Weed control in two clones of Eucalyptus 7 urograndis In Amap\ue1

Objetivou-se analisar o crescimento inicial de dois clones do h\uedbrido Eucalyptus 7 urograndis em diferentes sistemas de manejo da matocompeti\ue7\ue3o, ao longo do tempo, no ano de implanta\ue7\ue3o em \ue1reas amapaenses. O trabalho foi desenvolvido na Amap\ue1 Florestal e Celulose S.A. (AMCEL), no per\uedodo de setembro de 2006 a novembro de 2007, em duas \ue1reas experimentais localizadas no munic\uedpio de Itaubal, AP (0\ub042\u2019N; 50\ub048\u2019W) onde foram plantados de forma mecanizada dois diferentes clones do h\uedbrido Eucalyptus 7 urograndis, caracterizando um clone por talh\ue3o (H3911 e H3243). A limpeza das \ue1reas foi realizada por meio de aplica\ue7\ue3o do herbicida glifosato. O experimento foi alocado em delineamento de medidas repetidas, com os arranjos: Dois clones \u2013 H3911 e H3243; seis tratamentos - T1: sem limpeza; T2: limpeza total com herbicida; T3: limpeza com herbicida em duas faixas de 50cm na linha de plantio; T4: limpeza com herbicida em duas faixas de 75cm na linha de plantio; T5: limpeza com herbicida em duas faixas de 100 cm na linha de plantio e, T6: coroamento com 75 cm de raio por meio de herbicida; com quatro repeti\ue7\uf5es. Foram mensuradas durante os primeiros quatro meses de avalia\ue7\ue3o apenas as alturas das plantas. A partir do quinto m\ueas, al\ue9m das alturas foram mensurados os di\ue2metros a 1,30 m do solo (DAP). Foi realizado o teste de esfericidade de Mauchly e testadas \ue0s hip\uf3teses de nulidade das intera\ue7\uf5es tempo x clone e tempo x clone x tipos de limpezas, e quando verificadas diferen\ue7as significativas (p < 0,05), as m\ue9dias foram comparadas por meio do teste de Tukey. Em rela\ue7\ue3o ao clone H3911, o tratamento com maior T5 e o de limpeza total, as alturas mostraram-se estatisticamente semelhantes, o que n\ue3o ocorreu com os demais tipos de limpezas. Quanto aos DAP\u2019s das plantas do clone H3911, foi observado crescimento com repostas similares, no entanto com diferentes velocidades de crescimento durante o per\uedodo de avalia\ue7\ue3o, com T1 e T6 demonstrando maior sensibilidade \ue0 competi\ue7\ue3o. As alturas das plantas do clone H3243 mantiveram-se estatisticamente semelhantes no final do experimento, no entanto, quanto aos DAP\u2019s, foi observado que as plantas do T1, apesar de, no primeiro m\ueas de avalia\ue7\ue3o, possuir o valor m\ue9dio de DAP (2,3cm) estatisticamente superior aos demais tratamentos de limpezas, estes foram mais sens\uedveis \ue0 presen\ue7a e efeito da matocompeti\ue7\ue3o. O crescimento das plantas do tratamento com Limpeza Total se destacou dos demais ao longo de um ano de avalia\ue7\ue3o, para os dois clones testados.This study aimed to analyze the initial growth of two clones of the hybrid Eucalyptus 7 urograndis in different weed management systems, during the year of implantation, in the Amap\ue1 area. The study was developed in Amap\ue1 Florestal Celulose S.A. (AMCEL), from September/2006 until November/2007, with two experimental areas located in Itaubal, AP (0\ub042\u2019N; 50\ub0450\ub048\u2019W). Two clones of the hybrid Eucalyptus 7 urograndis (H3911 and H3243) were planted by mechanized form, with one clone per stand. The areas were cleaned using an application of glyphosate. A repeated measure model was used. Treatments consisted of the two clones and six silvicultural treatments with four replicates (T1: without cleaning; T2: total cleaning; T3: cleaning in two bands of 50cm at the plantation line; T4: cleaning in two bands of 75cm at the plantation line; T5: cleaning in two bands of 100cm at the plantation line; and T6: circle cleaning with 75cm of ray). In the beginning of the evaluation, only plants height were measured. From the fifth month on, the diameter, at 1.30m (DBH), was also measured. The Mauchly sphericity test was carried out and hypotheses of nullity were tested for interactions time x clone and time x clone x types of cleanness. Differences among means were compared by Tukey test (p < 0.05). For clone H3911, the treatment T5 and Total Cleaning showed statistically similar heights, which did not occur with the other treatments. For the DBH of clone H3911 plants, growth was similar, though with different rates of growth during the evaluation period, where T1 and T6 showed greater sensitivity to competition. The heights of clone H3243 plants remained statistically similar at the end of the experiment, however, for DAP, it was observed that plants from T1 were more sensitive to the presence and effect of weeds, athough they had a mean DBH statistically superior to other treatments in the first month of evaluation.The growth of plants from the Total Cleaning treatment was superior in comparison to the other treatments over a year of assessment for both clones tested