Xaraés palisadegrass remains productive after the disappearance of stylo in tropical legume-grass pasture

Gradual reduction of legumes in mixed tropical pastures requires periodic oversowing. Exploiting the carrying capacity of grass for an extra year after the disappearance of legumes can be economically advantageous to the farmer. This study aimed to evaluate the productivity of Xaraés palisadegrass (Brachiaria brizantha) pastures in response to its historical association with stylo (Stylosanthes guianensis) under two canopy heights to determine whether different grazing management conditions affect the defoliation pattern left by grazing animals. The split-plot experimental design was used, with the historical botanical composition (HBC) (24, 34, 45 and 52 % legume composition) corresponding to the main plots and the canopy frequency of defoliation determined at heights of 30 and 45 cm for Xaraés palisadegrass corresponding to the subplots with two replicates (500 m2) grazed by Tabapuã cows. Pastures with over 34 % stylo in the botanical composition remained productive for one year after legume disappearance, accumulating more than 8 mg ha−1 of forage per year. Xaraés palisadegrass pastures at a height of 30 cm provided better canopy structure, with 64 % less stem production and 43 % less dead material. The 30-cm pre-grazing canopy height provided a grazing environment conducive to forage intake by animals that resulted in efficient use of the pasture. In response to the improved canopy structure, the cows grazed an average of 60 fewer minutes. A HBC greater than 34 % of legumes in the pastures allows for the postponement of legume oversowing until the next growing season

Xaraés palisadegrass remains productive after the disappearance of stylo in tropical legume-grass pasture

Gradual reduction of legumes in mixed tropical pastures requires periodic oversowing. Exploiting the carrying capacity of grass for an extra year after the disappearance of legumes can be economically advantageous to the farmer. This study aimed to evaluate the productivity of Xaraés palisadegrass (Brachiaria brizantha) pastures in response to its historical association with stylo (Stylosanthes guianensis) under two canopy heights to determine whether different grazing management conditions affect the defoliation pattern left by grazing animals. The split-plot experimental design was used, with the historical botanical composition (HBC) (24, 34, 45 and 52 % legume composition) corresponding to the main plots and the canopy frequency of defoliation determined at heights of 30 and 45 cm for Xaraés palisadegrass corresponding to the subplots with two replicates (500 m2) grazed by Tabapuã cows. Pastures with over 34 % stylo in the botanical composition remained productive for one year after legume disappearance, accumulating more than 8 mg ha−1 of forage per year. Xaraés palisadegrass pastures at a height of 30 cm provided better canopy structure, with 64 % less stem production and 43 % less dead material. The 30-cm pre-grazing canopy height provided a grazing environment conducive to forage intake by animals that resulted in efficient use of the pasture. In response to the improved canopy structure, the cows grazed an average of 60 fewer minutes. A HBC greater than 34 % of legumes in the pastures allows for the postponement of legume oversowing until the next growing season

Update of the Brazilian floristic list of Algae and Cyanobacteria

Abstract An updated synthesis of cyanobacteria and algae information is presented for Brazil aiming to refine the data gathered to date and evaluate the progress of the biodiversity knowledge about these organisms in the country since the publication of the Catálogo de Plantas e Fungos do Brasil. The results of 2015 showed an increase of 1,250 species (35.7%) when compared to 2010, reaching a total of 4,747 species. The most diverse classes in species number were the Bacillariophyceae, Conjugatophyceae, Florideophyceae, Cyanophyceae, Dinophyceae and Euglenophyceae. Bacillariophyceae and Cyanophyceae had the highest increase in species number in the five-year interval. The Southeast and South regions were the most diverse, however, the Northeast, with the states of Piauí and Sergipe, and the Central-west region, with Mato Grosso, Goiás and Distrito Federal, also stood out in the national algal biodiversity scenario. Despite the shortage of taxonomists and limited infrastructure, the results showed a significant improvement in the knowledge regarding the diversity of cyanobacteria and algae in the country during the study period, starting to even out regional geographical differences caused by subsampling