Morphological development of Paspalum paniculatum L. (Poaceae)

This work aimed to describe the morphological development of Paspalum paniculatum. Individual plants were cultivated in pots and evaluated at seven ages: 31, 58, 93, 123, 134, 144 and 176 days of growth from the emergence. The species showed medium height (50cm), clonal growth, with aerial stems of culm-type, semi-erect, and underground stems of rhizome-type, with reproductive tillers over 100cm in length. The shoot dry matter (DM) at flowering stage was composed by equivalent quantities of culms (C) and leaves (L), in a L:C relationship of 1.5. After 176 days’ growth, the plants had accumulated 23.5g of DM, consisting of roots (29.06%) and rhizomes (15.91%), totaling 44.97% of the DM in the underground part, leaves (21.89%), culms (26.32%) and inflorescences (6.83%). The expressive formation of DM in the underground part suggests resistance to grazing and adverse climatic conditions, in addition to a possible aptitude for revegetation of areas subject to erosion

Manejo de Paspalum dilatatum Poir. biótipo Virasoro. 1. Produção, composição química e persistência

Objetivou-se avaliar o efeito da altura (10 e 20 cm) e do intervalo de cortes (30 e 45 dias) na produção de MS, na composição química e na persistência do capim-melador (Paspalum dilatatum Poir. biótipo Virasoro) em condições de campo. As plantas foram cortadas nove e seis vezes, respectivamente, nos intervalos de corte de 30 e 45 dias, no período de setembro de 2003 a junho de 2004. A produção de MS total não diferiu entre as alturas nem entre os intervalos de corte (média de 2.017 g MS/linha). Houve efeito da interação estação de MS × altura de corte: não houve diferença entre primavera e verão sob cortes a 10 cm (997 g/linha); na altura de corte de 20 cm, a produção obtida no verão (938 g MS/linha) foi maior que a da primavera (761 g MS/linha), enquanto, a 10 cm, os cortes na primavera proporcionaram maior produção (1.030 vs 761 g MS/linha a 20 cm). No outono, a produção de MS foi muito baixa (125 g MS/linha). A produção de folhas aumentou sob cortes freqüentes (30 dias) e intensos (10 cm). Nos cortes feitos a intervalos de 30 dias, houve maior teor de PB (14,7%) e menores teores de FDA (43,8%) e FDN (67,8%). Os cortes não evitaram o florescimento precoce, intenso e contínuo das plantas, que alocaram, em média, 27% da MS em folhas e 68% em caules+inflorescências.This work aimed to evaluate the effect of the cutting height (10 cm and 20 cm) and cutting interval (30 days and 45 days) in the DM production of dallisgrass (Paspalum dilatatum Poir. biótipo Virasoro) cultivated under field conditions. Plants were cut between September/2003 and June/2004, nine and six times, for the 30 d and 45 d cutting interval, respectively. The total DM yield did not differ among treatments, with an average of 2,017 g DM/row. There was a significant interaction between season and cutting height, with no difference observed between summer and spring at 10 cm height (997 g DM/row); at 20 cm cutting height, however, there was a higher yield on the summer (938 g DM/row) than in the spring (761 g DM/row); during the spring, the 10 cm cutting height enhanced the DM production (1,030 g DM/row) in relation to the 20 cm cutting height (761 g DM/row). The fall DM production was low (125 g DM/row). The leaf yield increased under frequent (30 days) and intense (10 cm) cutting. The highest CP concentration (14.7%) and the lower ADF (43.8%) and NDF (67.8%) concentrations were obtained under the frequency of 30 days. The cutting management did not affect the early, continuous, and intense flowering of the plants, which allocated an average of 27% of DM to the leaves and 68% to the stems + inflorescences

Comportamento de leguminosas (Adesmia, Lotus, Trifolium) em mistura com festuca Response of legumes (Adesmia, Lotus, Trifolium) in mixture with tall fescue

A introdução de leguminosas hibernais é uma das práticas mais importantes para incrementar a quantidade, a qualidade e a sustentabilidade de pastagens perenes no Sul do Brasil. Durante os anos de 2000 e 2001, foi avaliado o comportamento de seis leguminosas temperadas (Adesmia latifolia - nativa, Lotus corniculatus, L. subbiflorus, L. uliginosus e Trifolium repens - cv. Yi e Regal), em mistura com festuca (Festuca arundinacea). Entre a semeadura e o último corte decorreram 475 dias, sendo realizados seis cortes: no outono-inverno/2000, foi feito um corte; na primavera-verão, três e, no outono-inverno/2001, dois cortes. Os intervalos entre cortes variaram entre 43 a 91 dias, sendo menores na estação estival. No total do período experimental obtiveram-se, na média das misturas, 15.038 kg/ha de MS, sendo que, na primavera-verão foram produzidos cerca de 54% desse total, com taxa de crescimento média de 46 kg/ha/dia de MS. Nos meses de outono-inverno de 2000 e 2001, foram obtidas taxas de 22 e 24 kg/ha/dia de MS. O cornichão e o trevo-branco cv. Yi foram as leguminosas mais produtivas, sendo que a primeira destacou-se na primavera-verão (3.500 kg/ha de MS) e a última participou com 86,3% na mistura no outono-inverno/2001, com 2.300 kg/ha de MS. As misturas contendo essas leguminosas apresentaram a menor quantidade de invasoras e produziram, respectivamente, 13.663 e 11.184 kg/ha de MS, sendo 82 e 71% desses totais compostos das leguminosas, festuca e azevém. A. latifolia não teve bom estabelecimento e sua participação foi de 0,84% no primeiro corte. L. subbiflorus teve uma boa participação no primeiro ano (37%), mas desapareceu no segundo ano. L. uliginosus mostrou boa persistência, produzindo 1.400 kg/ha de MS no outono/2001.Overseeding temperate legumes is one of the most practices to increase the quantity, quality and sustainability of perennial pastures in Southern Brazil. During the years of 2000 and 2001 the response of six temperate legumes (Adesmia latifolia (wild), Lotus corniculatus, L. subbiflorus, L. uliginosus and Trifolium repens cv. Yi and cv. Regal) was evaluated in mixture with tall fescue (Festuca arundinacea). There was a period of 475 days between sowing date and the last cut and six cuts were made; on the autumn-winter/2000 only one cut was made, on the spring-summer, three cuts and on the autumn-winter/2001, two cuts. The intervals between cuts ranged between 43 and 91 days, being reduced in the warm season. During the total assay period, the average of the mixtures yielded 15038 kg/ha of DM; in the warm season 54% of this total was produced, with an average growth rate of 46 kg/ha/day of DM. In the cold season of 2000 and 2001 this rate was of 22 and 24 kg/ha/day of DM. The birdsfoot trefoil and white clover cv. Yi were the most productive legumes; the former was the best in the warm season (3500 kg/ha of DM) and the last participated with 86,3% in the mixture in the autumn-winter/2001, with 2300 kg/ha/day of DM. The mixtures containing these legumes presented the smallest quantity of weeds and produced 13663 and 11,184 kg/ha of DM respectively, being 82% and 71% of these totals composed of legumes, fescue and ryegrass. A. latifolia did not have a good establishment and its contribution was only 0,84% in the first cut. The L. subbiflorus had a good establishment on the first year, but it disappeared from the mixture in the second year. L. uliginosus had a good establishment and persistence producing up to 1400 kg/ha of DM in the autumn/2001