Abstract In many cases, traditional analysis of breeding trials based on analysis of variance (ANOVA) do not allow a suitable genetic evaluation. Alternatively, mixed model-based approaches create the possibility of dealing with unbalanced data and modeling spatial trends. The aims of this study were to compare the goodness-of-fit of the model and the genotype ranking through different residual modeling approaches and to select the best performing tropical wheat genotypes based on the best-fitting model. A panel of tropical wheat genotypes was evaluated in three field trials conducted between 2020 and 2021 for grain yield. Linear mixed model analyses were used on the data to estimate the genetic parameters and to predict the genotypic values in analyses of single- and multi-environment trials. Accounting for spatial trends in the analyses of single- and multi-environment trials provides better outcomes than the compound symmetry model does. cases ANOVA (ANOVA evaluation Alternatively modelbased goodnessoffit goodness fit bestfitting fitting 202 yield single multienvironment multi environment does 20 2

Abstract Species of the genus Cynodon are among the most cultivated forage crops in the world due to their high yield and nutritional quality, and its use in cattle feeding has been associated with gains in animal weight and increased milk production. The objective of this study was to model covariance structures in Cynodon spp. clones and study the changes in ranking of the selected genotypes, since it is believed that affects the ranking of genotypes. A total of 202 genotypes were evaluated in an experiment conducted in an augmented block design with four replications and four harvests. The genotypes were assessed for plant height, green weight, percentage of dry matter, and plant vigor. Nineteen repeated measures models with different covariance structures were tested. The best-fitted model adopts the CORH covariance structure for the genetic effects. Correct modeling of the covariance structure affected the ranking of genotypes in all variables evaluated. quality production spp 20 harvests height matter vigor tested bestfitted best fitted effects 2

Resumo O sistema agroflorestal (SAF) à base de cupuaçu (Theobroma grandiflorum) pode ser utilizado para a recomposição da vegetação no entorno de nascentes e de matas ciliares de mananciais (rios, córregos, lagos, etc.), sujeitos a inundações constantes. Os objetivos deste estudo foram estudar a relação entre caracteres inmorfofisiológicos sob regime de alagamento, determinando quais os mais importantes para estudar a tolerância dos genótipos e para avaliar a habilidade de genótipos decupuaçuzeiro em expressar fenótipos alternativos e crescer de forma eficiente, para seleçãode materiais capazes de suportar condições de hipóxia. O experimento foi conduzido em casa de vegetação,em delineamento inteiramente casualizado, em esquema fatorial 16 x 2 (16progênies e dois regimes hídricos) e quatro repetições. Os tratamentos iniciaram seismeses após o transplante das mudas. Para a avaliação experimental, foram medidos 15 caracteres relacionados ao desenvolvimento vegetativo, ao acúmulo de biomassa e às variáveisfisiológicas. Correlações entre características e componentes principais foram estimadas para estudar as inter-relações das características e identificar as mais responsivas paraauxiliar na seleção de genótipos. Os resultados revelaram que, dentre as característicasutilizadas, dez foram suficientes para explicar a variabilidade dentro da população e quatro foramescolhidas para selecionar as melhores progênies. 75% dos genótipos apresentaramtolerância ao alagamento parcial e, com base no desempenho e na plasticidade, foram selecionados G174, G48 e G56 para um espectro mais amplo, e G44, G47 e G51 apenas para condições de hipóxia.As evidências promissoras aqui levantadas precisarão ser corroboradas, com arealização de testes de campo, para que o cupuaçuzeiro possa ser recomendado narecuperaçãode ambientes sujeitos à hipóxia. SAF (SAF Theobroma grandiflorum rios, rios (rios córregos lagos etc., etc etc. , etc.) constantes eficiente hipóxia vegetaçãoem casualizado 1 16progênies progênies hídricos repetições mudas experimental vegetativo variáveisfisiológicas interrelações inter relações característicasutilizadas 75 plasticidade G174 G G4 G5 amplo G44 hipóxiaAs As corroboradas campo 7 G17 G1

Abstract Cupuassu (Theobroma grandiflorum)-based agroforestry system (AFS) can be used for restoration of vegetation around springs and riparian forests of water sources (rivers, streams, lakes etc.), subject to constant flooding. The objectives of this work were to study the relations between morphophysiological traits when flooding occurs, determining the most important to assess genotypes’ tolerance, and evaluate the ability of cupuassu genotypes to express alternative phenotypes and grow efficiently, in order to select materials capable of sustaining hypoxic conditions. The trial was carried out in a greenhouse, in a completely randomized design with a 16 x 2 (16 progenies and two water regimes) factorial scheme and four replications. Treatments started six months after the seedlings were transplanted. 15 traits related to vegetative development, biomass accumulation and physiology were measured for the experimental evaluation. Correlations and principal components were estimated to study the traits’ interrelationships and identify the most important to assist progeny selection. The results revealed that, among the evaluated traits, ten were sufficient to explain the variability within the population and four were elected as the most relevant to select the best progenies. 75% of the genotypes showed tolerance to partial flooding and based on performance and plasticity, we selected G174, G48 and G56 for a broader spectrum and G44, G47 and G51 for hypoxic conditions only. The promising evidence pointed out here will need to be corroborated with field tests, so that the cupuassu tree can be recommended in the recovery of environments subject to hypoxia. Theobroma grandiflorumbased grandiflorum AFS (AFS rivers, rivers (rivers streams etc., etc etc. , etc.) occurs efficiently greenhouse 1 (1 regimes replications transplanted development evaluation selection 75 plasticity G174 G G4 G5 G44 only tests hypoxia ( 7 G17 G1

ABSTRACT. Multi-trait multi-environment (MTME) models were fitted to eucalyptus breeding trials data to assess residual variance structure, genetic stability and adaptability. To do so, 215 eucalyptus clones were evaluated in a randomized complete block design with 30 replicates and one plant per plot in four environments. At 36 months of age, tree diameter at breast height (DBH) and pilodyn penetration (PP) were measured. Two MTME models were fitted, for which residuals were considered homoscedastic and heteroscedastic, with the best MTME model selected using Bayesian information criterion. The harmonic mean of the relative performance of the genotypic values (HMRPGV) was used to determine stability and adaptability. Of the two models, the heteroscedastic MTME model had better fit and provided greater accuracy. In addition, genotype-by-environment interaction was complex, and there was low genetic correlation between DBH and PP. Rank correlation between the clones selected by the MTME models was high for DBH but low for PP. The HMRPGV facilitated clone selection through simultaneous evaluation of stability, adaptability, and productivity. Thus, our results suggest that heteroscedastic MTME model / HMRPGV can be efficiently applied in the genetic evaluation and selection of eucalyptus clones. ABSTRACT Multitrait Multi trait multienvironment multi environment (MTME structure adaptability so 21 3 environments age (DBH PP (PP measured criterion (HMRPGV accuracy addition genotypebyenvironment genotype complex productivity Thus 2

ABSTRACT. In fruit tree breeding, selection indices are used to identify the genotypes that combine desirable commercial and non-commercial characteristics. As Theobroma grandiflorum is generally cultivated in agroforestry systems (AFS), there is a need to develop cultivars that are adapted to such environments. In this study, the objective was to select the most promising genotypes for their future use in AFS based on the additive index, a pioneering method for this crop. The trial was carried out for 12 years in an agroforestry system in the municipality of Tomé-Açu, Pará State, Brazil. The 16 evaluated clones were completely randomised with a variable number of repetitions. The average number of fruits produced as well as the morpho-agronomic characteristics of the fruits were analysed. Mixed linear models were used to estimate the components of variance and predict the genotypic values. The genetic correlation between the variables was estimated, and the selection of genotypes was based on the additive index, with a positive orientation of all variables except the thickness of the fruit shells and the weight of the fruits. Clones 42, 44, 46, 47, 57, 61, and 64 performed well for all the analysed variables, resulting in a selection gain of 7.3% and low incidence rates of witches’ broom disease. These genotypes can be made available to producers in the form of clones for use in AFS and can further be included in future hybridisations in T. grandiflorum breeding. ABSTRACT breeding noncommercial non AFS, , (AFS) environments study index crop 1 ToméAçu, ToméAçu Tomé Açu, Açu Tomé-Açu State Brazil repetitions morphoagronomic morpho agronomic values estimated 42 44 46 47 57 61 6 73 7 3 7.3 witches disease T (AFS 4 5 7.

Resumo O uso de espécies florestais na produção de mudas tem sido intensificado devido à necessidade de recuperação de áreas desmatadas e produção de biomassa. No entanto, a domesticação de espécies florestais nativas é restrita devido à falta de estudos relacionados à ecologia, fisiologia e morfologia de suas sementes. A espécie Tachigali micropetala (Ducke) Zarucchi & Pipoly, pertencente à família Fabaceae, apresenta dormência de tegumento que dificulta a entrada de água e, consequentemente, a germinação. O objetivo deste trabalho foi selecionar os melhores tratamentos para a quebra da dormência em sementes de T. micropetala. Os tratamentos foram: controle (sem tratamento pré-germinativo), desponte, escarificação em lixa, imersão em ácido sulfúrico por 5, 10, 15 e 20 minutos e imersão em água a 80 ° C por 20 minutos. A semeadura foi realizada em papel germiteste e o delineamento estatístico utilizado foi o inteiramente casualizado com oito tratamentos, cinco repetições de 25 sementes. Para o teste de sanidade, as sementes foram submetidas a dois tipos de tratamentos: assepsia com 1,5% de hipoclorito de sódio e controle (sementes sem assepsia). Cada tratamento continha 10 repetições, com 20 sementes cada. Os resultados obtidos mostram que os tratamentos em ácido por 15 e 10 minutos e a escarificação mecânica com lixa apresentaram 90,4%, 85,6% e 83,2% de germinação, respectivamente, sendo estes os mais eficientes para superar a dormência em sementes de T. micropetala. biomassa entanto ecologia Ducke (Ducke Pipoly Fabaceae consequentemente germinação T prégerminativo, prégerminativo pré germinativo , pré-germinativo) desponte 5 1 2 8 sanidade 1,5 assepsia. . assepsia) cada 904 90 4 90,4% 856 85 6 85,6 832 83 83,2 respectivamente pré-germinativo 1, 9 90,4 85, 83, 90,

Abstract The use of forest species for the production of seedlings has been intensified due to the need for recovery of deforested areas and biomass production. However, the domestication of native forest species is restricted due to a lack of studies related to the ecology, physiology, and morphology of its seeds. The species Tachigali micropetala (Ducke) Zarucchi & Pipoly, which belongs to the family Fabaceae, presents tegument dormancy that hinders the entry of water and consequently the germination. The objective of this work was to select the best treatments for breaking dormancy in T. micropetala seeds. The treatments were: control (without pre-germinative treatment), cut in the integument, scarification in sandpaper, immersion in sulfuric acid for 5, 10, 15, and 20 minutes and immersion in water at 80 °C for 20 minutes. The sowing was done in germitest paper and the statistical design used was the completely randomized with eight treatments, five replicates of 25 seeds. For the sanity test, the seeds were submitted to two types of treatments: asepsis with 1.5% of sodium hypochlorite and control (seeds without asepsis). Each treatment contained 10 replicates, with 20 seeds each. The results obtained show that the treatments in acid for 15 and 10 minutes and mechanical scarification with sandpaper presented 90.4, 85.6 and 83.2% of germination, respectively, being these the most efficient for overcoming dormancy in T. micropetala seeds. However ecology physiology Ducke (Ducke Pipoly Fabaceae germination T pregerminative pre germinative treatment, , treatment) integument 5 2 8 C test 1 1.5 asepsis. . asepsis) each 904 90 4 90.4 856 85 6 85. 832 83 83.2 respectively 1. 9 90. 83.

Resumo Uma das principais dificuldades na implantação dos sistemas agroflorestais está na escolha das espécies componentes. Esta pesquisa objetivou verificar a viabilidade de utilização de duas espécies amazônicas em sistema agroflorestal, quantificando a possível interferência da espécie dominante (mogno-brasileiro) sobre a espécie do dossel inferior (cupuaçuzeiro). O experimento foi conduzido por 14 anos, em uma propriedade comercial em Tomé-Açu, PA. Foram estabelecidos quatro níveis de espaçamento entre as árvores de cupuaçuzeiro e mogno: Nível 1 = 2,3 m; Nível 2 = 5,5 m; Nível 3 = 7,3 m; Nível 4 = 8,8 m. Avaliaram-se o desenvolvimento vegetativo inicial do cupuaçuzeiro, a produção durante 12 safras e a taxa de mortalidade. Para o mogno, mensurou-se o vigor das plantas e realizaram-se estimativas de produção de madeira. Ademais, estimaram-se alguns parâmetros morfométricos para verificar a adaptação do mogno ao ambiente de SAF e sua influência sobre o cupuaçuzeiro. Os resultados demonstraram que o cupuaçuzeiro teve um bom desenvolvimento vegetativo, mostrando não ter sido prejudicado pela competição com as árvores de mogno. A produção de frutos também não foi afetada pelo consórcio, assim como não houve diferenças nas taxas de mortalidade nos diferentes níveis de proximidade das espécies. O mogno teve crescimento vigoroso, beneficiado pelos tratos culturais dispensados, normalmente, em pomares de cupuaçuzeiro, como adubação anual e aporte hídrico. Pelas evidências obtidas, conclui-se que o SAF constituído por mogno-brasileiro e cupuaçuzeiro, nos espaçamentos aqui utilizados, oferece condições apropriadas ao desenvolvimento de ambas as espécies, e poderá ser uma alternativa aos sistemas de produção convencionais na Amazônia, bem como para incrementar a restauração de áreas antropizadas com espécies nativas.

Abstract One of the main difficulties in implementing agroforestry systems is the choice of component species. This research aimed to verify the feasibility of using two Amazonian species in an agroforestry system, quantifying the possible interference of the dominant species (Brazilian mahogany) on the lower canopy species (cupuassu tree). The experiment was conducted for 14 years, on a commercial property in Tomé-Açu, PA. Four levels of spacing between cupuassu tree and mahogany trees were established: Level 1 = 2.3 m; Level 2 = 5.5 m; Level 3 = 7.3 m; Level 4 = 8.8 m. The initial vegetative development of the cupuassu tree, the production during 12 harvests, and the mortality rate were evaluated. For mahogany, the vigor of the plants was measured and wood production estimates were made. In addition, some morphometric parameters were estimated to verify the adaptation of mahogany to the SAF environment and its influence on cupuaçuzeiro. The results showed that the cupuassu tree had a good vegetative development, showing that it was not harmed by the competition with the mahogany trees. Fruit production was also not affected by the consortium, just as there were no differences in mortality rates at different levels of species proximity. Mahogany grew vigorously, benefiting from the cultural treatments normally provided in cupuassu tree orchards, such as annual fertilization and water supply. Based on the evidence obtained, it can be concluded that the SAF made up of Brazilian mahogany and cupuassu tree, in the spaces used here, offers appropriate conditions for the development of both species, and could be an alternative to conventional production systems in the Amazon, as well as, to increase the restoration of anthropized areas with native species.

ABSTRACT Forest plantations are strong allies in preserving natural resources, providing social and economic benefits. The plantations carried out in the coming years will be vital to meet the growing demand for forest products. To ensure the continuity of genetic progress and the good results achieved with the improvement of forest species, statistical methods that accurately selects superior genotypes are desirable. Multi-trait multi-environment trials are preferred over single-trait single-environment trials, since they can exploit the covariance between traits and environments, increasing the analysis’s prediction power. The Bayesian multi-trait multi-environments approach (BMTME) combines the cited advantages with the parsimony of Bayesian statistics promoting a more informative data analysis. Thus, the aims of this study were to estimate genetic parameters, evaluate genetic variability, and select eucalyptus clones through BMTME models. To this end, a data set with 215 eucalyptus clones evaluated in four environments for diameter at breast height and Pilodyn penetration was used. The Markov Chain Monte Carlo algorithm was applied to estimate the variance components and genetic parameters and to predict the genotypic values. The Smith-Hazel index was used to simultaneously achieve gains with selection for both traits. The BMTME approach provided high accuracies, being a good strategy to the evaluation of multiple environmental trials of Eucalyptus for breeding purposes.

Abstract To meet the demands of the production chain, breeding programs need to reduce the time for selection and development of higher yielding maize genotypes. This involves application of new strategies, such as the use of the doubled haploid lines. We evaluated the use of stomatal area and density in distinguishing doubled haploids (DH) from false positive (FP) plants derived from nine tropical source populations. We selected four DH plants and two FP plants for identification of DH through leaf anatomy in the populations, in each group. Data on stomatal area and density were considered in a completely randomized model in a factorial scheme (populations and genotypes) and analyzed by restricted maximum likelihood. There were statistically significant effects of populations and genotypes for both traits. For stomatal density, the population by genotype interaction was not verified. Stomatal density proved to be efficient for distinguishing DH and FP for use in selection of doubled haploids.

Abstract Sustainable development in the Amazon involves moderate actions that combine technology-based agriculture with forest conservation. One of these actions is the genetic breeding of native species, which promotes cultural appreciation of the local society, and enables the opening of new markets. As an example, two breeding programs with solid results will be mentioned in this review: açaí palm (Euterpe oleracea Mart.) and oil palm (Elaeis guineensis Jacq. and E. oleifera (Kunth.) Cortés). Despite its importance, the prospects for breeding programs on Amazon are not optimistic. Factors intrinsic to plants, such as their incipient domestication, as well as their perennial nature and the difficulty linked to the improvement of plants in this category; and extrinsic factors, such as the lack of resources and specialized labour, in addition to the deficiency in logistics, are growing challenges that make it difficult to implementation of new programs and expansion of existing ones.

Resumo: O objetivo deste trabalho foi selecionar progênies e indivíduos de cupuaçuzeiro (Theobroma grandiflorum) com base em características agronômicas e, indiretamente, identificar aqueles adaptados a um ambiente de sistema agroflorestal (SAF) na Amazônia brasileira. Para tanto, 25 progênies de irmãos completos foram plantadas e testadas em consórcio com pimenta-do-reino (Piper nigrum), banana (Musa spp.) e bacuri (Platonia insignis). O experimento foi realizado em delineamento de blocos ao acaso, com cinco repetições e três plantas por parcela, de 2005 a 2019. Para as análises estatísticas, foram utilizadas as médias fenotípicas de produção e incidência da vassoura de bruxa avaliadas durante 11 safras. Progênies e indivíduos superiores foram identificados pela metodologia de modelos mistos (REML/BLUP), o que resultou na seleção de dez plantas de cinco famílias com características agronômicas superiores. As progênies de cupuaçu 6, 36, 37, 49 e 52 são as que melhor se adaptam ao ambiente de um SAF multiespécies na região amazônica, em razão de suas características agronômicas em condições competitivas. Dez matrizes apresentam potencial agronômico e adaptação indireta ao SAF e podem ser utilizadas como cultivares clonais de cupuaçu nesse ambiente.

Abstract: The objective of this work was to select cupuaçu (Theobroma grandiflorum) tree progenies and individuals based on their agronomic traits, and, indirectly, to identify those adapted to an agroforestry system (AFS) environment in the Brazilian Amazon. For this purpose, 25 full-sib progenies were planted and tested in consortium with black pepper (Piper nigrum), banana (Musa spp.), and bacuri (Platonia insignis) trees. The experiment was carried out in a randomized complete block design, with five replicates and three plants per plot, from 2005 to 2019. For the statistical analyses, the phenotypic averages for production and incidence of witches’ broom disease, evaluated during 11 harvests, were used. Superior progenies and individuals were identified using the mixed model methodology (REML/BLUP), which led to the selection of ten plants from five families with superior agronomic traits. Cupuaçu tree progenies 6, 36, 37, 49, and 52 are the ones that best adapt to the environment of a multispecies AFS in the Amazon region because of their agronomic traits under competitive conditions. Ten matrices show agronomic potential and indirect adaptation to the AFS and can be used as clonal cupuaçu cultivars in this environment.

RESUMO Este trabalho teve por objetivo avaliar e selecionar progênies e matrizes de irmãos completos de cupuaçuzeiro e, simultaneamente, selecionar matrizes de mogno brasileiro com características superiores, para utilização em sistemas agroflorestais (SAFs). Foram avaliadas 25 progênies de irmãos completos de cupuaçuzeiro e uma progênie de meio irmão de mogno brasileiro. O estudo foi conduzido por 14 anos em uma propriedade comercial em Tomé Açu, Pará. Para o cupuaçuzeiro, foram utilizadas como variáveis de resposta o número e a produção de frutos por planta, e a taxa de plantas com sintomas da doença vassoura-de-bruxa. Para o mogno, empregou-se a altura total, altura comercial, altura da copa, DAP e volume de madeira comercial. Os resultados revelaram cinco progênies de cupuaçuzeiro com características interessantes para emprego em SAFs. Com base nos altos valores observados na acurácia de seleção e herdabilidade, inferimos um bom potencial de seleção de indivíduos promissores na população de cupuaçuzeiro. Dez matrizes de cupuaçuzeiro foram selecionadas com base no ranqueamento dos valores genotípicos e desempenho agronômico. Para o mogno brasileiro, três matrizes apresentaram ótimo desempenho silvicultural. As matrizes destas duas espécies deverão ser propagadas vegetativamente, para avaliação em ensaios clonais.

ABSTRACT This study aimed to evaluate and select progenies and matrices of cupuassu-tree siblings, and to select Brazilian mahogany matrices with superior characteristics to be used in agroforestry systems (AFS). Twenty-five full cupuassu tree sibling progenies and one Brazilian mahogany half-sibling progeny were evaluated. The study was conducted for 14 years in a commercial property in Tomé Açu, Pará State, Brazil. The number of fruits and fruit yield per plant, as well as the rate of plants with symptoms of witches’ broom disease, were used as response variables for cupuassu. For mahogany, the following response variables were used: total height, commercial height, crown height, diameter at breast height and commercial wood volume. There were five cupuassu tree progenies with interesting characteristics to be used in AFS. Based on the high values observed in the selection accuracy and heritabilities, a good potential for the selection of promising individuals in the cupuassu tree population is inferred. Based on the ranking of genotypic values and their agronomic performance, 10 matrices of cupuassu tree were selected. For Brazilian mahogany, three matrices showed excellent silvicultural performance. The matrices of these two species should be propagated vegetatively in order to evaluate clonal tests.

RESUMO O objetivo deste trabalho foi estudar o comportamento do cupuaçuzeiro consorciado com mogno africano, a fim de definir a viabilidade do uso destas espécies em SAF e avaliar o desempenho do mogno africano em si, visando sua aplicação em programas de reflorestamento. Ambas as espécies foram avaliadas em um ensaio no município de Tomé Açu - PA, entre 2005 e 2016. Além destas duas espécies, bananeira e pimenteira do reino também faziam parte do SAF, inicialmente. Foram avaliados quatro níveis de influência do mogno sobre o cupuaçuzeiro, definidos pela proximidade entre as plantas. Foram mensurados o desenvolvimento vegetativo de ambas as espécies, bem como a produção de frutos em oito safras e a taxa de mortalidade do cupuaçuzeiro. Os resultados mostraram que a competição exercida pelo mogno africano não afetou o desenvolvimento vegetativo do cupuaçuzeiro. Na fase produtiva, até a quarta safra, a competição não era prejudicial, pois não reduzia a produção de frutos. Entretanto, a partir da quinta safra, os cupuaçuzeiros mais próximos das plantas de mogno africano apresentaram redução significativa na produção de frutos e, a partir da sexta safra, todas as plantas foram afetadas, independentemente da proximidade. Por outro lado, foi observado desenvolvimento vegetativo consistente do mogno africano, o que permite seu uso em projetos silviculturais nessa região. Concluiu-se que o mogno africano exerceu influência negativa sobre as cupuaçuzeiro. Mais estudos são necessários para avaliar se o desenvolvimento do mogno africano compensa economicamente o declínio na produção de cupuaçu.

ABSTRACT The objective of this work was to study the behavior of cupuassu trees intercropped with African mahogany in order to define the viability of using these species in AFS and to evaluate the performance of African mahogany itself, aiming its application in reforestation projects. Both species were tested in the municipality of Tomé Açu - PA, between 2005 and 2016. In addition to these two species, banana and black pepper were also part of the AFS initially. Four levels of influence of mahogany on cupuassu trees were evaluated, defined by the proximity between plants. The vegetative development of both species was measured, as well as the production of eight harvests and the mortality rate of the cupuassu trees. The results showed that the competition exerted by African mahogany did not affect the vegetative development of cupuassu trees. In the productive phase, up to the fourth harvest, the competition was not harmful as it didn’t reduce production. However, from the fifth harvest on, cupuassu trees closest to African mahogany trees showed a significant reduction in fruit production and, from the sixth harvest on, all plants were affected, regardless of proximity. On the other hand, consistent vegetative development of African mahogany was observed, which allows its use in silvicultural projects in this region. We concluded that African mahogany had a negative influence on cupuassu trees. Further studies are needed to assess whether the development of African mahogany economically compensates for the decline in cupuassu production.

Resumo O objetivo deste trabalho foi utilizar a técnica de substituição de copa para tentar reduzir o tempo de avaliação em campo e selecionar clones promissores de cupuaçuzeiro. Árvores de 15 anos de idade no campo tiveram suas copas substituídas e 16 tratamentos (clones) foram utilizados em um delineamento de blocos casualizados com 18 repetições e uma planta por parcela. O experimento durou 10 anos e foram avaliados o número médio de frutos, produção de frutos, sementes e polpa (kg/planta) e os sintomas da doença “vassoura-de-bruxa”. Os dados obtidos foram submetidos ao teste de normalidade e, posteriormente, à ANOVA. Os resultados destacaram os clones 32, 42, 44, 46, 47, 61, 62, 63 e 64, reunindo, entre eles, indivíduos com características como produtividade, tolerância à vassoura-de-bruxa e características interessantes de frutos. Os desempenhos demonstram que a técnica foi eficaz na avaliação de genótipos de cupuaçuzeiro, uma vez que os clones revelaram seu potencial, desde os primeiros anos de estabelecimento em campo. Isso permitiu reduzir em pelo menos 30% o tempo necessário para avaliar o genótipo do cupuaçuzeiro. Dos nove clones apresentados, cinco clones (32, 42, 46, 61 e 64) já devem estar disponíveis aos produtores para substituir o dossel de árvores improdutivas.

Abstract This study aimed to use the canopy replacement technique to reduce the field evaluation time and to select promising cupuassu tree clones. The study was carried out under field conditions using fifteen-year-old trees. The crowns were replaced using 16 treatments (clones). The experiment was conducted using randomized blocks design with 18 replicates and one plant per plot, during a period of ten years. The following variables were evaluated: average number of fruits, fruit, seed and pulp production (kg/plant) and symptoms of “witches broom” disease. The data were checked for normality followed by analysis of variance. The results highlighted clones 32, 42, 44, 46, 47, 61, 62, 63 and 64, presenting characteristics such as productivity, tolerance to witches’ broom disease and interesting fruit characteristics. The results demonstrate that the technique was effective in the evaluation of cupuassu tree genotypes, since the clones revealed their potential at early stages after establishment in the field. There was a reduction by at least 30% regarding the time needed to evaluate cupuassu tree genotypes. Five clones (32, 42, 46, 61 and 64) already present the potential to be made available to producers, aimed at replacing the canopy of unproductive trees.

Abstract The cultivars BRS Careca, BRS Fartura, BRS Duquesa, BRS Curinga, and BRS Golias of Theobroma grandiflorum are characterized by high levels of fruit production and diverse sources of resistance to witches’ broom disease. These cultivars are recommended for replacing the tree canopy of low yielding genotypes or forming new orchards.