In general, genetic improvement programs for Eucalyptus seek to increase productivity. Diallelic methods are commonly used in crossbreeding designs, but few studies use this methodology to assess competitive ability. The aim of this study was to estimate the competitive capacity and effects of intra- and inter-genotypic in Eucalyptus spp. clones and identify combinations that support increased productivity. To do this, 12 commercial clones were evaluated in a competitive trial located in Três Lagoas, Mato Grosso do Sul State, Brazil, established in a randomized block design, with three replicates and five plants per plot. Data for the mean annual increment (MAI) obtained at five years of age were assessed using two statistical approaches. Groups were classified according to specific (ability of the two clones to compete each other) and general competitive ability (average ability of a clone to compete with others). There were differences in the genotypes' ability to suffer or exercise competition. The results obtained showed the best combinations resulted in up to 10% increase in productivity. That combined use of diallelic analysis with the statistical approach which allows for the assessment of the effects of intra- and inter-clonal competition, may be useful for Eucalyptus spp. improvement programs, especially in terms of identifying the best combinations for planting when the objective is to obtain gains in crop productivity.

通常，桉树的遗传改良计划力图提高生产率。杂交设计中通常使用拨号方法，但是很少有研究使用这种方法来评估竞争能力。这项研究的目的是评估桉树的竞争能力以及基因型内和基因型间的影响。spp。克隆并识别支持提高生产率的组合。为此，在一项随机试验中评估了12个商业克隆，该实验位于巴西马托格罗索州南特雷格斯拉各斯，采用随机区组设计建立，每个样地有3个重复和5个植物。使用两种统计方法评估了五岁时获得的平均年增量（MAI）数据。根据特异性（两个克隆彼此竞争的能力）和一般竞争能力（克隆平均竞争能力）对组进行分类。基因型受苦或进行竞争的能力存在差异。获得的结果表明，最佳的组合可以使生产率提高多达10％。桉树属。改进计划，特别是在目标是获得作物生产力的前提下，确定最佳种植组合的方面。