Relative accumulation of nutrients by the commercial clone - I144 of eucalyptus in competition with grasses and tolerance to indaziflam

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.?rea de concentra??o: Produ??o Vegetal.A cultura do eucalipto ? sens?vel ? competi??o de plantas daninhas durante o per?odo inicial de crescimento. O controle qu?mico dessas plantas com herbicidas pr?-emergentes ? recomendado. Embora os estudos relatem a efici?ncia de herbicidas pr?-emergentes no controle dessas plantas, pouco se sabe do efeito em plantas de eucalipto, quando expostas a solo contaminado. Este trabalho teve como objetivos avaliar os efeitos da competi??o das plantas daninhas Urochloa brizantha, Urochloa decumbens e Megathyrsus maximus no crescimento, conte?do relativo de nutrientes e efici?ncia nutricional do h?brido clonal de eucalipto e avaliar as respostas fisiol?gicas e de crescimento dessa esp?cie em solo contaminado com indaziflam, bem como o potencial de lixivia??o desse herbicida por meio de bioensaio. Dois experimentos foram realizados em casa de vegeta??o. O primeiro foi conduzido em delineamento inteiramente casualizado, com sete tratamentos e dez repeti??es. Os tratamentos foram compostos de plantas de eucalipto em competi??o com tr?s gram?neas e tratamento controle de plantas de eucalipto e das plantas daninhas. A altura, di?metro do caule, n?mero de folhas, ?rea foliar, conte?do relativo de nutrientes nas folhas e efici?ncia de absor??o, transporte e utiliza??o de N, P e K do h?brido clonal de eucalipto foram avaliados aos 110 dias ap?s plantio. Urochloa decumbens foi a esp?cie com maior capacidade competitiva, pois reduziu de forma consider?vel o conte?do relativo de nutrientes e a efici?ncia nutricional da cultura. O segundo experimento foi em delineamento em blocos casualizados com quatro repeti??es. Os tratamentos resultaram de fatorial 3 x 5. O primeiro fator correspondeu ao controle (solo sem herbicida) e solo com o herbicida indaziflam, em duas doses correspondentes a 25% e 50% do produto comercial (150 g ha-?). O segundo fator foi composto pelas profundidades: 0-10, 10-20, 20-30, 30-40 e 40-50 cm. Clorofila a e b, fluoresc?ncia da clorofila, intoxica??o, altura, mat?ria seca de folha, caule e raiz e o potencial de lixivia??o do herbicida no perfil do solo foram avaliados. O indaziflam apresentou potencial de lixivia??o at? profundidade de 30 cm na dose de 37,5 e 75 g ha-?.Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Celulose Nipo-Brasileira S/A (CENIBRA)Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2020.Eucalyptus cultivation is sensitive to weed competition during the initial growth period. Chemical control of these plants with pre-emergent herbicides is recommended. Although studies report the efficiency of pre-emergent herbicides in controlling these plants, little is known about the effect on eucalyptus plants when exposed to contaminated soil. This work aimed to evaluate the effects of the competition of the weeds Urochloa brizantha, Urochloa decumbens and Megathyrsus maximus on growth, relative accumulation of nutrients and nutritional efficiency of the clonal eucalyptus hybrid and to evaluate the physiological and growth responses of this species in soil contaminated with indaziflam, as well as the potential for leaching of this herbicide through bioassay. Two experiments were carried out in a greenhouse. The first was conducted in a completely randomized design, with seven treatments and ten repetitions. The treatments were composed of eucalyptus plants in competition with three grasses and control treatment of eucalyptus plants and weeds. The height, stem diameter, number of leaves, leaf area, relative content of nutrients in the leaves and absorption efficiency, transport and use of N, P and K of the clonal eucalyptus hybrid were evaluated at 110 days after planting. Urochloa decumbens was the species with the most significant competitive capacity, as it significantly reduced the relative content of nutrients and the nutritional efficiency of the crop. The second experiment was in a randomized block design with four replications. The treatments resulted from a 3 x 5 factorial. The first factor corresponded to the control (soil without herbicide) and soil with the herbicide indaziflam, in two doses corresponding to 25% and 50% of the commercial product (150 g ha-?). The second factor was composed of the depths: 0-10, 10-20, 20-30, 30-40 and 40-50 cm. Chlorophyll a and b, chlorophyll fluorescence, intoxication, height, dry leaf matter, stem and root, and the herbicide leaching potential in the soil profile were evaluated. Indaziflam showed leaching potential up to a depth of 30 cm at a dose of 37.5 and 75 g ha-?