Interações entre aves frugívoras e plantas em um fragmento de mata atlântica de Minas Gerais

We studied the frugivorous birds and their fruiting plants during two years in a forest fragment in Viçosa, Minas Gerais State, Brazil. Our aim was to identify the importance of birds and plants based on an importance index that comprise both the number of interactions and interaction exclusiveness. Twentynine bird species and 25 plant species were recorded. Small birds (< 100 g) comprised 85% of the interactions, and Chiroxiphia caudata reached the largest importance index (0.296), with 12 interactions, being six exclusive. Among plants, the melastome Miconia cinnamomifolia reached the largest importance index (0.277), interacting with 72.4% (21) of the bird species. This study showed that seed dispersal by small birds couldn't be underestimated because they disperse seeds of many plant species, even in pristine forests. Studies like this are also important to list the main food resources to frugivorous birds that could be used in management plans.

Diversidade florística de plantas vasculares no município de Januária, Minas Gerais, Brasil

The vegetation in north Minas Gerais State is poorly known, and for some authors it is the southern limit of natural occurrence for 'carrasco' and 'caatinga' species. Floristic sampling was made in different areas of Januária municipality, Minas Gerais, including physiognomies of 'carrasco' (tree-shrub 'caatinga'), deciduous forest, 'cerrado', floodable field and riparian vegetation ('vereda'), besides calcicolous vegetation. Six-hundred-eight species in 114 families were found, the five most diverse families were Fabaceae (87 species), Asteraceae (35 species), Euphorbiaceae (28 species), Bignoniaceae (25 species), and Malpighiaceae (21 species). The sampled vegetation included a diversity of vegetation forms. The most diverse areas were the 'carrasco' and the deciduous forest (274 species), secondary vegetation along roads and trails, and pastures (160 species), 'cerrado' (105 species), 'vereda' (98 species), and calcicolous vegetation and riparian vegetation (78 species each). Compared to other floristic surveys performed in northeastern Brazil, even considering only the woody component (tree and shrubs with 323 species), these results highlight the floristic and physiognomic diversity of the studied area. © 2005 Instituto de Ciências Biológicas - UFMG.

Bioatividade de plantas medicinais no controle de Sclerotinia isolado de Stevia rebaudiana (Bert.) Bertoni

The microorganism Sclerotinia was isolated from roots of Stevia rebaudiana (Bert.) Bertoni in plantations in the northwest of Parana and submitted to the cultivation in the presence of extracts and vegetable balsams of Tarragon (Artemisia draconculus), Thyme (Thymus vulgaris), Manjerona (Origanum majorona), Mint citrata (Mintpiperita var. citrata), Purple Basil (Ocimum basilicum L.), Andiroba (Carapa guanensis) and Copaíba (Copaifera reticulata Ducke). The first five oils were extracted by steam drags, after the drying of the vegetable in greenhouse with circulation of air at 45°C. The last two were used in natura. A suspension (100ìl) of fungus previously cultivated, was added to each plate. The results show that after 7 days of incubation the thyme oils 10ìl, purple basil 25ìl, manjerona 25ìl, mint citrata 50ìl, tarragon 50ìl were capable to inhibit the growth of Sclerotinia, while the andiroba oil only reached this result with 200ìl. The copaiba balsam, even in the concentration of 500ìl, was unable to inhibit the growth of the microorganism.

Efeitos da dessecação de plantas de soja no potencial fisiológico e sanitário das sementes

The objective of this paper was to verify the ideal moment of application of desiccants on the soybeans crop, to obtain seeds with maximum physiological and sanitary quality. The cultivar IAC-15 was sowed at the experimental area of FE/UNESP - Campus of Ilha Solteira, located in the district of Selvíria, State of Mato Grosso do Sul (20° 22′S, 51° 22′W at approximately 335 m of altitude). The experimental design was a randomized block, with treatments in a factorial scheme of 3×3 and 4×4 (dessicant x application time), in 1996/97 and 1997/98, respectively. The desiccants applied during the season agricultural year 1996/97 were: paraquat, diquat, paraquat+diquat mix at the doses 400; 300; 200+150 e 400 g a.i.ha -1, respectively. In 1997/98 the same desiccants were used, at the same doses, with additional treatment application of ammonium glufosinate at the dose of 400 g a.i.ha -1. The desiccants were applied three times in 1996/97 and four times in 1997/98 with 5 days intervals starting at the R 6 stage. According to the environmental conditions of this research the best desiccation time was when soybean plants had 80% to 90% of pods with yellow and brown coloration and seeds with 45% to 60% of water content. There were no effects of any of the desiccants tested in the physiological and sanitary potential required for commercialization of the seeds.

Plantas do cerrado brasileiro com atividade contra Mycobacterium fortuitum

Mycobacterium fortuitum is a rapidly-growing species of bacteria, ubiquitous in the environment and related to important human mycobacterioses. It has been isolated from blood, abscesses, the endocardium and surgical and traumatic wounds. This mycobacterium is hard to treat, being recognized in the literature as resistant even to the drugs used in the treatment of tuberculosis. The objective of this study was to screen extracts prepared from plants of the Brazilian cerrado (extended savanna-like belt) with known activity against M. fortuitum, employing the Microplate Alamar Blue Assay (MABA) as the analytical method. Out of 26 extracts tested against M. fortuitum, the nonpolar extract of Quassia amara (in methylene dichloride) gave the best result (MIC 62.5μg/ mL), followed by the nonpolar extracts of Syngonanthus macrolepsis, Davilla elliptica and Turnera ulmifolia, with equal MICs of 125μg/ml. The polar extracts (in ethanol and methanol) obtained from the same plants were considered inactive, since the MIC values determined were above 500μg/mL and not significantly different from those of extracts from other plants, without known activity.

Precisão de plantas planialtimétricas em função do posicionamento de pontos em irradiadas de campo

The present experiment aimed to study the influence of point positioning in an irradiated field to produce a planialtimetric plant. A planialtimetric evaluation was carried out in a 14-acre experimental area with well-defined topographic variations. Planialtimetric maps were designed using manual procedures, Datageosis and Topoesalq. Datageosis built all the curves after numerical surface modeling. Topoesalq provided only height reports and the drawing of curves was done manually. The third method was a manual procedure. Because there were planialtimetry representation differences, longitudinal profiles were used in the sites where there was a great divergence among plants. When obtained profiles and plants were compared, it was verified that the one produced by Datageosis represented the relief plant better. Later, only the irradiated field points were evaluated and each point presented positioned readings before and after each relief map variation. The processing through the three methods resulted in significant plants of the local planialtimetry, according to the control profiles. It was concluded that the planning of the field procedure should be suitable to the posterior treatment method of obtained data in order to make a planialtimetric plant to accord to the evaluated local topography.

Comparação de dois métodos de aplicação de fungicidas, irrigação por gotejamento e pulverização convencional no controle do mofo cinzento (Botrytis cinerea Pers.: Fr.) em vasos com plantas de lisianthus (Eustoma grandiflorum (Raf.) Shinn.)

Plan disease control techniques are used through the irrigation water, which reduces the labor and it improves application uniformity with smaller contact of the operator with toxic products, lower environmental impact and lower production cost. In order to control Botrytis cinerea the lisianthus culture, this work aimed to evaluate two fungicide application methods with different treatments. The fungicides were: thiophanate methyl (50 g i.a. L-1), thiophanate methyl + chlorothalonil (50 g i.a. L-1 + 35 g i.a. L-1) and iprodione (50 g i.a. L-1). Number of lesions, number of diseased floral buttons and height of the lisianthus plants were evaluated. It was possible to deduce, that in the growth stage (number of lesions in the plant) as well as in the final stage (number of floral buttons) of the lisianthus culture, the most efficient treatments were 2 (thiophanate methyl + chlorothalonil) and 3 (iprodione). Considering that treatment 2 is a mixture of two fungicides, a systemic and a contact one, independently of application methods, the mixture increased efficiency in relation to treatment 1 (thiophanate methyl). Thus, chemigation was as efficient as spreading technique.

Conhecimento popular sobre plantas medicinais em comunidades rurais de mata atlântica - Itacaré, BA, Brasil

This study's goal was to caryy out an ethnobotanical survey focusing on the knowledge and use of medicinal plants within two rural communities (Marambaia and Camboinha), which are situated in an Environmental Protection Area in Atlantic Forest of Southern Bahia, Brazil. These communities use medicinal plants as an important therapeutic activity, which permits the rural inhabitants to be self-sufficient regarding health care. Data were collected through interviews with 26 families (24% of the total). The medicinal plants collected (98 species) were catalogued, identified and deposited at the Herbarium Rio Clarense (HRCB). They belong to 40 families so that Lamiaceae was the most cited. The majority of these species (78%) are cultivated, usually in backyards by local inhabitants. The leaf is the most common part of the plant used in medicinal preparations. The species with the greatest number of citations were Chenopodium ambrosioides L. and Lippia alba (Mill) N.E. Br. These species are also associated with the highest number of therapeutic uses. Use agreement and diversity index from this survey were compared to other surveys conducted in Brazilian Tropical Forests.

Atividade mutagênica de plantas medicinais

The number of studies of genotoxic activity of medicinal plants has been growing alongside with their increasing therapeutic use and scientific interest in proving their effectiveness for a variety of pharmacological purposes. This reflects the fact that many of the plants used by great numbers of people, in spite of their proven pharmacological value, can also cause harmful changes in the DNA. The risks are greater when alternative treatments are applied in an uncontrolled way, without due attention to correct botanical identification, to the part of the plant that should to be used and to the method of preparation and administration. In this review, aspects of the mutagenic activity of some medicinal plants are discussed.

Alterações morfoanatômicas em plantas de Lithraea molleoides (Vell.) Engl. submetidas ao alagamento

Flooding effects in Lithraea molleoides plants were studied. Young plants were kept under drained and flooded soil over a period of 35 days. For growth and development analyses, the length and diameter of stem and main root and the dry weight of roots, stem, and leaves were measured. For anatomical studies, sections of fresh and fixed roots, stem bases and leaves were made using standard procedures in vegetal anatomy. The stress reduced the dry weight increment of plants without causing the death of roots or the abscission of leaves. In the stem base, flooding induced the hypertrophy of lenticels and the increase of intercellular space and reduction lower starch contents, in the cortex. Plants flooded displayed greater percentage of cortical intercellular space in the secondary roots and lower investment in secretory structure formation in the stem base. It can be suggested that flooding reduced the recourses allocation to growth. These recourses could be used in morphological alterations, such as hypertrophied lenticels and increase of intercellular spaces, that could contribute to plants survival during stress period, probably, due maintenance of aerobic respiration.

Enraizamento de plantas cultivadas in vitro

The adventitious rooting process of in vitro cultured plantlets is a technique that has been employed for the vegetative propagation of a significant number of native and exotic species. Many factors are associated with the rooting stage influencing positive and/or negatively the establishment of micropropagation protocols. The objective of this work was a literature review of the main inherent factors concerning in vitro rooting process including the correlation among others the endogenous and exogenous auxins levels, juvenility, genotype, mineral nutrition, culture medium conditions, addition of growth regulators and other substances as phenolic compounds and active coal besides growth environmental conditions of in vitro cultures. Although the complete elucidation of all processes involved with rooting of in vitro cultured plants has not been achieved so far, a comprehensive study of the main factors that interfere on rooting is fundamental for the establishment of new researches that might contribute for the rooting of economically important plants.

Arranjo espacial de plantas de milho em sistema plantio direto

The interaction of management practices that increases plant density and reduces row spacing by spatial arrangement, if well planned, can be an excellent opportunity for the producers to increase their profitability. The objective of this study was to evaluate the variation effects of plant spatial distribution in two maize hybrids cultivated in a no-tillage system on the production components. The study was conducted in the CECA/UFAL. The treatments consisted of the cultivation of two hybrids of maize, FORT and AGN 30A00, in row spacings of 0.80 and 0.40 m and with plant densities of 60,000 and 70,000 plants ha -1. The statistical design was randomized blocks in a 2 x 2 x 2 factorial scheme, with three replications. From the results obtained, it may be concluded that neither the row spacing reduction nor plant density increase, as isolated practices, do not increase grain yield in the tested cultivars. The association of the reduction in row spacing and increase in plant population resulted in significant gain in grain productivity for the hybrid FORT.

Influência de solos de diferentes texturas no desenvolvimento de plantas de Eucalyptus urograndis submetidas a déficit hídrico

The studies were developed with plants of Eucalyptus urograndis under greenhouse conditions, at Paulista State University (UNESP), Botucatu - SP, from March to July, 2005. The objective was to evaluate hydric stress influence on morphological and physiological characteristics of plants in clayay (1) and medium (2) soil texture. Two water treatment were used: -0.03 and -1.5 MPa minimum soil water potentials (□w). Plants from soil 2 and - 1.5MPa showed 43% reduction on leaf área, 34% on base stem diameter, 54% on aerial vegetal dry matter and plants from soil 1 presented 42.3% reduction on leaf área, 39,5% base stem diameter and 42% dry matter root reduction in relation to -0.03 MPa. The lowest leaf water potential (□f) value was-17.166 MPa on □w = -1.5 MPa and soil 2 and the greatest one on soil 1 and □w = -0.03 MPa., -6.766 MPa. The treatment -0.03MPa showed about 11,3% higher transpiration values than those plants from -1.5MPa. The higher Rs value (2.149 s.cm-1) occurred on plants under -1.5MPa and soil 2. There was significant correlation between Tf and Rs, and the treatmens from medium soil were more sensitive, reaching until 32°C.

Interferěncia da comunidade infestante sobre plantas de Eucalyptus grandis de segundo corte

Currently Brazil is one of the leading paper and pulp producers in the world market, where Sao Paulo State boasts the greatest production. Because of the pulp prices falling in the world market and the low costs of a second coppice rotation, two experiments (started May and December, 2000) were conducted to evaluate the effects of weeds and of weed-free periods (0, 3, 6, 9, 12, 15 and 18 months) on the growth of Eucalyptus grandis second coppice plants. The field trials were set up in a randomized block design with four replicates and the experimental plots consisted of three rows of fve plants. The December weed community was composed mainly of Brachiaria decumbens (Surinam grass) and Panicum maximum (Guinea grass) and the May weed community was composed mainly by B. decumbens and Digitaria insularis (Sour-grass). Weeds had a low negative influence on growth, diameter development and macronutrients content of E. grandis second coppice plants. In both experiments, slight reductions in growth were observed only between the fully weeded and weed-free periods, after 18 months.

Efeito da chuva sobre a ação do herbicida imazapyr no controle de plantas daninhas aquáticas

The aim of this study was to evaluate the influence of different periods of rainfall that occurred after the application of the imazapyr herbicide on the control efficiency of Pistia stratiotes and Eichhornia crassipes. We studied 10 mm rainfall, applied for 5' at different time periods (0h, 2h, 4h, 6h, 8h, 12h, 24h, not simulated rainfall) after the application of imazapyr formulation Arsenal NA, 250 g ai ha -1 (1.0 L cp ha -1). The experiment had completely randomized design with four replications. Plants were evaluated at 7, 14, 21, 28 and 35 days after application (DAA), and the results submitted to analysis of variance by F test and treatment means compared by Tukey's test (p <0. 05). The occurrence of rainfall up to 6 hours after herbicide application, plants of P. stratiotes, negatively affected its efficiency and control; rainfall intervals over 8 hours had no effect in control. The occurrence of rainfall at all time intervals did not affect the control of E. crassipes plants.