The objective of this work was to evaluate the effects of different arrangements of eucalyptus plants on the morphoanatomical characteristics of leaf blades of 'Marandu' grass [(Urochloa brizantha (Syn. Brachiaria brizantha)] plants cultivated in agrosilvopastoral systems. The experiment was set in field conditions in a randomized complete block design with four replicates, in which the plots were represented by planting spacings of eucalyptus (12x2 and 12x4 m), and the subplots, by the distance between 'Marandu' grass and eucalyptus rows (6, 4, and 2 m). A control was added, composed by 'Marandu' grass cultivated in full sun. Variables of the leaf anatomy of 'Marandu' grass were evaluated for shading interference by trees. The distance of 'Marandu' grass plants from the eucalyptus lines interfered with the leaf blade anatomy of the forage, and the highest modifications occurred in linear measures and tissue proportions in the arrangements with the highest eucalyptus density. The shading interference of eucalyptus on the anatomical characteristics of leaf blades of 'Marandu' grass depends on the adopted arrangement. This occurs due to the grass adaptation to the low-light incidence, with a consequent reduction in its physiological activity and growth.

In pastures, the incidence of weeds reduces the productivity and quality of forage. The identification of the weed species in pastures is fundamental to choose the renewal method. Thus, the objective of this work was to perform phytosociology before and after the renewal of a Brachiaria decumbens pasture, with the implantation of agrosilvopastoral systems. Eighteen different crop arrangements for pasture renewal were evaluated. The renewal systems were by eucalyptus integration (at 12 x 2 m or 12 x 3 m spacings) with maize, Brachiaria brizantha cv. Marandu (palisade grass) and/or Macrotyloma axillare (perennial horsegram), or monoculture and intercropping of palisade grass and perennial horsegram, as well as the evaluation of the application or not of the herbicide bentazon, at the recommended dose for maize crops (0.72 kg ha-1). Relative frequency, relative density, relative abundance, relative dominance, coverage value index, importance value index, dry matter and similarity index were evaluated. In the first survey, before the pasture renewal, 23 plant species were identified. After the implantation of agrosilvopastoral systems, the species Sida cordifolia, Lantana camara and B. decumbens were the only occurring ones before and after the renewal of the pasture with agrosilvopastoral systems. The use of palisade grass and the application of the herbicide were efficient in controlling weeds. In systems that contained palisade grass and perennial horsegram, the latter was not found in the survey conducted one year after the implantation.

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The objective of this work was to evaluate the morphogenetic, structural, physiological, and productive traits of forage peanut (Arachis pintoi) subjected to different levels of artificial shading in the field. The 'Amarillo MG-100' forage peanut was planted in April 2015, and the evaluations were carried out from May 2017 to April 2018. The treatments were: 0, 30, 45, and 75% of artificial shading. There was no significant effect of shading on the morphogenetic traits of forage peanut. Shading increased final leaf length and canopy height and decreased the leaf area index and number of stolons. Photosynthesis, transpiration rate, stomatal conductance, chlorophyll b, and leaf temperature increased quadratically as a function of shading. There was a linear positive effect on the growing cycle length and a quadratic effect on the production of dry matter mass, with the maximum at 30% shade. Forage peanut harvested at 95% light interception (11-cm height) shows adaptation to shading up to 45%, with increased leaf size, canopy height, photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll b. In addition, plants at 30% shading show a higher yield than those growing under full sun.

Integrated systems have been gaining prominence in recent years, especially the crop-livestock-forestry, which, in addition to being an alternative income per area, increase fertility and organic matter content in the soil, and protect animals against weather conditions. However, there is still a lack of knowledge about the management of pastures under such conditions. Therefore, the aim of this research was to evaluate the grazing management and nitrogen fertilization in Marandu palisade grass consorted with Eucalyptus to obtain the greater of forage production. The experimental design was a randomized block, arranged in split-plot, the plots were composed of two eucalyptus spacing (12 x 2 or 12 x 3) and Marandu monoculture, the subplots were composed of the nitrogen fertilization rate (0, 100, 200 kg N/ha using ammonium sulfate). The higher DM accumulation rate was observed at 200 kg N ha-1 (69.29 kg DM ha-1 day), while there was no difference between the treatments without fertilization and 100 kg N ha-1 (P > 0.001). DM accumulation rate increased by 30.01% when fertilization increased from 100 kg N ha-1 to 200 kg N ha-1. Marandu palisade grass with 200 kg N ha-1 showed the highest production (28.82 t ha-1) independent of spacing. In the silvopastoral system, the greater accumulation of forage was observed when handled with 80% of the light interception (LI), corresponding to a height of 67 cm. Therefore, we conclude that Marandu grass in a silvopastoral system, without N fertilization, should be managed with a pre-grazing height of 60 cm and 73% LI. Marandu grass in a silvopastoral system, with 100 kg N ha-1 fertilization, should be managed with a height of 68 cm and 84% LI, and, with 200 kg N ha-1, should be managed at 80% of LI for the greater pasture utilization and development.

The aim of this work was to study the effect of sub-doses of herbicide nicosulfuron on the levels of chlorophyll and growth of marandu-grass in an forest-livestock integration system. The treatments consisted of eucalyptus consortium with sorghum (BRS 655 hybrid) and forage Urochloa brizantha cv. Marandu (marandu-grass) at 12×2 and 12×3 m spacings in agroforestry systems, in addition to sorghum + marandu-grass and marandu-grass in monoculture. The doses of nicosulfuron applied at the marandu-grass were 0, 15 and 30 g ha-1. At 30 and 120 days after the application of nicosulfuron, chlorophyll a and chlorophyll b were measured usinf a portable chlorophyll meter, with six measurements per plant. Afterwards, the total chlorophyll content and chlorophyll a/b were calculated. We also measured the mass of the total dry matter of marandu-grass and growth rate of the culture. Marandu-grass plants cultivated in monoculture showed higher quantities of chlorophyll and the highest growth rates. The levels of chlorophyll a, b and chlorophyll a/b and the growth rate of marandu grass were similar between systems integrated with eucalyptus (12x2 and 12x3 m). The increase of herbicide dose negatively influenced on chlorophyll content in marandu-grass in all treatments evaluated. The use of nicosulfuron in doses of 25 and 50 g L-1 reduced the growth rate of marandu grass only when grown in monoculture