Detalhes bibliográficos
| Ano de defesa: |
2019 |
| Autor(a) principal: |
RIBEIRO, Robson Elpidio Pereira
 |
| Orientador(a): |
MELLO, Alexandre Carneiro Leão de |
| Banca de defesa: |
SANTOS, Antônio Clementino dos,
SANTOS, Mércia Virginia Ferreira dos,
VOLTOLINI, Tadeu Vinhas,
SILVA, Valdson José da |
| Tipo de documento: |
Tese
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Federal Rural de Pernambuco
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Zootecnia
|
| Departamento: |
Departamento de Zootecnia
|
| País: |
Brasil
|
| Palavras-chave em Português: |
|
| Área do conhecimento CNPq: |
|
| Link de acesso: |
http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8088
|
Resumo: |
The objective of this study was to evaluate the effect of plant size and irrigation on the establishment, morphological and productive aspects of genotypes of Pennisetum purpureum Schum., under cut, in the Southern Agreste of Pernambuco. The experimental design in the three chapters was randomized in blocks. In the first chapter the treatments studied were the genotypes (IRI 381 and Elefante B, of high size and Taiwan A-146 2.37 and Mott, of low size) with evaluations of aspects related to the establishment realized during 90 days after the planting. The time factor was analyzed as repeated measures and the interaction of this time factor with the treatments (genotypes) was verified. In the second and third chapters the treatments were arranged in subdivided plots, the main plots being the presence/absence of irrigation, and the subplots, the genotypes (IRI 381 and Elefante B, tall and Taiwan A-146 2.37 and Mott, from low load). Morphological and productive aspects were studied in genotypes in successive crops every 60 days. Eleven crops were harvested, six in the dry season and five in the rainy season, and the data analyzed by season (rainy and dry). The time factor was analyzed as repeated measurements and the interaction with the genotypes, irrigation and seasons was verified. It was also analyzed the interactions with the size factor, irrigation and seasons and in this case the effect of the genotypes was not considered. In the establishment evaluations, the dynamics of tillering and morphological characterization of tillers at 20, 41, 55, 75 and 90 days after planting were analyzed, total non-structural carbohydrates contents and shoots at 20, 40, 60 and 90 days after planting. After the establishment phase, uniformity cut was performed. Morphological characteristics were evaluated: percentage of leaves and stems, plant height, number of nodes, length of nodes, stem diameter, apical meristem height, number of green leaves per tiller, number of live tiller.m-1 linear, number of dead tiller.m-1 linear, light interception (LI) and leaf area index (LAI)], as well as productive aspects [dry matter (DM) content of whole plant, leaf and stem; efficiency of water use; total forage accumulations, per year (2017 and 2018) and by harvest, forage accumulation rate, forage density and leaf/stem ratio]. At the establishment, the sprouting percentage of the high - sized genotypes (Elefante B and IRI 381) was higher than those of low size (Mott and Taiwan A - 146 2.37), both at 20 and 90 days after planting, with mean values of 83 and 64% in the first evaluation (20 days after planting), reaching 98 and 85%, at 90 days after planting, respectively. The number of tillers was 43 and 36 linear tiller.m-1, for Taiwan A-146 2.37 and Mott, respectively, and 29 tiller.m-1 for Elephant B and IRI 381. Non-structural total carbohydrates concentrations were highest in the base, due to the greater stem diameter, that is, this allows a higher concentration of soluble sugars. Regarding the morphological characteristics during the harvest, Elephant B and IRI 381 obtained higher average heights (1.65 m), followed by Taiwan A-146 2.37 and Mott, with the lowest average height (0.80 m). Irrigation had a significant effect on most responses of the variables, either alone or in the interactions with other factors, confirming the positive effect of water on the development of morphological characteristics, especially in the dry season. For accumulation of total fodder it was verified difference between the genotypes. IRI 381 obtained a total forage accumulation of 69,906 kg of MS.ha-1 in the two years evaluated, with the majority of 24,667 kg of MS.ha-1 occurring during the rainy season with irrigation, while Mott obtained lower accumulation (15,175.4 kg of MS.ha-1). Considering the effect of irrigation on the annual forage accumulation, the additional yield of the irrigated to the non irrigated was 60 and 59%, in 2017 and 2018, respectively. The results of this work confirm the potential of using irrigated weeds with the four evaluated genotypes (Elefante B, IRI 381, Mott and Taiwan A-146 2.37), thus being a viable alternative for forage production, even though there were morphological differences between the genotypes . There was clone and irrigation effect for the morphological characteristics of the plants in the two seasons of the year. The use of irrigation made possible a greater accumulation of forage over the years, in elephant grass cut and carry, independent of genotypes and plant sizes. The high sized genotypes and Taiwan A-146 2.37 (low-sized) presented higher averages in most of the productive variables when compared to the low-sized ones. Mott presented better forage density and L/S ratio. |
