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ABSTRACT Tree density is an important aspect in silvopastoral system (SPS) planning, since low luminosity can limit forage perenniality, especially for tropical forages of C4 metabolism. The objective with this study was to verify if an SPS with high tree density accelerates the pasture degradation process and changes the forage chemical composition. The experiment was carried out by comparison of marandu palisade grass [Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster] pasture in two systems: silvopastoral and open pasture. In the SPS, teak (Tectona grandis) was planted with a density of 750 trees ha-1. Evaluations were carried out over three years (2015, 2016 and 2017). SPS shading reduced herbage mass, tiller density and soil cover over the years. In the marandu palisade grass in the SPS there was a greater stem proportion, which favoured lesser potential digestible dry matter in the first year. Even with a higher amount of stem, higher crude protein concentration and minerals were observed in the SPS. Due to the high density of trees, excessive shading accelerated the process of degradation of the pasture, which demonstrates that planning of the spatial arrangement of tree species is crucial.

The objective of this study was to compare the response of Urochloa decumbens cv. Basilisk pastures in monoculture and silvopastoral systems (SPS), and to determine the most suitable pre-defoliation canopy height for managing this species in SPS. Four pre-defoliation canopy heights (20, 30, 40, and 50 cm) were tested for signal grass in SPS, alongside a control treatment involving defoliation at 20 cm in full sun. The experiment was conducted using a randomized block design with four replicates. The forage accumulation rate was higher in monoculture (36.5 kg ha-1 day-1 of DM) compared to the silvopastoral system (22.0 kg ha-1 day-1 of DM), and there was no significant effect of pre-defoliation canopy height within the SPS. The density of tillers in monoculture was comparable to that observed in canopies managed at a height of 50 cm within the SPS. Leaf mass and leaf percentage were maximized at heights of 40 cm and 50 cm, respectively. Neither the cultivation system nor the pre-defoliation canopy heights in the SPS influenced the fiber and protein content. Leaf accumulation and mass were higher in monoculture, but the cultivation system did not affect the chemical composition of the forage. Heights between 40 cm and 50 cm in the SPS should be used to maximize tillering, mass, and leaf percentage of signal grass ‘Basilisk’. The chemical composition of the produced forage did not undergo significant changes, neither between systems nor across pre-defoliation heights.

ABSTRACT Light stress damages the photochemical apparatus and affects seedling growth of forest species. Using potassium silicate (K2SiO3) can mitigate these deleterious effects and contribute to the acclimatization and robustness of seedlings. This study evaluated the effect of K2SiO3 and shading levels on the photochemical and growth of Alibertia edulis (Rich) A. Rich seedlings. The experiment was arranged under three light conditions based on shading levels of 0 % (full sun), 30 %, and 70 %. Four doses of K2SiO3 applied through foliar spray were tested: 0.0, 2.5, 5.0, and 10.0 mL L–1. Cultivation under full sun and under 70 % of shade was stressful for A. edulis, while cultivation under 30 % of shade improved plant growth. Increasing application of K2SiO3 in seedlings under full sun damaged the reaction center, causing lower photochemical yields, but increased the photochemical efficiency of photosystem II under 30 % of shade. Using K2SiO3 contributed to leaf water regulation while applying 10.0 mL L–1 increased chlorophyll indices, leaf area, physiological indices, and the quality of seedlings cultivated under full sun and 30 % of shade. Using 10.0 mL L–1 K2SiO3 mitigated the negative effects of light stress under full sun. It provided high photochemical efficiency, morphology aspects, and Dickson quality index A. edulis seedlings in environments with high or moderate light availability.

ABSTRACT Despite the great economic importance of yerba mate (Ilex paraguariensis A. St.-Hil.), information about clonal plantations and planting conditions of this tree is still scarce. Thus, we evaluated initial field establishment of five clonal yerba mate cultivars, planted at three seasons of the year (summer, autumn, and spring) in a shaded environment, and in the autumn, we also established blocks in a full sunlight environment, to compare both cultivation environments. We evaluated plants at 3, 6, 9, and 12 months after planting, counting the surviving plants, shoots number, and measuring height and canopy diameter. At 12 months we also analyzed the caffeoylquinic acids (CQA) contents in mature leaves from different environments. Plant survival and growth were not affected by planting seasons. Cultivars Aupaba and BRS 409 had the highest survival rates in all seasons evaluated. The shaded environment provided greater survival and growth than full sunlight, also showing higher CQA levels in the leaves. Clonal cultivars Aupaba, BRS 408, and BRS 409 presented higher growth in both environments. The severe drought in the first year may have affected survival; however, growth was considered satisfactory and plants’ initial establishment was better in the shaded environment.

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Studies related to climate change and agricultural value chains have in common the growing concern on conserving water resources. Thus, the concept of the water footprint stands out, which measures the amount of water (in volume) necessary to produce a unit (in mass) of a given product. Among Brazilian agricultural activities, coffee farming emerges as one of the most important, even though the crop is sensitive to potential climatic changes, especially to the increase in temperature and periods of drought. An alternative to mitigate the effects of climate change is shade management, which is common in agroforestry systems. Therefore, the objective of this study was to evaluate the influence of shade management on the water footprint of coffee activity in the region of “Matas de Minas”. The water footprint was calculated for the field and product processing phase. Despite reducing the evapotranspiration of the coffee plant, shade management provided an increase in the water footprint, since it decreased the crop yield. The water footprint data obtained are expressive, with a calculated value of 13,862 m3 t-1 for full sun management and 16,895 m3 t-1 for shade management, in which both are the most recommended for the agricultural sector.

ABSTRACT The objective was to test the response of Urochloa brizantha cv. Marandu in monoculture and in silvopastoral system (SPS), at two distances from the trees, and define the best defoliation height for SPS. Four intermittent defoliation heights (25, 35, 45 and 55cm) and two distances from tree lines (2.5 and 5.0m) were evaluated in the SPS with a control defoliated with 25cm in full sun. The experiment was performed in a randomized block design with 3 replicates in a 4 × 2 + 1 split plot scheme. The control had higher forage accumulation (46.9kg/ha. day) than the SPS (31.1kg/ha. day). The bulk density was also higher in the control (0.89mg/cm³) than in SPS (0.48mg/cm³). The percentage of leaves (78.06%) and leaf/stem ratio (6.04) did not differ among the treatments. In the SPS, there was an increase of 31.07% in forage accumulation from 25 to 55cm. The forage accumulation and bulk density of Urochloa brizantha cv. Marandu in monoculture is greater than in the SPS regardless of the management goal and the distance from trees. The goal of 55cm in the SPS presented greater forage accumulation.

Basella alba L. (Malabar spinach) is a non-conventional food plant (PANC) with high nutritional value and economic potential. Light is a critical factor in plant growth, acting directly on the photosynthetic process. The photoselective meshes combine the physical protection of plants with the selective filtering of solar radiation to promote physiological responses. This work evaluates the growth of B. alba under different light environments. The experiment occurred in a greenhouse at the Center for Agrarian, Environmental and Biological Sciences of the Federal University of Recôncavo da Bahia in a completely randomized design with plots comprising one useful plant and five replications. The plants were grown in three light environments: red ChromatiNet mesh, aluminet-thermo reflective mesh (both with 50% irradiance), and under full sun. The red mesh increased the root dry matter mass and stem diameter. The aluminet mesh increased the average number of leaves by about 50% compared to the plants cultivated under full sun. The results show that the cultivation of B. alba in different light environments promotes morphophysiological changes with positive increments in growth.

This study aims to analyze the incorporation of basalt rock dust to a commercial substrate based on pine bark under two light conditions on initial growth of Monteverdia ilicifolia (Mart. Ex Reissek) Biral seedlings. We evaluated four proportions of rock dust: 0% (control), 10%, 20%, and 30% on plants kept unshaded and under 50% shading for 140 days. The unshaded condition associated with basalt rock dust incorporated to substrate presented the higher seedlings growth. Incorporating rock dust in any proportion to the substrate increased stem diameter and biomass, resulting in a greater Dickson quality index (DQI) in unshaded seedlings. The rock dust in a proportion of 10% showed better results in seedlings growth. Moreover, 20% and 30% of rock dust reduced stem diameter, biomass, and DQI, when compared to 10% of rock dust, possibly due to the substrate physical characteristics. We recommend incorporating 10% of rock dust to the pine bark-based substrate for M. ilicifolia seedlings production in an unshaded environment.

ABSTRACT The Brazilian Northeast region has favorable climatic conditions for the development of floriculture; however, water scarcity and salinization of part of its water sources act as an obstacle to this activity. In this context, the objective was to test the effects of increasing levels of salinity in irrigation water on the quantitative and qualitative responses of ornamental species Euphorbia milii and Zamioculcas zamiifolia, under different light conditions. The study was carried out using an experimental design in randomized blocks, in a split-split-plot scheme, with five replications. The plants were grown in 7 L pots, undergoing an initial period of acclimatization for 15 days with non-saline water so that their establishment would not be compromised; after this period, the plants were subjected to increasing levels of salinity in the irrigation water (0.5; 2.0; 3.5; and 5.0 dS m-1) under four light intensities (full sun, 30%, 50% and 70% shading) for 60 days. The variables analyzed were plant height, stem diameter, belowground and shoot biomass, salinity tolerance and qualitative analysis. Shading had a greater impact on the qualitative variables of the plants than on the salinity tolerance based on quantitative variables. The environment with 30% shading is the most favorable for the cultivation of E. milii when using water with low to moderate salinity. Shading reduces direct radiation damage to Z. zamiifolia leaves and improves the visual quality of this species under high salinity.

Abstract The objective of this work was to evaluate the effect of pre-harvest spraying with aminoethoxyvinylglycine (AVG) and ethephon on fruit maturation of 'Baigent' apple (Malus domestica) trees grown under black anti-hail nets. The treatments were: control; 125 mg L-1 AVG, sprayed 30 days before anticipated harvest time (DBAH); 120 mg L-1 ethephon 7 DBAH; 62.5 mg L-1 + 62.5 mg L-1 AVG 30 and 20 DBAH; and 62.5 mg L-1 + 62.5 mg L-1 AVG 30 and 20 DBAH + 120 mg L-1 ethephon 7 DBAH. Fruit were harvested in the commercial harvest of the control treatment (harvest 1) and 14 days later (harvest 2). Yellowing and loss of firmness were delayed by the treatments with AVG and accelerated by that with ethephon. AVG application in a single rate of 125 mg L-1 30 DBAH or in two split rates of 62.5 mg L-1 30 and 20 DBAH delays fruit maturation. The pre-harvest application of AVG in a single rate reduces the red color of the fruits, which is not affected by application in split rates, combined or not with ethephon, regardless of the date of harvest.

ABSTRACT Weeds are one of the ecological factors that directly affect agricultural costs. Thus, understanding the emergence and development of these species is essential for the decision-making on weed control strategies. This study aims to evaluate the effect of different sowing depths and luminous intensities under field conditions on the emergence and development of the Acanthospermum australe (Loefl.) Kuntze and Ipomoea grandifolia (Dammer) O’Donell. Each species constituted one experiment, and the completely randomized design with four repetitions was adopted. The treatments were arranged in a 6 x 4 factorial scheme, with six sowing depths (0.5; 1.0; 2.0; 4.0; 8.0; and 12.0 cm) associated with four luminous intensities (100%, 70%, 50%, and 30% sunlight) obtained using shade cloths. The emergence of seedlings was evaluated daily to obtain the emergence and the emergence speed index. Plant height(length), the period until flower induction, and the dry matter of plants during flowering were also analyzed. A. australe and I. grandifolia emerge under the luminous intensities of 100, 70, 50, and 30% of solar radiation and in sowings depths up to 12.0 cm. Nevertheless, A. australe is the only one affected by luminous intensity, sowing depth, and the interaction between both factors in all the analyzes conducted. Luminous intensity reduction leads to lower development of I. grandifolia.

The use of shading screen in vegetable crops sensitive to the radiation excess, associated with the effective water use via irrigation, allows for yield gains. This study aimed to evaluate the yield characteristics of cherry tomato cultivated with and without shading screen and different irrigation levels. A randomized block design was used, in a 4 x 2 factorial arrangement, with four irrigation levels (140 %, 160 %, 180 % and 200 % of the reference evapotranspiration - ETo) and two cherry tomato hybrids (Wanda and Dolcetto). The irrigation level corresponding to 200 % of the ETo provided the highest values for number of flowers and clusters formed, number of fruits per plant and fruit diameter. The Wanda hybrid was more fruitful, with a higher emission of clusters, while Dolcetto was more floriferous. The use of shade screen for cultivating cherry tomato provides an increase in the yield characteristics, if compared to the cultivation in open areas.

ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.

Copyright of Revista Agrotecnologia is the property of Universidade Estadual de Goias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT: An experiment was conducted to investigate the effects of different shading regimes [i.e., 60% (heavy), 30% (moderate), and 0% (control)] on 25 traits associated with the morphological features, photosynthetic gas exchange and agronomic characteristics of winged bean (Psophocarpus tetragonolobus), an underutilized protein-rich legume from the tropics. Collectively, 80% of the studied variables displayed significant differences (P

Objetivou-se neste trabalho descrever morfologicamente o pirênio e caracterizar os estágios morfológicos da plântula de Oenocarpus bataua durante a germinação e emergência e verificar o efeito do substrato e ambiente na emergência de pirênios de Oenocarpus bataua. Foram utilizados frutos obtidos de mistura de matrizes. Os frutos maduros foram submetidos à extração do epicarpo e mesocarpo. No primeiro ensaio, foi realizada biometria em 200 pirênios e semeados em vermiculita para caracterização morfológica das plântulas. No segundo ensaio, foi testada a influência de diferentes substratos (vermiculita, Plantmax, solo natural e areia) e condições de luz (a pleno sol e em ambiente de viveiro), sobre a emergência das plântulas. As variáveis analisadas foram: porcentagem de emergência e tempo médio de emergência. O pirênio é ovalado, o endocarpo é formado por fibras com coloração amarelo-clara e marrom, estando aderidas ao tegumento, possui único poro germinativo. A germinação é adjacente ligulada e hipógea. A completa expansão da primeira folha bífida dá-se aos 95 dias. Os substratos mais adequados para a emergência de plântulas de Oenocarpus bataua são vermiculita, areia e Plantmax.This work aimed to describe morphologically the pyrenes and characterize morphological stages of the Oenocarpus bataua seedling during germination and emergence, and to verify the substrate and environment effects in the emergence of Oenocarpus bataua Seeds were used obtained from mixing matrix. The ripe fruit were submitted to the extraction of epicarp and mesocarp. In the first experiment was conducted biometrics in 200 seeds and sown in vermiculite for morphological characterization of the seedlings. In the second experiment the influence of different substrates (vermiculite, Plantmax, natural soil and sand) and light conditions (full sun and nursery environment) on the emergence of seedlings were tested. The analyzed variables were: percentage of emergency and mean time of emergency. The pyrene is oval, the endocarp is formed by fibers with light yellow and brown color being adhered to the integument, it has only germinative pore. The germination is adjacent ligated and hypogeous. The complete expansion of the first bifid leaf occurs at 95 days. The most suitable substrates for emergence of Oenocarpus bataua seedlings are vermiculite, sand and Plantmax.

ABSTRACT This research aimed to assess the climatization configuration in a holding pen for dairy cattle considering physiological responses of animals and thermal comfort indexes. Experimental design consisted of 16 cows in a Latin square design containing four groups of four animals (G1, G2, G3 and G4) and four periods (P1, P2, P3 and P4), in which four environments were used as treatments: EXT – external environment (control); SHA – shading with polypropylene mesh, 80% light interception; S+S – shading and water sprinkling; and S+S+V – shading, sprinkling and ventilation. Dry and wet bulb temperature, black globe temperature, wind speed and humidity were recorded during the climatization process, between October 13 and December 7. Subsequently, temperature-humidity index (THI), black globe temperature and humidity index (BGTHI), radiant heat load (RHL) and heat load index (HLI) were calculated. After climatization, respiratory rate (RR), surface temperature (ST), and rectal temperature (RT) were recorded. Animals submitted to EXT presented physiological responses that indicated heat stress. The best physiological response was found in S+S+V, which reduced RR by 58.6% when compared to the other environments.

ABSTRACT: The repetitive use of glyphosate in the control of weeds in eucalyptus plantations has selected tolerant species such as Commelina benghalensis. Therefore, the use of herbicides of other mechanisms of action, such as saflufenacil, in rotation or combination with glyphosate, is necessary to reduce damages caused by C. benghalensis, whose sensitivity to herbicides can be influenced by the shading caused by the eucalyptus crop. This study aimed to assess the efficiency of saflufenacil in the management of C. benghalensis at different shading levels. Three experiments were carried out regarding a certain shading level (cultivation environment with 0, 40, and 55% shade). The experimental design was a randomized block design with five herbicide doses (0, 24.5, 49, 73.5, and 98 g ha-1 of saflufenacil) and four replications. At 28 days after herbicide application, the percentage of control and shoot dry matter were assessed, as well as the biomass allocation to leaves, stems, and roots of C. benghalensis. Plants cultivated at 0% shade presented a higher dry matter accumulation and a better distribution of biomass in leaves, stem, and roots, contributing with the increased tolerance to saflufenacil and not being controlled with effectiveness under the assessed doses. As shading was increased, plants of C. benghalensis allocated most of their biomass to the shoot, especially leaves, reducing their reserve structures and increasing the contact area with the herbicide, making them more susceptible to saflufenacil.

The different shading levels, as well as the quality and quantity of light can influence the development and formation of seedlings of forest species. The objective of this study was to evaluate different types of shading, aiming to obtain Tabebuia serratifolia seedlings with higher quality and better yield, when compared to full sun treatment. The treatments used were: full sun, 50% black polyethylene shading screen, 50% black polyethylene + 100% polyester fibers, transparent plastic and 100% polyester fibers. The plots were organized in a completely randomized design, with the treatments represented by environments, containing 6 replications, 8 plots and 144 seeds per treatment. The parameter analyzed up to 30 days was the emergence percentage, at 60 and 100 days, height and diameter were collected, while dry matter weight of root, shoot, total, dry matter weight of root/shoot ratio and Dickson quality index were evaluated with the end of the experiment. For emergence percentage, base diameter, root dry biomass and total dry biomass, there was no significant difference in the studied treatments. The time spent in the environments interfered with the emergence and development of Tabebuia serratifolia species, where the best environment was the one with the lowest light intensity, that is, shading with plastic + 100% polyester fibers. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Applied Technology for Agricultural Science / Revista Brasileira de Tecnologia Aplicada nas Ciências Agrárias is the property of Brazilian Journal of Applied Technology for Agricultural Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed the automatic identification of trees in circular sample units of 200, 300 and 400 m² in stands of Eucalyptus spp., using TLS (Terrestrial Laser Scanning) in Mato Grosso do Sul State, Brazil. Three planting ages were tested: 2 years-old-plantation, considering trees with natural pruning (E. urophylla -200 m²) and without natural pruning (E. grandis - 300 m²), and trees with 4.5 and with 5.5 years-old without pruning (hibrid E. urophylla x E. grandis - 400 m²). Field laser scanning was performed with Trimble TX5 equipment. This approach was based on a cut of pointcloud at 1.3 m above ground level (DBH) and the developing the algorithm 2D slice. It was possible to detect 98.3, 98 and 93.9% of trees for samples units of 200, 300 and 400 m², respectively. These identifications were influenced by the spatial distribution of trees because of the shading of trees further from the equipment. This simple scan should be applied only for small sample units. The error detections in areas greater than 200 m², may influence negatively the dendrometric estimations. [ABSTRACT FROM AUTHOR]

ABSTRACT The objective of this study was to evaluate the effect of light availability and salt stress on the growth and quality of hazel sterculia seedlings. The experiment was conducted with two light conditions – full sun (L1), and 50% shading (L2) – and five salinity levels in the irrigation water – 1.0 (S1), 2.2 (S2), 3.2 (S3), 4.2 (S4), and 5.1 (S5) dS m-1. The environment with 50% shading was the most suitable to produce hazel sterculia seedlings, even under high salinity (5.1 dS m-1). Increasing salinity negatively affects the growth and quality of hazel sterculia seedlings. Therefore, controlling sunlight availability and irrigation water saline conditions increases rooting potential and seedling survival in the field.

ABSTRACT The objective of this study was to evaluate the germination potential of Matayba elaeagnoides seeds, identifying the best substrate for laboratory analysis and to determine seedling emergence and growth under different shade levels in the nursery. Different substrates (paper roll, between and on blotting paper, and on sand or vermiculite) were evaluated in the germination test and different shade levels (0, 30, 50 and 75%) were tested in the nursery. No differences were found between the substrates for seed germination, however, the highest germination percentage was observed when using paper roll (70%). The 30, 50 and 75% shading intensities positively influenced Matayba elaegnoides seedling emergence, however, the best performance in nursery growth was observed under 75% shade presenting seedlings with better standard and quality.

Phytosociological surveys are very important when identifying an invasive community in order to carry out more suitable weed management. The aim of this study therefore, was to identify the main species of weeds in banana plantations, both newly-planted and under production, in the northern region of the State of Minas Gerais, Brazil. For the phytosociological study and characterisation of the weed community, two areas of ‘Prata’ bananas, both of 10 hectares, were evaluated using the method of inventory squares, which were randomly thrown along a zigzag path. The following phytosociological variables were evaluated: frequency, relative frequency, density, relative density, abundance, relative abundance, importance value index, relativeimportance value index and similarity index. In the newly-planted area, 17 species were found, divided into 15 genera and ten families, with the Fabaceae and Poaceae families being prominent. The species with the highest importance indices were: Sida spp. (62.38), Galinsoga parviflora (32.36), Amaranthus hybridus (24.93) and Ipomoea hederifolia (19.61). In the area under production, 12 species, 12 genera and ten families were found, with the Asteraceae family being prominent. The species with the highest relative-importance value indices were: Commelina benghalensis (39.19), Emilia fosbergii (34.42) and Amaranthus hybridus (32.96). Between the two areas, there was a difference in the mean values for density, and for the number of plants with C4 metabolism; five in the newly-planted area, and three in the area under production. The Similarity Index between the two areas was 48.27%, with seven species common to both areas. = O levantamento fitossociológico é muito importante para conhecer a comunidade infestante e, com isso, realizar de forma mais adequada o manejo das plantas daninhas. Objetiva-se com este trabalho identificar as principais espécies de plantas daninhas em áreas de bananicultura recém-implantadas e em produção na região do norte de Minas Gerais. Para caracterização e estudo fitossociológico da comunidade infestante, avaliaram-se duas áreas de banana-prata, ambas com 10 hectares, nas quais se utilizou o método do quadrado inventário, lançado aleatoriamente por meio de um caminhamento em ziguezague. Avaliaram-se as seguintes variáveis fitossociológicas: frequência, frequência relativa, densidade, densidade relativa, abundância, abundância relativa, índice de valor de importância, índice de valor de importância relativa e índice de similaridade. Na área recém-implantada foram encontradas 17 espécies, divididas em 15 gêneros e dez famílias, destacando-se, dentre essas, as famílias Fabaceae e Poaceae. As espécies com maiores índices de importância foram: Sida spp. (62,38), Galinsoga parviflora (32,36), Amaranthus hybridus (24,93) e Ipomoea hederifolia (19,61). No bananal em produção, encontraram-se 12 espécies, 12 gêneros e dez famílias, com destaque para a família Asteraceae. As espécies que apresentaram maiores índices de valor de importância relativa foram: Commelina benghalensis (39,19), Emilia fosbergii (34,42) e Amaranthus hybridus (32,96). Entre as duas áreas houve diferença nas médias de densidade e nos números de plantas com metabolismo C4; na área recém-implantada foram cinco e na área em produção foram três. O Índice de Similaridade entre as duas áreas foi de 48,27%, sendo sete espécies comuns às duas áreas.

Growth, development and fruit quality blueberry (Vaccinium corymbosum L.) variety Brigitta under different shade nets were evaluated. Assays were performed in plants 7 years in a commercial orchard Collipulli, Araucanía Region, Chile. Treatments were a control without shading and four types of screens: a red 40% and 18% shade; aluminized mesh with 40% shade and a black mesh 35% shade. In fruits shade of red mesh 40% greater equatorial and polar diameter were observed and three weeks later harvested the fruits of treatment without mesh. In growing shade 40% aluminized mesh phenological stages extension lag and the maximum weekly production two weeks over control was observed. The highest yields were observed in plants of treatment and control shade of red mesh 40%, with 11008 kg ha-1 and 10461 kg ha-1, respectively, while the lowest was in red mesh 18% with 9668 kg ha-1. The fruits grown under shade of red mesh 18% showed the highest number of fruits per plant with 1806 berries per plant, fruit weight less than 1.69 g with the strongest with 3.76 N mm-1 module deformability. Therefore, the largest weight berry fruits observed in non-mesh screen and 40% red shading, together with the increased size and performance.

Bauhinia variegata and B. variegata var. candida, commonly known as orchid trees, are small sized trees widely used for urban forestry and landscaping. Adult plants grow under full sun; in Brazil, however, seedlings are generally cultivated in commercial nurseries under natural half-shading. The objective of this study was to evaluate the influence of different colored shade nets and light conditions on the initial growth of B. variegata and B. variegata var. candida. The influence of six light conditions (red net with 50% shading; blue net with 50% shading; black net with 70% shading; black net with 50% shading; black net with 30% shading; and full sun) on the initial growth of B. variegata and B. variegata var. candida were evaluated along 160 days, and growth relationships were calculated. Seedlings showed more efficiency on the use of photoassimilated compounds when grown under full sun. Such condition is the most appropriate for seedling production of B. variegata and B. variegata var. candida, contradicting what has been performed in practice.

The objective of this study was to analyze the initial development of banana tree seedlings under different growing environments. The experiment was installed and conducted in the Santa Marcia farm, in the municipality of Nova Xavantina-MT. Four banana varieties were evaluated: BRS Princesa, Grande Naine, Prata Anã and BRS Platina, which were conditioned in four growing environments: full sun, 30% shade, 50% shade, and thermo-reflective screen (aluminet). The experimental design was a randomized block design with factorial arrangement (4 cultivation environments and 4 varieties). The evaluated characteristics were: plant height (AP), pseudocaule diameter (DP), leaf number (NF), shoot dry matter (MSPA), root dry matter (MSR), total dry matter relation height and diameter of the pseudocaule (H / D). The seedlings produced under the 50% and Aluminet shading screens obtained better results for the evaluated characteristics, except for root length (CZ) and pseudocaule diameter (DC), not statistically different for the cultivation and variety environment interaction. [ABSTRACT FROM AUTHOR]

RESUMO O objetivo do trabalho foi avaliar a capacidade de brotação de cepas de teca sob regime de talhadia composta. O experimento foi implantado nos espaçamentos 3,0 × 2,0 m e 3,0 × 3,0 m. Aos 8 anos de idade, o experimento foi desbastado sistematicamente, em 50%. Após o desbaste, foi avaliado o potencial de brotação das cepas das árvores desbastadas. O delineamento experimental utilizado foi o de blocos ao acaso, com 2 tratamentos e 5 repetições. Os tratamentos foram T1 = brotação conduzida sob regime de talhadia composta no espaçamento 3,0 × 4,0 m e T2 = brotação conduzida sob regime de talhadia composta no espaçamento 3,0 × 6,0 m. A teca apresentou capacidade de brotação de cepas sob regime de talhadia composta até o período avaliado de 12 anos de idade, para ambos tratamentos.

Luminosity influences seed emergence in the initial development of papaya plants, being necessary the identification of the ideal irradiance level for plantule establishment and formation of vigorous seedlings. This study aimed to evaluate the seed emergence and seedlings vigor of four papaya genotypes, under different irradiance levels. Carica papaya L. seeds, from the Caliman 01 hybrid, Golden THB, triple hybrid and JS12 x Waimanalo hybrid genotypes, were evaluated under four irradiance levels (60 µmol m-2 s-1, 130 µmol m-2 s-1, 580 µmol m-2 s-1 and 1,200 µmol m-2 s-1). A completely randomized design, in a 4x4 split-plot scheme, with four replications, was used. The emergence percentage and speed index were evaluated. The seedlings were measured at 45 and 120 days after sowing (DAS), concerning root and shoot length and dry matter, being calculated the root/shoot ratio and absolute growth rate at 120 DAS. The full sun affected emergence, while the low irradiance affected seedling growth. The intermediate irradiance (130 µmol m-2 s-1 and 580 µmol m-2 s-1) was more suitable to the development of papaya seedlings up to 120 DAS. The Golden THB genotype was more sensitive to high irradiance, while the Caliman 01 and JS12 x Waimanalo hybrids tolerated the full sun condition.

Sweet pepper is one of the ten most consumed vegetables in world. Although it develops better under protected environment, the cultivation in tropical countries is practiced in open field due greenhouse structure higher costs. Unfortunately, such practice has compromised the crop to reach either best yield or fruit quality. Since production and cost are the most important criteria for agricultural production, we aimed to evaluate reflective aluminized polypropylene shading net influence on sweet pepper (Capsicum annuum L.) growth and production as intermediary alternative for low/middle income producers from Brazilian tropical regions. Sweet pepper Magali R hybrid was cultivated in two environments: FC - field conditions (control) and RS - reflective shading net with 40% shading rate. RS caused reductions in incident solar radiation (SR) and photosynthetically active radiation (PAR) on the amount of 46.3% and 48.3%, respectively. There were no significant changes in temperature and relative humidity recorded for the two environments. In addition, RS allowed best use efficiency of photosynthetically active radiation since it promoted higher values of plant height, leaf number and area index than those reached on FC on the amount of 29%, 22% and 80 %, respectively. Similarly, plants grown under RS showed higher yield and marketable fruits and promoted less loses by sunscald.

The study was carried out with the aim to evaluate the effect of different special arrangements in forage yield, nutritive value and structure of the understory of signalgrass (Brachiaria decumbens) in silvipastoral system with different regrowth times. The design was in complete randomized block with tree replicates in a factorial scheme with split-plots 2 × 2 × 5 consisting two spatial arrangements [Double lines 9 × (2 × 2m) and simple lines (9 × 2m)] in two sampling places (in the middle of the intercropping and under the three canopy) in the plot and five regrowth times (35, 42, 49, 56 e 63 days) in the split-plot. It was used a silvipastoral system established since June, 2008 in degraded pasture with signalgrass predominance. The pasture was homogenized by grazing at 15 cm from the soil level. Were evaluated the dry matter yield leaf:stem ratio, light interception and leaf area index. In addition were evaluated the nutritive value characteristics dry matter content, neutral and acid detergent fiber, crude protein and lignin. The photosynthetic active radiation was monitored. The use of simple or double lines did not influence the leaf area index, light interception and dry mass yield. The leaf:stem ratio was influenced by the sampling place only in the double line arrangement. The neutral detergent fiber was substantially high in the double line arrangement. Therefore, the use of double lines reduces the photosynthetic active radiation amount incident in the understory, but does not reduce the forage yield in relation to simple line arrangements. These results indicate the use of double lines arrangement may allow the harvest of more threes without reduce the pasture production.

The Brazilian agricultural sector stands out as an activity, which besides being fundamental to the economy (trade surplus) is also extremely important to the economic, social and environmental situation. The Gross Domestic Product (GDP) of Brazil came in 2010 at R $ 3.675 trillion, and this value agriculture accounts for 6.5% (R $ 180.80 billion) (IBGE, 2011), thus underscoring the sector's importance to the development of Brazil. Thus, the purpose of this review is to discuss the use of various forms of Integrated Crop-Livestock-Forest (ILPF) for Brazilian agriculture as a way to ensure the prominence and competitiveness of the sector. The Crop-Livestock Integration-Forest (ILPF) is a system that, in addition to adapting the existing agricultural activities practiced by Brazilian farmers, the templates related to environmental issues, especially in the neutralization of the gases emitted by livestock and agriculture to help accelerate the process of global warming may also increase the profitability of agriculture and settle in the field, reducing the rural exodus. However, there is need for increased research related to ILPF system, aiming at harmonization and maximum production.

Arborization can benefit coffee plantations by reducing the wind speed and temperature variation in the crop. It is also possible that the incident radiation can affect the weed populations and reduce the need for their control. This study aimed at assessing the weeds population and distribution, in arabica coffee intercropped with three macadamia cultivars, six years after planting, in Dois Córregos, São Paulo State, Brazil. Treatments consisted of a 3x3+1 factorial scheme, i.e., coffee intercropped with three macadamia cultivars (HAES 816, IAC 4-20 and IAC 9-20) and three sampling positions of weeds in the intercropping (in the macadamia tree canopy projection, among the macadamia tree canopies projections and in the single rows), plus an additional treatment (sole coffee). The weeds incidence and control, as well as their phytosociological characterization, were evaluated. For coffee intercropped with macadamia, the weeds occurrence and number of species were smaller than for sole coffee. For the projection in the canopy and among canopies of macadamia trees, there was an average decrease of 82% in the occurrence of weeds, in comparison with the sole coffee. The IAC 9-20 cultivar was more efficient in reducing the occurrence of weeds, when intercropped with coffee, for presenting a taller canopy, with a larger diameter.

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The seedling utilization the natural regeneration is an important technique used with species with limitations for its germination. This word it was made aiming to test transplantings methods for use in seedling of natural regeneration of the Cordia trichotoma. The seedlings were removed the sub-canopy and their leaf area it was reduced with the pruning shear (0, 50 and 100%) and then placed in the plastic bags in three different incidences of luminosities (70, 50 and 30%). The growth in total height and stem diameter was measured after 150 days. The data were analyzed in a bifactorial scheme and by the average test at 5% probability in statistical software R. There was not interaction between factors shading and leaf cutting. The stem diameter did not differ between treatments. Even without differences between treatments, the highest heigth were found with 50% shading and 50% the reduction in leaf area. These results are related with the ecology and physiology of the specie, and comes to contribute to the seedlings production process, can be a viable technique to be applied in this and other forest species. [ABSTRACT FROM AUTHOR]

O presente trabalho teve como objetivo avaliar parâmetros fisiológicos de mudas de copaíba produzidas sob o efeito de diferentes níveis de sombreamento e tipos de substratos. O experimento teve a duração de 130 dias e foi conduzido em blocos casualizados no esquema fatorial 5x4, com cinco substratos: Bioplant®; 70% vermiculita + 30% casca de arroz carbonizada; 40% vermiculita + 30% casca de arroz carbonizada + 30% fibra de coco; 50% vermiculita + 30% casca de arroz carbonizada + 20% areia; 70% vermiculita + 15% casca de arroz carbonizada + 15% vermicomposto de resíduo de indústria têxtil; quatro níveis de sombreamento (100, 70, 50 e 30% do pleno sol) e três repetições. O nível de sombreamento de 50% em relação ao pleno sol possibilitou a produção de mudas de copaíba com maiores teores de clorofila b e clorofila total, além de proporcionar os menores valores de transpiração diária e ao longo do dia das plantas. A área foliar, os teores de clorofila e a transpiração das mudas de copaíba independem do tipo de substrato, podendo ser produzidas em qualquer um dos meios de crescimento avaliados.This research aimed to evaluate physiological parameters of seedlings of copaiba produced under the effect of different shading levels and types of substrates. The experiment lasted 130 days and was conducted in randomized blocks in factorial scheme 5x4 with five substrates: Bioplant®, 70% vermiculite + 30% rice hulls, 40% vermiculite + 30% rice charred hulls + 30% fiber coconut, 50% vermiculite + 30% rice charred hulls + 20% sand, 70% vermiculite + 15% rice charred hulls + 15% vermicompost residue of textile industry; four shading levels (100, 70, 50 and 30% full sun) and three replications. The shade level of 50% compared to full sun, enabled the production of seedlings of Copaiba with higher concentrations of chlorophyll b and total chlorophyll, and provided the lowest daily transpiration throughout the day and the plants. The leaf area, chlorophyll content and transpiration of seedlings of Copaiba independent of the substrate and can be produced in any of the growth media evaluated.

The integration of renewable energy sources into greenhouse crop production in southeastern Spain could provide extra income for growers. Wind energy could be captured by small to medium-sized wind turbines, gas could be produced from biomass, and solar energy could be gathered by solar panels. The aim of this study was to examine the effect of flexible solar panels, mounted on top of a greenhouse for electricity production, on yield and fruit quality of tomatoes (Solanum lycopersycum L., cv Daniela). This study was undertaken in a commercial raspa y amagado greenhouse, typical of the Almería region (Spain). Tomato plantlets were planted at a density of 0.75 plants m-2. The flexible solar panels were mounted on two parts of the roof in different arrangements (T1 and T2), each blacking out 9.8 % of its surface area. A control area (T0 arrangement) was fitted with no panels. No difference was found in terms of total or marketable production under these three arrangements, although fruit mean mass and maximum diameter of T0 were significantly greater than T1 and T2. Fruit in T0 matured earlier with more intense color compared with those in T1 and T2. However, these differences had no effect on price as the tomatoes produced under three conditions fell into the same commercial class (G class; diameter 67-81 mm). Solar panels covering 9.8 % roof area of the greenhouse did not affect yield and price of tomatoes despite of their negative effect on fruit size and color.

A pitaya é uma cactácea de sub-bosque, originária de florestas tropicais do México e das Américas Central e do Sul, pouco estudada no Brasil, principalmente quanto à sua resposta à intensidade luminosa e adubação. Nesse sentido, realizou-se um experimento objetivando avaliar crescimento e desenvolvimento inicial da pitaya em função da intensidade luminosa e adubação orgânica. O delineamento experimental adotado foi em blocos casualizados, com tratamentos distribuídos em esquema fatorial 5 x 3, referentes, respectivamente, aos níveis de adubação orgânica (0; 5; 10; 20 e 30 L de esterco bovino cova-1) e aos percentuais de luz (0; 50 e 75% de sombreamento), com quatro repetições. Foram avaliados semanalmente diâmetro do cladódio (mm), altura de estacas (cm) e comprimento do ramo secundário (cm); ao final do experimento, massa fresca da parte aérea e massas secas de raiz e parte aérea (g), sendo que para as variáveis mensuradas, semanalmente, foram calculados os respectivos incrementos percentuais semanais. Segundo os resultados do presente trabalho, no cultivo da pitaya, é necessário o uso de cobertura contra a incidência direta dos raios solares, onde as estruturas com 50% ou 75% de luminosidade podem ser usadas. O fornecimento de 20 L cova-1 de esterco bovino pode ser adotado como quantitativo no preparo de covas de pitaya, nas condições de clima e solo de Bom Jesus-PI.Pitaya is a hemiepiphytic cactus native to tropical rainforests of Mexico and Central and South America little studied in Brazil especially in relation to light intensity and fertilizing. In this way, an experiment was realized in 2007 aiming to evaluate the initial growth and development as a function of light intensity and organic fertilizing. A complete randomized blocks design was adopted with treatments distributed in a factorial arrangement 5 x 3 referring respectively to organic fertilizing levels (0, 5, 10, 20 e 30 L of bovine manure plant-1) and light percentage (0, 50 e 75% of shade), with four repetitions. Stem diameter, plant height and length of the secondary shoot were evaluated weekly, instead of shoot and root dry mass and shoot fresh mass were determined at the end of the experiment. For week variables, the respective week increases were measured. For pitaya cultivation it's necessary a covering system with nets and those with 50% or 75% of light intensity should be used. The dose of 20 L plant-1 of bovine manure could be adopted as a quantitative for preparation of pitaya caves under soil and climate conditions of Bom Jesus, Piaui State, Brazil.

O estudo foi realizado com o objetivo de avaliar a produção forrageira e o desempenho de bovinos de corte pastejando sub-bosque de um sistema silvipastoril com eucalipto, adubado com fertilizante nitrogenado e duas ofertas de forragem. Os tratamentos consistiram de três doses de fertilizante nitrogenado (0, 75 e 150 kg ha-1 de N, na forma de ureia), e duas ofertas de forragem (10 e 15% PV). O estudo foi conduzido sob delineamento inteiramente casualizado, com quatro repetições e três períodos de avaliação. Foi observado aumento no ganho de peso, apenas no primeiro período de avaliação, à medida que se elevaram as doses de fertilizante nitrogenado. A variação na oferta de forragem não influenciou os ganhos médios individuais. O ganho por unidade de área aumentou à medida que foram adicionadas doses crescentes de fertilizante nitrogenado. A oferta de forragem de 15% é mais adequada quando se utilizam menores doses de nitrogênio na pastagem. Para doses mais elevadas, a intensificação da utilização resulta em maiores ganhos por unidade de área. A fertilização do sub-bosque é eficiente e necessária para a intensificação do uso de sistemas integrados eucalipto-pastagem.The objective of this study was to evaluate forage yield and performance of beef cattle grazing understory of a silvopastoral system with eucalyptus, fertilized with nitrogen and two forage offers. Treatments consisted of three doses of nitrogen fertilizer (0, 75 and 150 kg.ha-1N as urea) and two forage offers (10 and 15% of BW). The study was carried out in a complete randomized design with four replications and three evaluation periods. It was observed an increment in weight gain only the first period of evaluation as doses of nitrogen fertilizer were increased. Variation on forage offer did not influence individual average gains. Values of gain per area unit increased as increasing doses of nitrogen fertilizer were added. Forage offer of 15% is more properly when lower doses of N were used in pastures. For higher doses, intensification of use results in greater gains per area unit. Understory fertilization is efficient and necessary for intensification of the use of eucalyptus-pasture integrated systems.

Objetivou-se, com a realização da pesquisa, avaliar modificações fisiológicas e anatômicas em plantas de melissa, cultivadas sob malhas termorrefletoras (Aluminet®), em diferentes níveis de sombreamento, visando conhecer a plasticidade fenotípica em resposta de adaptação a diferentes quantidades de luz. Os tratamentos foram caracterizados por plantas submetidas a pleno sol e a 20 e 60% de intensidade luminosa, e arranjados conforme o delineamento inteiramente casualizado (DIC). As quantificações de clorofila foram feitas em quatro repetições, as medições das epidermes e parênquimas foram repetidas 15 vezes e utilizou-se 10 repetições para as avaliações das características de cloroplastos e grãos de amido destes. Plantas submetidas a 20% de intensidade luminosa apresentaram maior quantidade de clorofila a e, portanto, maior razão clorofila a/b. Comparativamente, as folhas de melissa a pleno sol e a 60% de luz apresentaram células da epiderme adaxial mais espessas, mas as células da epiderme abaxial mostraram características encontradas em folhas de sombra, ou seja, mais finas. Quanto maior a intensidade luminosa, maior o número de cloroplastos, porém, a pleno sol mostraram-se mais finos e com menor área. Os grãos de amido de plantas cultivadas sob ambientes sombreados tiveram maior área e ocuparam maior parte nos cloroplastos de plantas a 60% de intensidade luminosa. Assim, plantas de melissa, quando submetidas ao sombreamento, tiveram plasticidade fenotípica.The aim of this study was to evaluate physiological and anatomical modifications in lemon balm plants, cultivated under thermo-reflector nets (Aluminet®) at different levels of shading, in order to understand the phenotypic plasticity in adaptation response to different light quantities. The treatments were characterized by plants subjected to full sun and 20 and 60% of luminous intensity, and arranged in completely randomized design (CRD). The quantifications of chlorophylls were done in four replicates, the measurements of epidermis and parenchymas were repeated 15 times and 10 replicates were used to evaluate characteristics of chloroplasts and their starch grains. Plants subjected to 20% of luminous intensity showed higher quantity of chlorophyll a and, therefore, higher chlorophyll a/b ratio. Lemon balm leaves under full sun and 60% of light showed thicker adaxial epidermis cells, but the abaxial epidermis cells showed characteristics found in shaded leaves, i.e., they were slender. The higher the light intensity, the larger the number of chloroplasts; however, under full sun, they were slender and had smaller area. The starch grains of leaves grown under shaded environments showed larger area and, at 60% of luminous intensity, occupied the largest part of chloroplasts. Thus, lemon balm plants, subjected to shading conditions, showed phenotypic plasticity.

Objetivou-se determinar os possíveis efeitos da restrição de luminosidade, obtida com distintas densidades de árvores de Pinnus taeda, sobre a produção e qualidade de: aveia-preta (Avena strigosa Schreb) cv. Comum, aveia-branca (Avena sativa L.) cv. Fapa 2, azevém (Lolium multiflorum L.) cv. Comum, trigo (Triticum aestivum L.) duplo propósito cv. BRS Tarumã e ervilhaca peluda (Vicia villosa L.). Avaliaram-se três níveis de luminosidade: a sol aberto (sem presença de árvores de Pinnus taeda), 30% de restrição de radiação (usando espaçamento entre árvores de 15 × 3 m, com 222 árvores/ha) e 60% de restrição de radiação (usando espaçamento de 9 × 3 m, com 370 árvores/ha). Foram realizadas avaliações da produção de forragem, da composição química e dos componentes estruturais das plantas, do potencial hídrico das plantas, da umidade do solo, das variáveis microclimáticas e da produção de acículas. O delineamento experimental foi de blocos completos ao acaso, em parcelas subdivididas e três repetições. O azevém foi a espécie mais produtiva em todos os níveis de luminosidade, embora a ervilhaca tenha apresentado a menor redução de produção quando sombreada. Houve maior potencial hídrico nas plantas e maior umidade no solo nos ambientes sombreados, mesmo assim, a produção de forragem reduziu significativamente no sombreamento mais intenso (81%). A composição química e os componentes estruturais de todas as forrageiras estudadas também são afetados pelo aumento da restrição luminosa.Possible effects of brightness restriction, obtained by different Pinnus taeda tree densities, on the production and quality of black oat (Avena strigosa Schreb) cv. Common, white oat (Avena sativa L.) cv. FAPA 2, annual ryegrass (Lolium multiflorum L.) cv. Common, hairy vetch (Vicia villosa), wheat (Triticum aestivum L.) cv. dual purpose BRS Tarumã were studied. It was evaluated three brightness levels: 1 - full sunlight with no trees; 2 - 30% of radiation restriction, using 15 × 3 m spacing between trees (222 trees/ha), and; 3 - 60% of radiation restriction, using 9 × 3 m between trees (370 trees/ha). It was performed evaluations of forage production, chemical composition and structural component of plants, water potential of the plants, soil moisture, microclimate variables and production of needles. The experimental design was completely randomized blocks, in split-plots and three replicates. Ryegrass was the most productive species at all brightness levels, although hairy vetch showed the lowest reduction on production under shading. There was higher water potential in the plants and higher soil moisture under shading, however, forage production was significantly reduced in the most intense shading (81%). Chemical composition and structural components of all studied forage species are also affected by brightness restriction increase.

Shade in silvopastoral systems improves the thermal comfort of animals, but it may also affect the pasture productivity and can contribute to soil compaction in the shaded areas due to the increase in the number of animals looking for comfort. The effect of grazing at various distances from tree rows (under the tree canopy, at 6 and at 12 m away from the trees) on the soil bulk density and on the aerial and root biomass of Brachiaria decumbens was evaluated in both the dry and the rainy seasons. The study was carried out on an Orthic Ferralsol in a randomized block design with two replications. Tree rows were composed of Eucalyptus grandis and Acacia mangium species, and the paddocks were submitted to a rotational stocking management, using Holstein (Bos taurus) × Zebu (Bos indicus) heifers. The shade intensity in the pasture decreased with an increasing distance from the tree row. Soil bulk density did not vary with the distance from the tree row, but varied seasonally, being greater in the rainy season (1.47 g cm-3) than in the dry season (1.28 g cm-3). Green forage and root mass, expressed as dry matter, were lower under the tree canopy and were greater in the rainy season. There were decreases of 22.3 and 41.4% in the aerial and root biomasses, respectively, in the tree rows. The greatest shoot/root ratio for B. decumbens under moderate and intensive shading indicates a modification in the forage biomass allocation pattern that favours the aerial development in detriment of the root system.O sombreamento em sistemas silvipastoris concorre para o conforto térmico dos animais; no entanto pode afetar a produção do pasto e contribuir para a compactação do solo, pelo aumento da concentração de animais nas áreas sombreadas. Avaliou-se o efeito da distância do renque de árvores (sob a copa das árvores, 6 e 12 m de distancia das árvores) na densidade do solo e na biomassa aérea e de raízes de Brachiaria decumbens, nas épocas seca e chuvosa. O estudo foi conduzido num Latossolo Vermelho-Amarelo no delineamento em blocos casualizados, com duas repetições. A faixa de árvores foi composta pelas espécies Eucalyptus grandis e Acacia mangium, e os piquetes foram manejados com novilhas Holandês (Bos taurus) × Zebu (Bos indicus) , sob lotação rotativa. A intensidade de sombreamento foi decrescente com o distanciamento do renque de árvores. A densidade do solo não variou com a distância do renque de árvores, mas sim com a época do ano, tendo sido maior na época chuvosa (1,47 g dm-3) do que na seca (1,28 g dm-3). As massas secas de forragem verde e de raízes foram menores sob a copa das árvores e maiores na época chuvosa do que na seca. Na faixa arborizada houve reduções de 22,3 e 41,4% na biomassa aérea e de raízes, respectivamente. A maior relação parte aérea/raiz da B. decumbens à sombra expressa uma modificação no padrão de alocação de biomassa na forrageira, que prioriza a formação da parte aérea, em detrimento do sistema radicular.

Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang. é uma espécie clímax tolerante a sombra, ao passo que Enterolobium contortisiliquum (Vell.) Morong. é uma espécie pioneira. O desenvolvimento destas espécies pode refletir a habilidade de adaptação aos diferentes fatores ambientais (luz, água e temperatura) no local em que estão crescendo. O suprimento inadequado de um desses fatores pode reduzir o vigor da planta e limitar seu desenvolvimento. O presente trabalho teve como objetivo avaliar os efeitos do nível de sombreamento no crescimento e a concentração de pigmentos fotossintéticos em duas espécies de leguminosas arbóreas, Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang. e Enterolobium contortisiliquum (Vell.) Morong. O experimento foi conduzido no Setor de Olericultura do Centro Universitário Luterano de Ji-Paraná (CEULJI/ULBRA)/Rondônia. Durante a formação das mudas, ambas as espécies foram expostas a quatro tratamentos de sombra: 0 % (controle - sol pleno); 30 %; 50 % e 80 %. Cada tratamento foi constituído com três repetições de cada espécie; o delineamento experimental foi inteiramente casualisado. Quatro meses após a semeadura, as seguintes análises foram realizadas: número de folhas, altura da planta, comprimento do sistema radicular, massa seca total e concentração de pigmentos fotossintéticos. O tratamento sob sol pleno afetou negativamente o crescimento de ambas as espécies. As mudas crescidas sob 50% e 80% apresentaram melhor desenvolvimento. Conforme o aumento do sombreamento houve um decréscimo na razão clorofila a/b e um aumento nas concentrações de clorofila total e carotenóides totais.Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang. is a clímax shadow tolerant specie and Enterolobium contortisiliquum (Vell.) Morong., by the other hand, is considered as a pioneer specie. The development of these species may reflect its adaptation ability to different environmental elements (light, water and temperature) at its growth site. An inadequate supply of some of these elements may reduce plant vigor and limit its development. This work aimed to evaluate the effects of shade intensity on the growth and photosynthetic pigment concentration of two arboreal legumes that are typical to northern Brazil, namely, the Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang. and the Enterolobium contortisiliquum (Vell.) Morong. The experiment was carried out at the Centro Universitário Luterano de Ji-Paraná (CEULJ/ULBRA)/Rondônia. During the formation of the seedlings, both species were exposed to four treatments of shade: 0 % (control - without shade); 30 %; 50 % e 80 %. Each treatment was carried out with three replications for each species; the experimental design was completely randomized. Four month after sowing, the following analyses were carried out: number of leaves, plant height, roots length, dry mass and photosynthetic pigment concentration. The treatment under 0% shade impaired the seedling growth of both species. The most favorable treatments were 50 % and 80 % shade. According to the shade intensity, the chlorophyll a/b ratio decreased and the chlorophyll and carotenoids increased.

A Alfavaca-cravo é uma espécie medicinal produtora de óleo essencial de elevada eficácia no combate de diversos organismos patogênicos. Por isso, o entendimento do comportamento fisiológico dessa espécie e as respostas desse comportamento às condições do ambiente tornam-se necessários ao aperfeiçoamento dos métodos de cultivo. Nesse contexto, este estudo objetivou avaliar o efeito da intensidade e qualidade da luz nos teores de clorofila e carotenoides e na estrutura de cloroplastos de Alfavaca-cravo, Ocimum gratissimum L. As plantas com 5,0-6,0cm foram submetidas aos seguintes tratamentos: pleno sol, sombreamento 50% sob malha azul, malha vermelha e malha preta durante 120 dias. As concentrações de clorofilas e carotenoides foram avaliadas por espectrofotometria, e as estruturas dos cloroplastos foram analisadas pela microscopia de transmissão. As plantas mantidas a pleno sol tiveram os menores teores de clorofila a e b e o maior teor de carotenoides, enquanto aquelas cultivadas sob malha preta tiveram a maior concentração de clorofila a e b. A menor densidade de cloroplastos foi encontrada nas plantas sob malha preta. Nos tratamentos com 50% de sombreamento, foram verificados cloroplastos mais alongados. As plantas de alfavaca-cravo crescidas a pleno sol e sob malha azul tiveram cloroplastos com maiores áreas e grãos de amido com maiores perímetros. As mudanças nas concentrações dos pigmentos e na estrutura dos cloroplastos evidenciaram uma adaptação da Alfavaca-cravo à variação de intensidade e qualidade da luz. Isso pode auxiliar no desempenho fotossintético sob diferentes condições luminosas.The Alfavaca-cravo is a medicinal specie which produces an essential oil effective in the combat of several organisms. Therefore, the understanding of the physiologic behavior and physiological responses of this behavior to environmental conditions becomes necessary to improve methods of cultivation. In this context, the aim of this study was to evaluate the effect of the intensity and quality of the light on concentration of chlorophyll and carotenoids and on chloroplasts structure of Alfavaca-cravo (Ocimum gratissimum L.). The plants with 5.0-6.0cm were submitted to the following treatments: full sunlight and 50% of shade under blue, red and black nets during 120 days. The chlorophyll and carotenoids concentration were analyzed through spectrophotometer and the structure of chloroplast was analyzed by transmission microscopy. Plants maintained under full sunlight had the lowest chlorophyll a and b concentration and the highest carotenoids concentration. However, plants cultivated under black net had the highest production of chlorophyll a and b. The lowest chloroplasts density was found in plants under black net. In the treatments with 50% of shade was verified more elongated chloroplasts. Alfavaca-cravo plants grown under full sunlight and blue net had chloroplasts with larger areas and starch grains with larger perimeters. The changes on the pigments concentration and structure of chloroplasts showed a chromatic adaptation of Alfavaca-cravo to the variation of the intensity and quality of the light. This can improve photosynthetic performance under different luminosity conditions.

O objetivo deste trabalho foi avaliar as características do pasto e o desempenho de novilhas oriundas do cruzamento Holandês x Zebu, em sistema silvipastoril (SSP) e em monocultivo de braquiária (Urochloa decumbens). O delineamento experimental foi o de blocos ao acaso, com dois tratamentos: em monocultivo de braquiária; e o SSP, que apresentava faixas de braquiária consorciada com Stylosanthes guianensis, alternadas com faixas arborizadas. Os piquetes foram manejados sob lotação rotacionada, com 7 dias de ocupação e 35 e 49 dias de descanso, nas épocas chuvosa e seca, respectivamente. As características do pasto, o consumo e o ganho de peso não variaram com o sistema; porém, devido às reduções na quantidade e no valor nutritivo da forragem, apresentaram valores maiores na época chuvosa do que na época seca, respectivamente: massa de forragem pré-pastejo, 1.525 e 964 kg ha-1; teores de proteína bruta na gramínea, 9,3 e 8,2%; digestibilidade in vitro da matéria seca, 56,1 e 50,3%; consumo de matéria seca, 2,3 e 1,6% do peso vivo; ganho de peso de 625 e 242 g por dia por novilha. O sombreamento moderado no SSP não interferiu nas características do pasto, nem no consumo de forragem, nem no desempenho de novilhas leiteiras, quando comparado aos valores obtidos na pastagem de braquiária em monocultivo.The objective of this work was to evaluate the pasture characteristics and the performance of heifers from the Holstein x Zebu cross in a silvopastoral system (SPS), and in a Brachiaria (Urochloa decumbens) pasture. The experiment was set up in a randomized block design with two treatments: an exclusive Brachiaria pasture; and SPS, which had mixed U. decumbens and Stylosanthes guianensis strips alternating with strips with trees. Paddocks were grazed in rotational stocking, with seven days of grazing and 35 and 49 days of rest in the rainy and dry seasons, respectively. Pasture traits, dry matter intake and live weight gain did not vary with the systems. However, due to the reduction in the amount and nutritional value of the forage, these variables had higher values for the rainy season than the dry season, respectively: pre-grazing forage mass, 1,525 and 964 kg ha-1; crude protein, 9.3 and 8.2%; in vitro dry matter digestibility, 56.1 and 50.3%; dry matter intake, 2.3 and 1.6% of body weight; and live weight gain, 625 and 242 g per day per heifer. Moderate shading in SPS did not affect pasture traits, dry matter intake, or the performance of the heifers, in comparison to the values obtained for an exclusive Brachiaria pasture.

Avaliou-se a degradabilidade in situ da matéria seca (MS) da Brachiaria brizantha cv. marandu colhida em dois sistemas silvipastoris compostos pelas arbóreas, ipê felpudo (Zeyheria tuberculosa) e aroeira (Myracrodruon urundeuva), localizados no bioma Cerrado, município de Lagoa Santa, MG. O período de coleta da forragem foi de dezembro de 2004 a abril de 2005. O delineamento utilizado foi em blocos ao acaso, segundo esquema de parcelas subdivididas, sendo as parcelas os tratamentos e as sub-parcelas os tempos de degradação. O sombreamento com as arbóreas não influenciou a degradabilidade in situ da matéria seca da forrageira.In situ degradability of dry matter of Brachiaria brizantha cv. marandu harvested in two silvopastoral systems was evaluated. One system was composed by Zeyheria tuberculosa tree and the other by Myracrodruon urundeuva, both located at Brazilian Savannah, Lagoa Santa, MG. A completely ramdomized block experimental design in a splitplot arrangement was used. The treatments were allocated in the plots and the times in the splitplot. No effect of shade was observed for in situ dry matter degradability.