Initial root interference of Urochloa brizantha in maize and bean evaluated by means of rhizotrons

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-04-03T20:28:05Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ana_flavia_freitas.pdf: 1136034 bytes, checksum: 965afc88d55a61d59101bffaca9ad367 (MD5)Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-04-24T16:56:16Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ana_flavia_freitas.pdf: 1136034 bytes, checksum: 965afc88d55a61d59101bffaca9ad367 (MD5)Made available in DSpace on 2017-04-24T16:56:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ana_flavia_freitas.pdf: 1136034 bytes, checksum: 965afc88d55a61d59101bffaca9ad367 (MD5) Previous issue date: 2016Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq.)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM)Consider?vel redu??o na produtividade de culturas e consequente perda financeira resultam da competi??o com plantas daninhas. Essas perdas s?o muito estudadas e disponibilizadas na literatura, por meio da rela??o dos per?odos de controle. Contudo, mesmo ap?s amplos estudos sobre per?odos, as divulga??es recentes sobre a teoria do ?inicialismo?, pouco se sabe sobre o momento inicial da interfer?ncia radicular entre plantas, principalmente devido a dificuldades na visualiza??o dos eventos iniciais. Dessa forma, objetivou-se estimar a partir da semeadura em rizotrons, os primeiros sinais que levariam ? interfer?ncia entre sistemas radiculares. Foram realizados dois experimentos em casa de vegeta??o: No primeiro, os tratamentos foram arranjados em esquema fatorial 3x2, sendo, 3 esquemas de cultivo do feijoeiro (solteiro, com uma e com duas plantas de braqui?ria) com e sem aduba??o fosfatada, conduzido em um delineamento inteiramente casualizado com 4 repeti??es. Ap?s a semeadura das esp?cies, os resultados da visualiza??o foram registrados a cada 12 horas, por meio de fotografias do desenvolvimento do sistema radicular. O sistema de ra?zes do feijoeiro apresentou maior comprimento e ?rea radicular quando em defici?ncia de f?sforo e presen?a de duas braqui?rias. O segundo experimento foi arranjado em esquema fatorial 2x2, sendo cultivo do milho solteiro ou com uma planta de braqui?ria e pela submiss?o ou n?o do substrato ? esteriliza??o, conduzido em um delineamento inteiramente casualizado com 4 repeti??es. Foi observado maior comprimento radicular das pl?ntulas de milho, quando em presen?a da braqui?ria, por?m, sem efeito quanto ? esteriliza??o do substrato. Verificaram-se varia??es no ac?mulo de N, Mn, K, Ca e P, al?m da redu??o em altura, n?mero de folhas e mat?ria seca do milho em fun??o da esteriliza??o do substrato. As culturas como feij?o e milho s?o influenciadas quando est?o submetidas ? interfer?ncia da Urochloa brizantha antes da emerg?ncia.Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.Considerable reduction in crop productivity and consequent financial loss result from competition with weeds. These losses are widely studied and made available in the literature by listing the control periods. However, even after extensive studies on periods and the recent disclosures about the ?initialism? theory, little is known about the initial moment of root interference between plants, especially due to difficulties in the visualization of the initial events. In this sense, the objective was to estimate, sowing in a rhyzotron, the first signals that would take to interference between root systems. Two experiments were conducted in a greenhouse: In the first, treatments were arranged in a 3x2 factorial arrangement, with three beans cultivation schemes (single, with one and with two Brachiaria plants) with and without P fertilization, conducted in a completely randomized design, with four replications. After sowing the species, visualization results were recorded every 12 hours by means of photographs of the development of the root system. The bean root system showed greater length and root area when under phosphorus deficiency and in the presence of two Brachiaria plants. The second experiment was arranged in a 2x2 factorial design, with cultivation of maize single or with one Brachiaria plant, and by the submission or not of the substrate to sterilization, in a completely randomized design, with four replications. After sowing the species, visualization results were recorded every 12 hours by means of photographs of the development of the root system. It was observed higher root length in maize seedlings when in the presence of Brachiaria, however, no effect of substrate sterilization. There were variations in the accumulation of N, Mn, K, Ca and P, and decreases in height, number of leaves and maize dry matter as a function of the substrate sterilization. Crops as bean and maize are influenced when subjected to interference of Urochloa brizantha before emergency