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na integração lavoura-pecuária-floresta e duas testemunhas em monocultivo (eucalipto e acácia). A altura das árvores de eucalipto é influenciada pelo consórcio com acácia nos arranjos estudados na ILPF, o que não acontece com o diâmetro à altura do peito. O arranjo das espécies de eucalipto e acácia consorciados na mesma linha de plantio possui produtividade igual ao arranjo, utilizando apenas eucalipto nas linhas de plantio em sistemas de ILPF. A produtividade de madeira de eucalipto no arranjo de eucalipto e acácia na mesma linha da ILPF é menor do que em cultivo sozinho na linha, porém, a soma da madeira produzida pelas duas espécies é superior ao arranjo de apenas eucalipto na linha de plantio da ILPF. PRODUCTIVE BEHAVIOR OF EUCALYPTUS AND ACACIA, IN DIFFERENT ARRANGEMENTS OF CROP-LIVESTOCK-FOREST INTEGRATION ABSTRACT:The objective was to evaluate initial growth of clonal Eucalyptus, hybrid Eucalyptus grandis x E. urophylla and Acacia (Acacia mangium) trees in alternate and not alternate rows of trees, intercropped with forage (crop-livestock-forest integration -CLFI) and monoculture. The design was a randomized complete block design with four replications, three arboreal arrangements consisting of eucalyptus, acacia + eucalyptus, acacia, all planted in crop-livestock-forest integration and two monoculture controls (Eucalyptus and Acacia). The height of eucalyptus trees is influenced by the consortium with Acacia in the studied CLFI designs, which does not happen with the diameter at breast height. The arrangement of species of eucalyptus and acacia intercropping in the same row planting has productivity equal to the array using only the lines of eucalyptus planting systems . Timber productivity of acacia and eucalyptus in the same row is less than the same species line, however, the sum of the timber produced from the two species is greater than the arrangement of eucalyptus only row in CLFI.

Componentes produtivos do milho sob diferentes manejos de plantas daninhas e arranjos de plantio em sistema... Ciência Rural, v.45, n.9, set, 2015. 1545Componentes produtivos do milho sob diferentes manejos de plantas daninhas e arranjos de plantio em sistema agrossilvipastoril

Comportamento de

This study aimed to assess the effects of Eucalyptus and maize shading on characteristics related to water use by Brachiaria in agroforestry systems. Treatments were arranged in a split-split-plot design, with plots consisting of different spacing between Eucalyptus plants (12.0×2.0m and 12.0×4.0m), split-plots of different distances between Brachiaria and Eucalyptus (6.0, 4.0, and 2.0m), and split-split-plots of Brachiaria sowing sites (maize row and inter-row). One treatment with Brachiaria under full sunlight was included. Bread grass intercropping in maize inter-rows associated with the densest Eucalyptus spacing and bread grass proximity to Eucalyptus tree crowns adversely affected the stomatal conductance, internal carbon, and transpiration rate of bread grass. Water use efficiency of bread grass intercropped in maize rows decreased, regardless of the Eucalyptus plot design and distance between forages and trees.

The use of herbicides to control grass in Medicago sativa (alfalfa) pastures is still incipient. Therefore, the objective of this study was to evaluate the efficiency of fluazifop-p-butyl in the control of Brachiaria decumbens (signalgrass) in alfalfa. Thus, randomized block design was used, with seven doses of fluazifop-p-butyl (0, 25, 50, 100, 200, 300, 400 g ha-1), and four replications. Herbicide application was performed when the plants had about 20 cm height. Chlorophyll fluorescence, control of signalgrass and alfalfa toxicity were evaluated at 7, 15 e 30 days after application (DAA) and, at 45 DAA and 45 days after cut (DAC), both species were cut and tiller density, as well as branches and dry matter of forage species, were determined. Fluazifop-p-butyl does not affect the integrity of the photosynthetic apparatus of alfalfa plants, due to high tolerance to this mechanism of action presented by dicotyledonous species. However, signalgrass had physiological variables negatively affected by the herbicide, indicating the presence of physiological stress, even at the lowest doses of the product. The dose of 50 g ha-1 of fluazifop-p-butyl is effective in controlling signalgrass, without causing physiological and growth damage in alfalfa plants.

RESUMO -Objetivou-se com o presente trabalho avaliar o consórcio de forrageiras e sorgo, cultivado na presença ou na ausência do herbicida atrazine, sobre a dinâmica de plantas daninhas e a produção de sorgo e das forrageiras em um sistema agroflorestal. O experimento foi disposto em delineamento com blocos casualizados, com três espécies de forrageiras (Brachiaria brizantha cv. Xaraés; Andropogon gayanus e Panicum maximum cv. Tanzânia) consorciadas com sorgo manejado na presença e na ausência da aplicação de 1,50 kg ha -1 de atrazine para o manejo de plantas daninhas. As forrageiras foram semeadas a lanço imediatamente antes da semeadura do sorgo, em espaçamento de 0,50 m entre linhas e com oito sementes por metro linear, em sistema de plantio direto. A aplicação de atrazine não resultou em menor produção de massa seca total de plantas daninhas, quando comparada às parcelas sem manejo. A maior massa seca das plantas daninhas foi encontrada no monocultivo de sorgo, quando comparado aos consórcios dessa cultura com as forrageiras. No consórcio do sorgo com o capim-tanzânia (forrageira de maior produção) obteve-se a menor ocorrência e produção de masssa de plantas daninhas, indicando boa capacidade competitiva dessa forrageira. A produção do sorgo não diferiu estatisticamente entre os tratamentos; entretanto, ela foi 22% superior no monocultivo, comparando-se aos consórcios com as forrageiras. As espécies de maior produção de massa, como o capim-tanzânia, quando consorciadas com o sorgo, diminuem a infestação e capacidade competitiva das plantas daninhas e favorecem o manejo dessas espécies, dispensando a aplicação de atrazine.Palavras-chave: pastagens, manejo cultural, produção de sorgo e sistemas integrados.ABSTRACT -This study aimed to evaluate the effect of a consortium of forage plants and sorghum in the presence or absence of the herbicide atrazine on weed dynamics, sorghum and forage plant production, in an agro-forestry system. The experiment was arranged in a randomized block design, with three grass species (Brachiaria brizantha, cv. Xaraés; Andropogon gayanus cv. Planaltina and Panicum maximum, cv. Tanzânia) in consortium with sorghum, and in the presence and absence of 1.50 kg ha -1 of atrazine application for weed management. The forage plants were sown before sorghum, spaced 0.50 m between rows and eight seeds per linear meter, under a no-tillage system. The application of atrazine did not result in lower production of total dry mass of weeds, compared to the plots without management. The highest weed dry mass was found in the sorghum monoculture, compared to consortium of this culture with the forage plant. The planting of sorghum with Tanzania grass, the forage plant with the largest production, was obtained in the occurrence and mass production of weeds, indicating a good competitive ability of this forage plant. Sorghum production was statistically similar between treatments but higher in monoculture, compared to the consortium with forage. The species presenting higher mass production, such as T...

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