Data/hora: 24/05/2024 02:46:33

Biblioteca(s): | Embrapa Amazônia Oriental.
Data corrente: | 12/03/1998
Data da última atualização: | 14/02/2017
Autoria: | JANK, L.
Título: | Study of factors affecting seed produciton in pensacola and argentine bahiagrass (Paspalum notatum).
Ano de publicação: | 1982
Fonte/Imprenta: | Gainesville: University of Florida, 1982.
Páginas: | 96 p.
Idioma: | Inglês
Notas: | M.Sc. Thesis.
Conteúdo: | Bahiagrass, Paspalum notatum flugge, is the most important forage species in the state of Florida. Little information is available on seed production, which presents problems of low yields and low quality. To obtain this information, two experiments were conducted at the beef research unit, Gainesville, Florida, on 'Pensacola'and 'Argentine' baniagrass. The effects of seven fertilizer combinations, four levels of nitrogen (0, 100, 200, and 400 kg ha-1) with fixed amonust of 100 kg ha-1 of phosphorus and potassium, and three combinations of 100 kg ha-1 of nitrogen with variable amounts of 0 and 100 kg ha-1 of phosphorus and potassium, were evaluated and without vertical mowing for seed yields and quality of each cultivar. The design was a randomized complete block with three replications. Seed head numbers were a good measure of seed production, being highly correlated with seed yields. Nitrogen was the most impotant element in increasing seed head numbers and yield. Especially 'Argentine' bahiagrass seed production was very limited by nitrogen. The level which resulted in highest yields was 200 kg ha-1 when harvested at optium time. Linear responses were obtained at this time up this level. Otherwise, additions of above 100 kg ha -1 would not be advantageous. The highest N level depressed seed yield in 'Pensacola' bahiagrass. Phosphorus and potassium had negligible effects upon seed yields in both cultivares, but seed yields were highen nitrogen was added to the basic phosphorus and potash applications. Potassium was more advantageous for seed production than pjosphorus. Verticut depressed seed yields and head numbers, and extended the peak production period. Germination percentages were not affected by N. Values were high, 70 to 93% in 'Pensacola' and 63 to 89% in 'Argentine' bahiagrass. Germination percentages were higher in ealier harvests. Purity percentages were high in 'Pensacola'bahiagrass (83 to 93%) decreasing linearly with each harvest. They were low in 'Argentine'bahiagrass (45 to 64%) and cosntant for all the harvests. Nitrogen did not affect putitu percentages. Peak seed yields in 'Pensacola'cultivar ocurred mid-july; the optium harvest dates based upon initial head emergence or peak anthesis could not be determined. Peak seed yields in 'Argentine'bahiagrass occurred late-august, early september, that is 6 to 8 weeks after initial head emergence and 28 to 42 days after peak anthesis. High N levels advanced initial head emergence but not anthesis. Peak seed quality in this cultivar could not be determined since only seeds from two harvests were analyzed. However, it occurred at least two weeks prior to peak seed yields.
Palavras-Chave: | Cultural methods; Feed grasses; Feed production; Produção de semente; Qualidade da semente; Quality.
Thesagro: | Gramínea Forrageira; Npk; Paspalum Notatum; Pratica Cultural; Produtividade.
Thesaurus Nal: | yields.
Categoria do assunto: | --
Registro original: | Embrapa Amazônia Oriental (CPATU)
Exemplares: | CPATU - (31253-1) - ADD - TS - PP - 1982/034 - JAN - 1982/034 - DIS