Brachiaria sp. grasses are widely used in planted pastures in Brazil. ‘Mulato II’ is a productive Brachiaria hybrid (B. ruziziensis × B. decumbens × B. brizantha) with high nutritive value, but it has not been evaluated under continuous stocking in Brazil, despite this method being widely used by producers. The objectives of this research were to quantify the effects of three canopy heights (10, 25, and 40 cm), maintained by mimicking continuous stocking, and two N rates (50 and 250 kg ha–1 yr–1) on herbage accumulation (HA), grazing efficiency (GE), and nutritive value of Mulato II during two summer rainy seasons in Piracicaba, Brazil. The N rates were chosen so that canopy height effects could be evaluated under distinctly different grass growth rates. Grass HA increased linearly (8640 to 13,400 kg DM ha–1 yr–1), in vitro digestible organic matter (IVDOM) decreased linearly (652 to 586 g kg–1), and GE decreased (linear and quadratic; 65 to 44%) as canopy height increased. There were no height × N rate interactions for these responses. Mulato II was less productive (7940 vs. 13 380 kg ha–1 yr–1) and had lesser IVDOM (581 vs. 652 g kg–1) at the lower N rate. Thus, although GE and IVDOM were greatest for 10 cm, HA was 36% less for the 10‐ than the 40‐cm height, and despite greatest HA occurring at 40 cm, both GE and IVDOM were greater at shorter heights. These data suggest that ∼25‐cm canopy height is optimal for continuously stocked Mulato II.

Brachiaria and Cynodon are important pasture grasses in Brazil. Convert HD 364 (Dow AgroSciences, São Paulo, Brazil) brachiariagrass (Brachiaria hybrid CIAT 36087; also known as Mulato II) is a new hybrid released for use in a broad range of environments. It has high nutritive value and yield, but there are no year‐round comparisons, including the dry season, with other pasture grasses. Forage accumulation and crude protein (CP), neutral detergent fiber (NDF), and in vitro digestible organic matter (IVDOM) concentrations were evaluated for Convert HD 364, Marandu palisadegrass {B. brizantha (Hochst. ex A. Rich.) R. D. Webster [syn. Urochloa brizantha (A. Rich.) Stapf]; CIAT 6297}, and Tifton 85 bermudagrass (Cynodon spp.) during dry and rainy seasons from 2011 to 2013. Irrigated and rainfed plots were harvested every 28 and 42 d. Convert HD 364 had similar or greater forage accumulation (17.9–22.8 Mg DM ha−1) than Marandu and Tifton 85 (15% greater than Marandu and 12% greater than Tifton 85 when irrigated and harvested every 28 d). Tifton 85 CP concentration was 140 g kg−1, greater than that of the other grasses when harvested every 28 d and irrigated. Convert HD 364 (537 g kg−1) NDF concentration was least, regardless of irrigation, harvest frequency, or season. This was associated with IVDOM concentration greater than 650 g kg−1, similar to that of Marandu. Convert HD 364 is a viable option for diversification of pasture‐based animal production systems in tropical areas due to high forage accumulation and nutritive value when fertilized and well managed.

The effects of three canopy heights (10, 25 and 40 cm) and two N rates (50 and 250 kg ha−1 year−1) on herbage accumulation (HA), participation of leaf categories in the leaf area index (LAI) and photosynthesis of grazed “Mulato II” brachiariagrass (Brachiaria brizantha × B. decumbens × B. ruziziensis) were investigated during two summer growing seasons in Piracicaba, São Paulo, Brazil. The HA and LAI increased linearly from 8560 to 13600 kg DM ha−1 year−1 and 2.3 to 5.5 m2 m−2, respectively, as canopy height increased. Mulato II brachiariagrass maintained at 10 cm canopy height showed greater proportion of young leaves, but was less productive than taller canopies. Taller canopies had greater proportion of mature leaves in the LAI as well as greater photosynthesis. The greater N rate contributed to increased LAI, leaf and canopy photosynthesis rates and HA but did not affect the LAI composition. The total leaf area is more important to HA than the proportion of young leaves in the LAI, as taller canopies were more productive, suggesting that maintaining Mulato II brachiariagrass at 25 or 40 cm is advantageous for this grass.

Pasture management, including the control of grazing intensity and fertilization, can trigger plant physiological and morphological responses that affect plant growth and impact stand persistence. The objective of this research was to quantify the effects of three canopy heights (10, 25, and 40 cm), maintained by mimicking continuous stocking, and two N rates (50 and 250 kg ha−1 yr−1) on canopy carbon exchange rate (CER), plant‐part accumulation, and organic reserves of ‘Mulato II’ brachiariagrass hybrid (Brachiaria brizantha × B. decumbens × B. ruziziensis), also known as Convert HD 364 (Dow AgroSciences, São Paulo, Brazil) during two summer rainy seasons in Piracicaba, Brazil. Leaf CER was greater for the 10‐cm height, but canopy CER, plant‐part accumulation, root mass, and root reserves were less in 10‐ than 40‐cm canopies, although this was not associated with stand deterioration after 2 yr. Leaf was the predominant plant part, and leaf accumulation rate increased linearly from 70 to 100 kg dry matter (DM) ha−1 d−1 as canopy height increased from 10 to 40 cm. Increasing N rate from 50 to 250 kg N ha−1 yr−1 affected plant growth, increasing CER, leaf area index, and the rates of leaf, stem, and dead herbage accumulation. The senescence‐to‐growth ratio (S:G) was not affected by N rate, indicating that the increase in rate of dead material accumulation with greater N rate was a result of an increase in the accumulation rates of all plant parts. Taller canopy heights (25 or 40 cm) are recommended for Mulato II under continuous stocking.

Long-term stand persistence is a desirable characteristic of sustainable grassland ecosystems, and tillering dynamics is an important determinant of persistence. Grazing intensity and nutrient supply affect tiller density, weight, and survival. Understanding the relationships among these factors can help optimize performance of grazed pastures. The objective of this research was to determine the effects of canopy height (10, 25, and 40 cm; maintained under mimicked continuous stocking) and N fertilization (50 and 250 kg ha −1 yr −1 ) on the tiller dynamics and canopy stability index (SI) of 'Mulato II' hybrid brachiariagrass (Brachiaria spp. syn. Urochloa spp.) during two growing seasons. Tiller population density (TPD) increased by 9% with greater N fertilization and decreased linearly from 1,130 to 900 tillers m −2 as canopy height increased from 10 to 40 cm. Tiller weight (TW) increased from 0.39 to 1.46 g as canopy height increased from 10 to 40 cm, but TW decreased by 9% with a greater N rate. Tiller appearance rate increased by 30% and tiller survival rate (TSR) decreased by 13.5% as N rate increased. The TSR was greater for 25-and 40-cm than for 10-cm canopies (81, 82, and 74 tillers per 100 tillers per 30 d, respectively). The SI increased from 0.91 to 1.0 with increasing canopy height from 10 to 40 cm. Mulato II canopies followed the tiller size-density compensation mechanism, displaying phenotypic plasticity in response to canopy height, but these results suggest a 25-cm canopy height is near optimal for continuously stocked Mulato II brachiariagrass pastures.