Post-emergence nicosulfuron application enhanced leaf-stem ratio in maize-intercropped with Urochloa species after shading and sunlight re-exposure.

Low rates of nicosulfuron used in post-emergence provide an advantage to maize during the coexistence of the crops, when maize is intercropped with Urochloa grasses. Nonetheless, the effect of this practice on the morphology of these grasses is not known, neither how it affects forage growth after the coexistence period nor when the grass is re-exposed to full sunlight. The aim of this study was to determine biomass and leaf-stem ratio of Urochloa hybrid cv. Mulatto II (CIAT 36087), Urochloa brizantha (Hochst. ex A. Rich.) and Urochloa ruziziensis (Germ. & Evrard) after the development in a shade simulated environment promoted by maize in intercrop systems. The treatments consisted of three brachiaria species with two herbicides managements. Evaluations occurred at 0, 30 and 60 days after the sunlight re-exposure (DASR). Nicosulfuron application and Urochloa species did not affect biomass yield. However, herbicide increased leaf-stem ratio of the species between 25% at 0 DARS to 62% at 30 DARS on old tillers (tillers that grew under shade). The biomass yield, as well the leaf-stem ratio of the new tillers was not affected. Among the species, the greater ratio of leaves in the plant biomass was recorded for Urochloa brizantha (Hochst. ex A. Rich.) and Urochloa hybrid cv. Mulatto II (CIAT 36087). Nicosulfuron use in post-emergence enhanced the leaf-stem ratio of Urochloa grasses after sunlight re-exposure and a reliable alternative to improve forage quality in intercrop systems

Contribution of corn intercropped with Brachiaria species to nutrient cycling.

The corn biomass and nutrient dynamics may be altered when it is intercropped with Brachiaria (syn. Urochloa spp.). The present study aimed to investigate the dynamics of biomass, nitrogen (N), phosphorus (P) and potassium (K) for farming systems that produce corn intercropped with Brachiaria species. Field experiments were performed during the season and off-season, in a split-plot design. The main plots were composed of Brachiaria species (B. brizantha, B. ruziziensis and B. Convert) intercropped with corn, in addition to corn monocropping. The subplots consisted of three forage sampling periods, ranging from 0 to 60 days after the corn harvest. The intercropping arrangements did not affect the corn grain yield, nutrient accumulation and partitioning, relatively to the corn monocropping. After the grain harvest, B. brizantha achieved the greater biomass accumulation rate in both the season (69 kg ha-1 day-1) and off-season (17 kg ha-1 day-1). The nutrient accumulation ranged widely between the Brachiaria species and planting seasons: 0.2-1.2 kg ha-1 day-1 for N; 0.01-0.07 kg ha-1 day-1 for P; and 0.13-0.8 kg ha-1 day-1 for K. However, the greatest nutrient accumulation was found for B. brizantha, followed by B. ruziziensis and then B. Convert. In the short-term, corn intercropped with Brachiaria in the season showed the largest effect on the nutrient cycling and biomass yield. The intercropping between corn and B. brizantha in the season was the best way to enhance the biomass yield and the N, P and K cycling

Morphological characterisation and agronomical parameters of different species of Salvia sp. (Lamiaceae)

The aim of this work is to assess the morphological characteristics and parameters of biomass production, such as fresh and dry matter weight (FMW and DMW, g/plant), yield of dry matter (YDM) in terms of ton/ha, essential oil content (EOC, mL/100 g) and yield of essential oils (YEO) expressed as L/ha of the following plants Salvia verbenaca, Salvia argentea, Salvia lavandulifolia, Salvia pratensis, Salvia sclarea, Salvia triloba and Salvia officinalis. Except for Salvia argentea (S2) all other species have adapted to the south Brazilian climate conditions, with morphological differences among the species evaluated. In terms of DMW and YDM, S. officinalis was found to be the most productive species with 445.83 g/plant and 11.14 ton/ha. The higher essential oil content and yield was observed for S. officinalis, affording 1.99 mL/100 g and 221.74 L/ha, respectively. Chemical characterisation of the essential oils obtained from hydrodistillation was performed through GC and GC/MSD analyses, which revealed for most of the species studied, α e β-thujone, camphor and 1,8-cineole as major compounds, apart from S. sclarea, for which linalool, linalyl acetate and α-terpineol were the major components