-This study was conducted in order to verify if the phenological stage and the nitrogen fertilization interfere in the allelopathic activity and in the concentration of potentially allelopathic phenolic compounds of tough lovegrass (Eragrostis plana). The assay consisted of a bifactor 3 (0.100 and 200 kg N ha -1 ) x 2 (harvested in vegetative and reproductive stages), in a split plot design. The N doses constituted the main plot and the phenological stage during the harvest the subplots, resulting in six treatments. The tough lovegrass plants derived from each of the treatments were subjected to allelopathy bioassays, in which aqueous extracts of the aerial parts were applied to lettuce cypselae (Lactuca sativa) and to phytochemicals tests when ethanolic extracts were used, with subsequent partition with ethyl acetate, followed by a high-performance liquid chromatography analysis. There was nitrogen x phenological stage interaction on biological and chemical attributes. The allelopathic extracts were, in descending order of inhibition of germination, those from plants harvested at the vegetative stage and fertilized with 100 kg N and at the flowering stage with 200 kg N, which showed the highest catechin concentrations. The caffeic, ferulic, p-coumaric and vanillic acids were in a higher concentration in flowered and fertilized plants with 0 or 200 kg N. The management of the nitrogen fertilization and the harvesting age influence the allelopathic activity and the phytochemical composition of tough lovegrass.Keywords: germinability, phenolic acids, catechin, epicatechin. RESUMO -Este estudo foi realizado com o objetivo de verificar se a fenologia e a adubação nitrogenada interferem na atividade alelopática e na composição fenólica do capim-annoni (Eragrostis plana

-The objective of this work was to evaluate the dominance, growth and bromatology of tough lovegrass or 'annoni' grass (Eragrostis plana) in secondary vegetation area. The evaluations were carried out at 23, 45, 64, 86, 111, 132, 153, and 174 days of growth after a mowing. The tough lovegrass was the dominant species on the area, accounting for 76 to 90% of biomass. There was a linear increase for leaf (9.8 kg DM ha -1 day -1) and total dry mass (16.9 kg DM ha -1 day -1) of the tough lovegrass. During the 111 days of the vegetative stage, the biomass was composed only of leaves, and the flowering started at 132 days. At 174 days, the tough lovegrass accumulated about 4,000 kg DM ha -1 , 650 kg DM ha -1 of which was composed of inflorescences. The growth analysis revealed a specific leaf area of 72 cm 2 g -1 and a maximum leaf area index of 2.1. The leaf area ratio decreased from 72.2 to 43.9 cm² g -1 between the 23 rd and 174 th days. The bromatological analysis showed a high content of neutral detergent fiber (85.3-90.4%) and acid detergent fiber (39.4-42.8%), as well as low crude protein content (3.9-9.9%), indicating the low forage quality of the species. entre o 23º e o 174º dia após o corte. A análise bromatológica mostrou elevados teores de fibra em detergente neutro (85,3-90,4%) e fibra em detergente ácido (39,4-42,8%), e baixo teor de proteína bruta (3,9-9,9%), indicando a baixa qualidade nutricional do capim-annoni.Palavras-chave: Fibra. Índice de área foliar. Massa seca. Proteína bruta. Razão de área foliar.

This study had the objective of assessing the genetic divergence in giant missionary grass (Axonopus jesuiticus x A. scoparius) germplasm based on morphological and agronomic traits. Five accessions were evaluated in the field: V14337, V14403, V14404, V14405 and V14406. Three contrasting groups were formed using the UPGMA clustering method: V14337 and V14404 formed one group, V14403 and V14405 formed another, and V14406 was isolated from the other accessions. The most striking traits for the identification of the accessions were the height of the plant and the change color of the leaf. Only V14406 accession had purplish green leaves. The other four accessions differed with regards to plant height and dry matter production, with superiority of V14337 and V14404 accessions. The high similarity, as assessed by the mean Euclidean distance, suggests that V14337 and V14404 share the same genotype. The genotypic variability among accessions indicates their potential use in breeding programs.

-This study evaluated the morphological development of two populations of tough lovegrass during 120 days of continuous growth (Experiment I), and the regrowth of one population under the combination of cutting height (5 cm and 10 cm) and phenological stage at the first cutting (vegetative and beginning of flowering; Experiment II). In Experiment I, plants were harvested at 30, 60, 90 and 120 days of growth; in Experiment II, three cuttings were carried out at every 30 days, and the plants were harvested four weeks after the previous one. In Experiment I, the populations did not differ for morphological development, showing a linear increase in height and tiller number, and a quadratic trend for root and shoot dry matter (DM).At 120 days of growth, plants presented 10 basal tillers and 80 leaves, strongly compressed at the base and no sign of senescence.In Experiment II, there was no significant cutting height × phenological stage interaction, but cuttings at 5 cm reduced plant size and yield. Cuttings started at the vegetative stage decreased the root (3.06 g DM/plant) and stubble dry matter (1.17 g DM/plant), compared with 6.84 g and 3.99 g DM/plant, respectively, with cuttings started at the flowering stage. Tough lovegrass shows basal architecture, basal bud renovation, leaves densely compressed in the tiller base, high belowground allocation, and elongation of internodes only in reproductive stage. Mechanical control is an alternative method to minimize its growth, especially if it is carried out early in the growing season and at low cutting height.