Estratégias de manejo da desfolha para a reforma da estrutura do dossel de pasto perene de clima tropical

• Ano de defesa: 2021
• Autor(a) principal: Zatta, Angélica Caroline
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Tecnológica Federal do Paraná; Pato Branco; Brasil; Programa de Pós-Graduação em Agronomia; UTFPR
• Palavras-chave em Português: Plantas forrageiras; Pastagens; Desfolhamento; Forragem; Forage plants; Pastures; Defoliation; Forage; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA; Agronomia
• Link de acesso: http://repositorio.utfpr.edu.br/jspui/handle/1/24910

Pasture management aims to reconcile maximum forage production with theefficiency of its use. However, the plants are affected by disturbances created bydefoliation events, whose frequency and severity are dependent on the grazingsystem. What they reflect in the productive and qualitative capacity of the pasture. Inthis way, the present study proposes to evaluate the effect of different defoliationmanagements as a tool for the reform of the pasture canopy structure of warm-season perennial pastures. The experiment was carried out in the UTFPRExperimental Area (Pato Branco), in randomized block design, with threereplications. The treatments consisted of five defoliation managements, with two IL(95 and 98%) and two defoliation severities (50 and> 50%) for defoliation.Treatment95-50 was considered the ideal management; 98-R1, low frequency and highseverity; 98I-R1 and 98F-R1, managements that simulated canopy corrections in thefinal and / or end of the pasture cycle; and 98-50, handling pasture "past" butmaintaining a severity of 50%.Characters that made it possible to determine thecharacteristics of growth, productivity and quality of pasture through the productiondynamics of the plant over time, in addition to the canopy characters. The data weresubjected to analysis of variance, and those with significance, compared by theTukey means test (P> 0.05).In general, for total dry matter production, 98I-R1 wassuperior only to 98-R1, with a difference of 2000 Kg MS ha-1. For morphologicalcomposition, treatment 95-50 showed higher% blades and lower% of stalk in theharvested stratum, and in the remainder the same follow-up, which enabled avigorous regrowth and a greater number of defoliation than 98-R1.As a result ofthese differences in the morphological composition harvested between treatments,the nutritional value in pastures that received a greater severity of defoliation andexceeded the pre-cut height (98-R1) generated a canopy less favorable to obtaininga quality diet. It is concluded that pastures that pass the maximum harvest height(95% IL) can be reduced to the original residue, or managed with a new and higherresidual height, without compromising primary productivity, but occasionally implyingchemical restrictions and structural.