Competition between olive nursery trees (Olea europaea L.) and weeds.

O entendimento da interfer?ncia promovida pelas esp?ciesexistentesna comunidadede plantas daninhas doolival esuas densidadesrelativas s?oconsidera??es importantes nomanejo dessas plantas para manter o equil?brio da competi??o, permitindo que o cultivo da oliveira seja beneficiado. A pesquisa foi realizada com o objetivo de avaliar a capacidade competitiva de mudas de oliveira cultivadas com diferentes esp?cies e densidades de plantas daninhas sobre o crescimento vegetativo e os teores de nutrientes. Para avaliar a capacidade de competi??o da oliveira com as plantas daninhas foram conduzidos tr?s experimentos em casa de vegeta??o do Setor de Fruticultura da Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG. No primeiro experimento avaliou-se o crescimento inicial de mudas de duas cultivares de oliveira ?Arbequina? e ?Koroneiki? convivendo com cinco esp?cies de plantas: Bidens pilosa, Brachiaria brizantha, Cenchrus echinatus,Canavalia ensiformis e Lupinus albus, e um tratamento sem conviv?ncia com plantas daninhas por um per?odo de 60 dias. Observou-se que a cultivar Arbequina mostrou-se mais tolerante a interfer?ncia das esp?cies de plantas. B. pilosa, C. ensiformes e L. albus foram as esp?cies com maior potencial de interfer?ncia no crescimento inicial das mudas de oliveira. No segundo, avaliou-se o crescimento de duas cultivares de oliveira, ?Arbequina? e ?Ascolano? cultivadas com quatro esp?cies de plantas competidoras, Amaranthus retroflexus, B. brizantha, B. pilosa, e C. echinatus e as testemunhas, que foram as mudas de oliveiras e as plantas daninhas de cada esp?cie sem competi??o por um per?odo de 90 dias. A competi??o com as plantas daninhas interferiu no crescimento e nos teores de nutrientes de mudas de oliveira. A ?Ascolano? mostrou-se mais tolerante a competi??o com as esp?cies de plantas daninhas. A. retroflexus e B. pilosa foramas esp?cies com maior potencial de competi??o com mudas de oliveira. No terceiro experimento, foi avaliada a conviv?ncia das mudas de oliveira ?Arbequina? e ?Ascolano? com cinco densidades de B.brizantha, zero, uma, duas, tr?s e quatro plantas por vaso por um per?odo de 70 dias. Observou-se que a B. brizantha interferiu negativamente no crescimento vegetativo da oliveira. A cultivar ?Ascolano? apresentou maior capacidade competitiva com todas as densidades de B. brizantha. O aumento da densidade de B. brizantha interferiu no estado nutricional das mudas de oliveira.Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes)Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012.ABSTRACT Understanding of the interference promoted by species existing in weed community of olive groves and their densities are important considerations in management of these plants to maintain the competition balance, allowing the cultivation of olive trees be favored. The research was conducted with the aim of evaluate the competitive ability of olive nursery trees grown with different species and weed densities on vegetative growth and nutrients contents. Three experiments was conducted in a greenhouse of Setor de Fruticultura of Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG to evaluate the competition ability of olive tree with the weeds. The first experiment evaluated the nursery tree growth of two olive cultivars ?Arbequina? and ?Koroneiki? coexisting with five plant species: Bidens pilosa, Brachiaria brizantha, Cenchrus echinatus, Canavalia ensiformis and Lupinus albus and one treatment without coexistence for a period of 60 days. It was observed that the ?Arbequina? cultivar was more tolerant to interference of plant species. B. pilosa, C. ensiformes and L. albus were the species with greater potential for interference on the growth of olive nursery trees. In the second it was evaluated the growth of two olive cultivars, ?Arbequina? and ?Ascolano? planted with four species of competing plants, B. brizantha, A. retroflexus, B. pilosa and C. echinatus and the controls, which were the olive nursery trees and the weeds of each species without competition for a period of 90 days. Competition with weeds affected the growth and nutrients contents of olive nursery trees. ?Ascolano? was more tolerant to the competition with weed species. The species A. retroflexus and B. pilosa were the species with the greatest potential competition with olive nursery tree. In the third experiment was evaluated the relationship between the olive nursery trees ?Arbequina? and ?Ascolano? with four densities of B. brizantha zero, one, two, three and four plants per pot for a period of 70 days. It was observed that B. brizantha affected negatively in vegetative growth of olive nursery trees. The cultivar ?Ascolano? showed greater competitive ability with all densities of B. brizantha. The increased density of B. brizantha affected the nutritional status of olive nursery trees