergillus flavus and A. ruber were used as test fungi. The hexane extracted crude oil and the hydro-distilled essential oil from cinnamon bark had complete growth inhibition concentration (CGIC) of 300 and 100 µl/l, respectively. Both oils produced three fractions on preparative thin layer silica-gel chromatography plates. The fraction-2 of either oil was the largest and most active, with CGIC of 200 µl/l, but the fungitoxicity was also retained in the other two fractions. The fraction-1 and 3 of the crude oil reduced growth of both the fungal species by 65%, and those of distilled oil by 45% at 200 µl/l. The CGIC of these fractions from both the sources was above 500 µl/l. The gas chromatography and mass spectrometry (GC-MS) of the fraction-2 of the hexane extract revealed that it contained 61% cinnamaldehyde, 29% cinnamic acid, and two minor unidentified compounds in the proportion of 4% and 6%. The GC-MS of the fraction-2 of the distilled oil revealed that it contained 99.1% cinnamaldehyde and 0.9% of an unidentified compound. The CGIC of synthetic cinnamaldehyde was 300 µl/l and that of cinnamic acid above 500 µl/l. The 1:1 mixture of cinnamaldehyde and cinnamic acid had CGIC of 500 µl/l. The data revealed that cinnamaldehyde was the major fungitoxic component of hexane extract and the distilled essential oil of cinnamon bark, while other components have additive or synergistic effects on total fungitoxicity. It is suggested that the natural seed preservative based on cinnamon oil can be standardized against cinnamaldehyde.

Effect of extracts from citric biomass, rusted coffee leaves and coffee berry husks on Phoma costarricencis of coffee plants

Phoma leaf spot, caused by Phoma costarricensis poses a serious threat to coffee (Coffea arabica) production, especially in the highlands of the state of Minas Gerais, Brazil. Extracts of citric biomass, coffee berry husks and coffee leaves severely affected by rust caused by Hemileia vastatrix, were evaluated against P. costarricensis. In an in vitro assay, aqueous extracts of rusted leaves and berry husks plus the commercial extracts based on citric biomass named Ecolife® and Agromil® were tested at various dilutions on the mycelial growth inhibition of P. costarricensis. In vivo, coffee seedlings maintained in glasshouse, were sprayed with these extracts seven days before inoculation of P. costarricensis. Only extracts from citric biomass had inhibitory effects on the fungus. In vivo, Ecolife® (5 ml/l), Agromil® (5 g/l) and the aqueous extract of rusted coffee leaves (dilution 1:6) reduced Phoma leaf spot. Both, Ecolife® and the extract of rusted coffee leaves were significantly more effective in reducing the area under the lesion progress curve when applied at lower doses, indicating a possible effect on the induction of resistance.

Origin of oil in the Wilmington field in California

No presente trabalho, o autor trata da formação de campo petrolífero que se teria formado às expensas de organismos planctónicos, misturados com areia das dunas, material esse que teria sido transportado pelo vento. Refere-se, assim, o autor, ao campo petrolífero de "Wilmington", situado na Ilha Terminal, ao sul de Los Angeles, California. Esse campo, que já fora descrito, em 1943, por GILLULY & GRANT, faz parte do Mioceno e do Plioceno inferior, achando-se separado dos schistos Jurássicos metamórficos, por uma discordância localizada a 6.000 pés de profundidade. O conjunto das camadas petrolíferas alcança espessura de 1 .500 pés, sendo cada uma delas separada das outras por estratos do "siltstone" (siltito). O tamanho dos grãos, nos dois tipos de rochas, é o de depósitos eólicos, mas, ao contrário do que acontece em depósitos sub-aéreos, esses grãos são angulosos ou sub-angulosos. De acordo com MCNAUGHTON , esses depósitos se teriam formado em profundidade crescente, de 200 a 5.000 pés; esse fato, relacionado com as dimensões dos grãos, leva a crer que o material tenha sido transportado pelo vento. A sedimentação deu-se longe da costa, de maneira muito lenta, provavelmente em consequência de tempestades de excepcional intensidade. O petróleo teria sido produzido por organismos planctónicos que se teriam misturado com areia das dunas, sendo a velocidade da sedimentação desta, muito menor. Os cálculos indicam que foram armazenados somente 23% dos hidrocarbonetos que caíram sobre a areia de sedimentação, sob a forma de organismos mortos. M. V.

Production of biodiesel from babassu oil using methanol-ethanol blends

Maranhão state in Brazil presents a big potential for the cultivation of several oleaginous species, such as babassu, soybean, castor oil plant, etc... These vegetable oils can be transformed into biodiesel by the transesterification reaction in an alkaline medium, using methanol or ethanol. The biodiesel production from a blend of these alcohols is a way of adding the technical and economical advantages of methanol to the environmental advantages of ethanol. The optimized alcohol blend was observed to be a methanol/ethanol volume ratio of 80 % MeOH: 20 % EtOH. The ester content was of 98.70 %, a value higher than the target of the ANP, 96.5 % (m/m), and the biodiesel mass yield was of 95.32 %. This biodiesel fulfills the specifications of moisture, specific gravity, kinematic viscosity and percentages of free alcohols (methanol plus ethanol) and free glycerin.

Adsorption isotherm studies of BOD, TSS and colour reduction from palm oil mill effluent (POME) using boiler fly ash

Palm oil is one of the two most important vegetable oils in the world's oil and fats market. The extraction and purification processes generate different kinds of waste generally known as palm oil mill effluent (POME). Earlier studies had indicated the possibility of using boiler fly ash to adsorb impurities and colour in POME treatment. The adsorption treatment of POME using boiler fly ash was further investigated in detail in this work with regards to the reduction of BOD, colour and TSS from palm oil mill effluent. The amount of BOD, colour and TSS adsorbed increased as the weight of the boiler fly ash used was increased. Also, the smaller particle size of 425µm adsorbed more than the 850µm size. Attempts were made to fit the experimental data with the Freundlich, Langmuir and Dubinin-Radushkevich isotherms. The R² values, which ranged from 0.8974-0.9898, 0.8848-0.9824 and 0.6235-0.9101 for Freundlich, Langmuir and Dubinin-Radushkevich isotherms respectively, showed that Freundlich isotherm gave a better fit followed by Langmuir and then Dubinin-Radushkevich isotherm. The sorption trend could be put as BOD > Colour > TSS. The apparent energy of adsorption was found to be 1.25, 0.58 and 0.97 (KJ/mol) for BOD, colour and TSS respectively, showing that sorption process occurs by physiosorption. Therefore, boiler fly ash is capable of reducing BOD, Colour and TSS from POME and hence could be used to develop a good adsorbent for POME treatment.

Vírus da mancha anular do cafeeiro (Coffee ringspot virus - CoRSV): influência na qualidade da bebida e na produção de grãos de café

A mancha anular do cafeeiro, causada pelo Coffee ringspot virus (CoRSV) que é transmitido pelo ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae), tem sido observada em altas incidências em várias regiões cafeeiras do Estado de Minas Gerais. O CoRSV causa manchas cloróticas arrendondadas ou irregulares nas folhas, caules e frutos. Foi feita uma avaliação do efeito da infecção de frutos do cafeeiro pelo CoRSV na qualidade da bebida por meio de teste bioquímico e de degustação, e também na eventual perda de peso nos grãos. Testes revelaram que grãos provenientes de frutos de café infectados pelo CoRSV apresentavam menor teor de açúcares redutores e maior condutividade elétrica. Houve também depreciação na qualidade de bebida gerada pelos frutos infectados por meio do teste de degustação (teste de xícara). O peso médio dos grãos provenientes de frutos manchados foi cerca de 5% menor do que dos grãos de frutos sem sintomas.

Incubation period of Hemileia vastatrix in coffee plants in Brazil simulated under climate change

Risk analysis of climate change on plant diseases has great importance for agriculture since it allows the evaluation of management strategies to minimize future damages. This work aimed to simulate future scenarios of coffee rust (Hemileia vastatrix) epidemics by elaborating geographic distribution maps using a model that estimates the pathogen incubation period and the output from three General Circulation Models (CSIRO-Mk3.0, INM-CM3.0, and MIROC3.2.medres). The climatological normal from 1961-1990 was compared with that of the decades 2020s, 2050s and 2080s using scenarios A2 and B1 from the IPCC. Maps were prepared with a spatial resolution of 0.5 × 0.5 degrees of latitude and longitude for ten producing states in Brazil. The climate variables used were maximum and minimum monthly temperatures. The maps obtained in scenario A2 showed a tendency towards a reduction in the incubation period when future scenarios are compared with the climatological normal from 1961-1990. A reduction in the period was also observed in scenario B1, although smaller than that in scenario A2.

GFP-fluorescent protein on the study of blister spot in coffee plants

In Brazil, Colletotrichum gloeosporioides is associated with a complex of symptoms in coffee culture. Although this pathogen had its pathogenesis observed and identified, its importance has still been questioned due to its several endophytic forms, raising doubts as to the real importance of the pathosystem. The aim of this study was to demonstrate, by using an isolate transformed with the gene gfp, the infection and colonization capability of C. gloeosporioides in coffee seedlings. After the fourth day of inoculation, manifestation of symptoms as punctual necrosis could be observed, which progressed during the evaluation period, culminating in the death of seedlings. Epifluorescence microscopy confirmed the presence of the pathogen in the seedlings, as well as the visualization of internal colonization of tissues, acervulus formation and conidium production, confirming that it was responsible for the observed symptoms.

Anatomical changes on coffee leaves infected by Pseudomonas syringae pv. garcae

ABSTRACTAlthough poorly studied, the bacterial halo blight is an important disease in the major coffee-producing states of Brazil. External damage and anatomical changes on leaves were measured in seedlings of Coffea arabica cv. Mundo Novo, susceptible to Pseudomonas syringae pv. garcae, by using histological sections obtained at 10 and 20 days after inoculation (DAI). The changes on the epidermis were smaller than the lesions measured in the mesophyll, irrespective of the evaluated colonization period, showing that the internal damage caused by the bacterium represent twice the damage observed externally. From the inoculation site, lysis occurred on the epidermal cells and on the palisade and spongy parenchyma cells, with strong staining of their cellular contents, as well as abnormal intercellular spaces in the palisade parenchyma, hypertrophy and hyperplasia of mesophyll cells and partial destruction of chloroplasts. Additionally, this study revealed the presence of inclusion bodies in epidermal and mesophyll cells. Bacterial masses were found in the apoplast between and within mesophyll cells. Bacteria were also observed in the bundle sheath and vascular bundles and were more pronounced at 20 DAI, not only near the inoculation site but also in distant areas, suggesting displacement through the vascular system. These results can be useful to understand this plant-pathogen interaction.

Measurement and simulation of solar radiation availability in relation to the growth of coffee plants in an agroforestry system with rubber trees

Solar radiation is an important factor for plant growth, being its availability to understory crops strongly modified by trees in an Agroforestry System (AFS). Coffee trees (Coffea arabica - cv. Obatã IAC 1669-20) were planted at a 3.4 x 0.9 m spacing inside and aside rows of monocrops of 12 year-old rubber trees (Hevea spp.), in Piracicaba-SP, Brazil (22º42'30" S, 47º38'00" W - altitude: 546m). One-year-old coffee plants exposed to 25; 30; 35; 40; 45; 80; 90; 95 and 100% of the total solar radiation were evaluated according to its biophysical parameters of solar radiation interception and capture. The Goudriaan (1977) adapted by Bernardes et al. (1998) model for radiation attenuation fit well to the measured data. Coffee plants tolerate a decrease in solar radiation availability to 50% without undergoing a reduction on growth and LAI, which was approximately 2m².m-2 under this condition. Further reductions on the availability of solar radiation caused a reduction in LAI (1.5m².m-2), thus poor land cover and solar radiation interception, resulting in growth reduction.

Coffee water use in agroforestry system with rubber trees

Water uptake and use by plants are essentially energy processes that can be largely modified by percentage of soil cover, plant type; foliage area and its distribution; phenological stage and several environmental factors. Coffee trees (Coffea arabica - cv. Obatã IAC 1669-20) in Agrforestry System (AFS) spaced 3.4x0.9m apart, were planted inside and along rows of 12- year-old rubber trees (Hevea spp.) in Piracicaba-SP, Brazil (22 42'30" S, 47 38'00" W - altitude: 546m). Sap flow of one-year-old coffee plants exposed to 35; 45; 80; 95 and 100% of total solar radiation was estimated by the heat balance technique (Dynamax Inc.). Coffee plants under shade showed greater water loss per unit of incident irradiance. On the other hand, plants in monocrop (full sun) had the least water loss per unit of incident irradiance. For the evaluated positions average water use was (gH2O.m-2Leaf area.MJ-1): 64.71; 67.75; 25.89; 33.54; 27.11 in Dec./2002 and 97.14; 72.50; 40.70; 32.78; 26.13 in Feb./2003. This fact may be attributed to the higher stomata sensitivity of the coffee plants under more illuminated conditions, thus plants under full sun presented the highest water use efficiency. Express transpiration by leaf mass can be a means to access plant adaptation to the various environments, which is inaccessible when the approach is made by leaf area.

Use of data mining and spectral profiles to differentiate condition after harvest of coffee plants

This study aimed at identifying different conditions of coffee plants after harvesting period, using data mining and spectral behavior profiles from Hyperion/EO1 sensor. The Hyperion image, with spatial resolution of 30 m, was acquired in August 28th, 2008, at the end of the coffee harvest season in the studied area. For pre-processing imaging, atmospheric and signal/noise effect corrections were carried out using Flaash and MNF (Minimum Noise Fraction Transform) algorithms, respectively. Spectral behavior profiles (38) of different coffee varieties were generated from 150 Hyperion bands. The spectral behavior profiles were analyzed by Expectation-Maximization (EM) algorithm considering 2; 3; 4 and 5 clusters. T-test with 5% of significance was used to verify the similarity among the wavelength cluster means. The results demonstrated that it is possible to separate five different clusters, which were comprised by different coffee crop conditions making possible to improve future intervention actions.

Determination of the influence of the variation of reducing and non-reducing sugars on coffee quality with use of artificial neural network

The present study aimed at evaluating the use of Artificial Neural Network to correlate the values resulting from chemical analyses of samples of coffee with the values of their sensory analyses. The coffee samples used were from the Coffea arabica L., cultivars Acaiá do Cerrado, Topázio, Acaiá 474-19 and Bourbon, collected in the southern region of the state of Minas Gerais. The chemical analyses were carried out for reducing and non-reducing sugars. The quality of the beverage was evaluated by sensory analysis. The Artificial Neural Network method used values from chemical analyses as input variables and values from sensory analysis as output values. The multiple linear regression of sensory analysis values, according to the values from chemical analyses, presented a determination coefficient of 0.3106, while the Artificial Neural Network achieved a level of 80.00% of success in the classification of values from the sensory analysis.

Impact of irrigation on yield and energy balance of the production of oil and cake of two sunflower varieties

The energy balance for the production of sunflower oil and cake was carried out during the agricultural and industrial stage phase, where it was considered a cold extraction by hydraulic pressing, with the plant location in a rural area with a radius of 30km range. Data on productivity was used in two varieties of sunflower (Helio 358 and Aguará 04) grown in different seasons (2007/2008, 2008/2009), under different irrigation levels. Data showed that irrigation resulted in an increase in productivity of both varieties, and the best response was observed for Aguará 04 variety. Moreover, the increased intensity of irrigation negatively affected the energy balance, reducing the ratio between energy produced and energy used in the production chain. The most significant inputs in the energy intake were fertilizer followed by diesel oil, when irrigation was not used for. When the irrigation technique was used, the most significant inputs, in order of representativeness, were: energy, fertilizer and equipment.