O presente trabalho foi realizado com apoio da Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - Brasil (CAPES) - C?digo de Financiamento 001. Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2020-09-28T17:55:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) priscila_junia_rodrigues_cruz.pdf: 1178262 bytes, checksum: 931434757217743c2b36efbb99996afa (MD5) Approved for entry into archive by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2020-09-28T17:57:16Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) priscila_junia_rodrigues_cruz.pdf: 1178262 bytes, checksum: 931434757217743c2b36efbb99996afa (MD5) Made available in DSpace on 2020-09-28T17:57:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) priscila_junia_rodrigues_cruz.pdf: 1178262 bytes, checksum: 931434757217743c2b36efbb99996afa (MD5) Previous issue date: 2019 Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) O presente estudo foi proposto com o objetivo de avaliar o efeito do sombreamento artificial (0, 30, 45 e 75%) nas caracter?sticas morfog?nicas e estruturais, na produ??o de massa seca total, porcentagem de componentes morfol?gicos, altura do dossel e fisiologia de tr?s gram?neas (Brachiaria spp. cv. Mavuno, Panicum maximum cv. Zuri, P. spp. cv. Tamani) e duas leguminosas forrageiras (Macrotyloma axillare cv. Java e Arachis pintoi cv. Amarillo), durante duas esta??es do ano (outono/inverno e primavera/ver?o) em Diamantina-MG. As forrageiras foram avaliadas no per?odo de maio de 2017 a maio de 2018. Foram marcados seis perfilhos ou ramifica??es em cada sub-parcela e esses foram avaliados duas vezes por semana durante um ciclo de avalia??o em cada esta??o do ano, at? atingir 95% de IL. A cada avalia??o foram mensurados o comprimento do pseudocolmo ou caule, comprimento da l?mina foliar, registro de novas folhas surgidas por perfilhos, e verifica??o das l?minas foliares expandidas e senescentes. Foram determinadas a taxa de aparecimento foliar (TApF), taxa de alongamento foliar (TAlF), taxa de alongamento do pseudocolmo (TAlC), taxa de alongamento do pec?olo para as leguminosas, taxa de senesc?ncia foliar (TSF), filocrono (FILOC), n?mero de folhas vivas (NFV), tamanho final da l?mina foliar (CFLF), tamanho final do pseudocolmo (TFC), dura??o da vida da folha (DVF), ?ndice de ?rea foliar (IAF), dura??o m?dia do ciclo (DMC) e n?mero total de ciclos (NTC). No dia do corte foi determinada a altura do dossel. Foram realizadas leituras da rela??o vermelho:vermelho distante (V:Ve), teores de clorofila a e b, taxa fotossint?tica (A), taxa respirat?ria (E), condut?ncia estom?tica (gs), temperatura da folha (TFol) e efici?ncia do uso da ?gua (EUA). Amostras foram coletadas para determina??o da composi??o morfol?gica e perfilhamento. O capim-mavuno manteve constante o IAF nos diferentes sombreamentos, sofrendo efeito apenas da esta??o do ano para as caracter?sticas morfog?nicas. Plantas de BRZ Zuri apresentaram redu??o no fluxo de tecidos durante a esta??o outono/inverno, pronunciando o efeito da redu??o da radia??o e aumentando a DMC. O BRS Tamani apresentou grande capacidade de adapta??o aos n?veis de sombreamento e pouca influ?ncia da esta??o do ano. A redu??o da temperatura e radia??o durante a esta??o outono/inverno ocasionou a morte da leguminosa macrotiloma independente do sombreamento. O amendoim-forrageiro foi influenciado pela esta??o do ano, apresentando grande adapta??o a ambientes sombreados. O sombreamento artificial n?o alterou a V:Ve acima do dossel forrageiro. As gram?neas e o amendoim-forrageiro apresentaram altura de dossel crescente com o aumento do sombreamento, a macrotiloma n?o exibiu tal comportamento. As forrageiras avaliadas apresentaram maior porcentagem de l?minas foliares com o aumento do sombreamento, com exce??o do BRS Tamani, que n?o apresentou altera??o nessa vari?vel. As gram?neas apresentaram A, E e gs reduzidas ? medida que o sombreamento se intensifica. Comportamento oposto ocorreu para o amendoim-forrageiro e maiores A, E e gs foram observadas sob 0 e 45% para a macrotiloma, evidenciando maior adapta??o dessa leguminosa a esses sombreamentos. Houve aumento nos teores de clorofila b e da TFol com o aumento do sombreamento em todas as forrageiras avaliadas no presente estudo. O capim-mavuno pode ser manejado em sistemas com at? 30% de sombreamento, sem perdas na produ??o. As gram?neas do g?nero Panicum apresentaram grande adapta??o aos n?veis de sombra, podendo ser implantadas em sistemas adensados. A maior produ??o da macrotiloma sob 45% de sombreamento est? relacionada com a maior efici?ncia fotossint?tica da cultivar nessa condi??o. O amendoim-forrageiro apresentou grande adapta??o fisiol?gica aos sombreamentos leves e moderados, apresentando perda de produ??o em sombreamento intenso. Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2019. The aim of this study was to evaluate the effect of artificial shading (0, 30, 45 and 75%) on morphogenic and structural characteristics, total dry mass production, percentage of morphological components, canopy height and physiology of three (Brachiaria spp., Mavuno, Panicum maximum cv. Zuri, P. spp. cv. Tamani) and two forage legumes (Macrotyloma axillare cv.Java, and Arachis pintoi cv Amarillo), during two seasons of the year (autumn/winter and spring/summer) in Diamantina-MG. The forages were evaluated from May 2017 to May 2018. Six tillers or branches were marked in each subplot and evaluated twice a week during an evaluation cycle in each season of the year, until reaching 95% of IL. The length of the pseudo stem or stem, length of the leaf blade, registration of new leaves by tillers, and verification of the expanded and senescent leaf blades were measured at each evaluation. Foliar leaf rate (FLR), foliar elongation rate (FER), pseudo stem elongation rate (pSER), petiole elongation rate for legumes, foliar senescence (FS), phyllochron rate (FILOC) number of live leaves (NLF), leaf blade final size (LBFS), final pseudo stem size (FpSS), leaf life span (LLS), leaf area index (LAI), mean cycle duration (CD) and total number of cycles (TNC). On the day of the cut the height of the canopy was determined. The red ratio (V:Ve), chlorophyll a and b, photosynthetic rate (A), respiratory rate (E), stomatal conductance (gs), leaf temperature (TFol) and water use efficiency (USA). Samples were collected for determination of morphological composition and tillering. The mavuno grass kept the LAI constant in the different shades, having only effect of the season of the year for the morphogenic characteristics. BRZ Zuri plants showed reduction in tissue flow during the fall/winter season, pronouncing the effect of radiation reduction and increasing CD. The BRS Tamani showed great ability to adapt to the shading levels and little influence of the season. The reduction of temperature and radiation during the fall/winter season caused the death of legume perennial horsegram independent of shading. The forage peanut was influenced by the season, presenting great adaptation to shaded environments. Artificial shading did not change V: Ve above the forage canopy. Grasses and forage peanuts presented increasing canopy height with increasing shading, the perennial horsegram showed no such behavior. The evaluated forages presented a higher percentage of leaf blades with the increase of the shading, except for the BRS Tamani, that did not present alteration in this variable. Grasses showed reduced A, E and gs as shading intensifies. Opposite behavior occurred for the forage peanut and higher A, E and gs were observed under 0 and 45% for the perennial horsegram, evidencing a greater adaptation of this legume to these shadings. There was an increase in the levels of chlorophyll b and TFol with increasing shading in all forages evaluated in the present study. The mavuno grass can be managed in systems with up to 30% shading, without losses in production. The grasses of the genus Panicum showed great adaptation to the shade levels, being able to be implanted in densified systems. The higher production of the perennial horsegram under 45% shading is related to the greater photosynthetic efficiency of the cultivar in this condition. The forage peanut presented a great physiological adaptation to light and moderate shade, presenting loss of production in intense shading.