Almendro (Dipteryx panamensis (Pittier) Record & Mell.) is one of the native tree species with higher wood density planted in Latin American tropical region, which has given it a reputation and international acceptance in the wood-floors markets. The tree has also a remarkable ecological value, as an important food source and habitat for several endangered fauna. This research studied the potential for genetic improvement and stability of a collection of 29 open-pollinated families of Dipteryx panamensis at 48 months of age. The materials came from three different local native populations northern from Costa Rica. Individual heritabilities for commercial volume registered moderate values, between 9 % and 22 %, while mean family heritability, ranged between 47 % and 74 % for the traits evaluated. No significant genetic differences among provenances for none of the traits evaluated were observed. The genetic correlation for commercial volume between both sites showed a value of r = 0.96, which suggests low G × E interaction. If selected the top 20 individuals from the genetic ranking in commercial volume, an expected genetic gain above 50 % in year 4 can be obtained. The use of improved almendro seeds could have great impact and motivate plantations with this tree species in tropical regions. It is concluded that a unique breeding program for the whole country is feasible.

-This study aimed to evaluate IBA efficiency in mini-cuttings rooting based on four Tectona grandis clones. Vegetative samples were collected in a hydroponic mini-clonal hedge in Verde Novo reforestation company at Colider, Mato Grosso. A factorial arrangement (4 x 6) was utilized, based on Carapá, Ipê, GU5 and TB7 clones vs six IBA dosages (0, 1000, 2000, 4000, 8000 and 16000 mg L -1 ), in a randomized block design based on three repetitions and 16 mini-cuttings per experimental unit. Cutting evaluations were based on survival and rooting rates after greenhouse conditions, after shadow-house, and at sun exposure, besides, total height, collar diameter, aerial and root biomass were also analyzed. Results registered a 95,4% average survivance rate as well as a 91,8% rooting rate, considered as very high for this tree species. IBA dosages utilization did not produce a significative effect on rooting mini-cuttings from these investigated clones. However, there were different responses among clones, which suggests a genotypic effect.

Se presenta una metodología para evaluar y validar la superioridad de un árbol plus con base en su fenotipo, como parte de un programa de mejoramiento genético forestal. La metodología se basa en la evaluación fenotípica del árbol candidato y la comparación de su superioridad en relación con sus mejores vecinos en un radio inmediato de 10 a 15 m. La evaluación permite crear un registro del árbol plus y validar la superioridad fenotípica del árbol según los caracteres volumen comercial y calidad. Se revisa y discute detalle relacionado con intensidad de selección (i) y número de árboles a seleccionar en una misma finca; caracteres a utilizar; la importancia de utilizar la yema dominante y no la bifurcación en especies latifoliadas; edad de selección; entre otros aspectos. Con el fin de evitar los errores de selección tipo I: individuos seleccionados que no son superiores genéticamente y tipo II: individuos no seleccionados, pero que si son superiores genéticamente. Se revisa el método de selección por comparación con los mejores 4 vecinos en su mismo microambiente. El árbol candidato se clasifica en 2 listas según su condición de superioridad fenotípica: lista A para el árbol que presenta superioridad en volumen y calidad, y lista B para ubicar el árbol que registra superioridad fenotípica únicamente en 1 de los 2 caracteres (volumen ó calidad). La metodología permite obtener un diferencial de selección, que se puede interpretar como la ganancia potencial a obtener al seleccionar y utilizar los mejores árboles por fenotipo. Se muestra un ejemplo real basado en uno de los programas de mejoramiento genético de teca (Tectona grandis) de una de las empresas miembro de la cooperativa de mejoramiento genético GENFORES.

A teak progeny trial was established with four replicates at different sites along the northern Pacific region of Costa Rica. The trials followed a randomized block design, with 28 open pollinated families and 36 seedlings per family per site. Data from 7 years-old trees was analyzed both for each test location separately and for all locations combined. High individual heritability was found for diameter, which translates to higher breeding potential. The all locations combined analysis showed high genetic variation, with individual heritabilities reaching up to 22 %. Genotype by Environment (GxE) interactions explained only 2.5 % of total phenotypic variation. The genetic correlation (rg) among all four sites was 0.69. Hence, it is concluded that GxE interactions are not problematic for breeding purposes since they are not complex in nature. This teak breeding population showed strong genetic stability and performed well in most environments in the study area. The Hojancha location showed high genetic correlation with all other sites; therefore, it should be chosen for future testing and selection of elite genotypes. Selection of the 20 best individuals, allowing for up to two individuals per family, would result in a 1.78 cm (11 %) gain in diameter. Furthermore, based on this selection the inbreeding coefficient (F) in the offspring would only reach 2.9 %, while the expected effective population size (Ne) would be16.97 individuals. This selection scheme could reduce rotation age by almost two years, since the diameter goal of 40 cm would be reached earlier than the usual 20 years cycle. The results suggest that the progeny trial can be maintained as a single breeding population, suitable for planting in any site along the Northern Pacific region of Costa Rica.

La producción de árboles de navidad es, en Costa Rica, una actividad económica con base en el ciprés (Cupressus lusitanica Mill.) desde los años 60. Se elaboró una base de costos exhaustiva del cultivo de árboles de navidad en Costa Rica, a partir de un paquete tecnológico para un ciclo de producción de 2,5 años, que inició con la siembra de 4444 árboles.ha-1 (a 1,5 x 1,5 m) y la venta de 3111 (70%). La estructura de costos incluye como costos directos el establecimiento de 200 m de cercas.ha-1 más una estimación del costo de mano de obra que incluye la seguridad social voluntaria. El costo del jornal en el país al II semestre del 2016 se establece en ¢11.273,75 ($20,13 a una tasa de cambio de US $ 1 = C.R. ¢560). El ciclo completo de producción requiere aproximadamente 373 jornales en 3 años, unos a 125 jornales.año-1.El costo total de producción se determinó en ¢6.170.786 ($11.019,3) por hectárea, donde 60,5% corresponde a mano de obra y 39,5% a ($11.019.3), where 60.5% corresponds to labor work and 39.5%

Se evaluó un ensayo genético de Tectona grandis L. f. (Teca) conformado por 40 clones y un testigo (24 rametos por clon) distribuidos en un diseño de bloques completos al azar, con seis repeticiones y dos parejas de cada clon por bloque (parcela). El ensayo fue establecido por la empresa BARCA y la Cooperativa de Mejoramiento Genético Forestal (GENFORES) en agosto del año 2015, cerca de Jicaral, Península de Nicoya, Costa Rica. El suelo del sitio corresponde al orden vertisol, el cual es escasamente utilizado para plantaciones forestales debido a su alto porcentaje de arcillas expandibles (tipo 2:1 montmorillonítico), que forman grietas dinámicas durante el período seco. A los 8 meses de edad se realizó la primera evaluación del ensayo clonal, donde se cuantificó el diámetro a la base y altura total de cada individuo, además de evaluar la condición de bifurcación, rebrote, sobrevivencia y estado fitosanitario de cada planta. Los datos recopilados se analizaron mediante el procedimiento BLUP/REML del software SELEGEN para obtener los parámetros genéticos. Se obtuvieron resultados elevados de heredabilidad media del clon en diámetro a la base (h2mc = 83 %), altura total (h2mc = 80 %) y sobrevivencia (h2mc = 74 %). La exactitud de los parámetros registró valores superiores al 0,86 en todos los caracteres y parámetros. A los 8 meses de edad los genotipos 2, 9, 13, 21, 32 y 33 exhibieron una clara tolerancia a estos suelos vertisoles. Mientras que el genotipo 34 registró el peor desempeño y menor adaptación de la colección de clones evaluada. La sobrevivencia registrada fue de un 84 %, lo que evidencia el gran potencial de adaptación de algunos genotipos a estas condiciones de suelo. A través de la selección genética es posible identificar materiales capaces de adecuarse y producir resultados aceptables de producción en suelos sonsocuites (vertisoles).

-The study aimed to evaluate the influence of storage length on Tectona grandis mini-cuttings survival and rooting. A factorial arrangement (4 x 7) was utilized, based on four clones (Carapá, Ipê, GU5 and TB7) and seven time intervals from mini-cuttings harvesting until final sowing (0, 1, 2, 4, 8, 12 and 16 hours). A randomized block design with three replicates and 16 mini-cuttings per experimental unit was utilized. Survival and rooting rates were evaluated after greenhouse culture (30 days after sowing) and after shadow house culture (40 days after sowing); as well as height, collar diameter, aerial and root biomass 55 days after sowing. No significant differences were observed in survival and rooting rates among time intervals in teak mini-cuttings preparation from these four clones. However differences among clones were registered for rooting rate, suggesting a genotypic effect. Survival and rooting rates were very high after greenhouse culture (93% and 90% respectively), as well as survival after culture in a shadow-house (88%).Keywords: vegetative propagation, clonal forestry, teak. INFLUÊNCIA DO TEMPO DE ARMAZENAMENTO NO ENRAIZAMENTO DE MINIESTACAS DE CLONES DE Tectona grandis LINN F.RESUMO -Este estudo teve como objetivo avaliar a influência do período entre coleta/preparo e estaqueamento na sobrevivência e enraizamento de miniestacas de clones de Tectona grandis. O delineamento experimental foi em arranjo fatorial (4 x 7), considerando quatro clones (Carapá, Ipê, GU5 e TB7) que são parte do programa de melhoramento genético da empresa Agrícola VerdeNovo, selecionados em Mato Grosso, Brasil. Com sete períodos de tempo (tratamentos) entre a coleta/preparado e o estaqueamento das miniestacas (0, 1, 2, 4, 8, 12 e 16 horas), em delineamento estatístico de blocos ao ocaso, com três repetições e parcelas de 16 miniestacas. Avaliaram-se a sobrevivência e o enraizamento de miniestacas na saída da casa de vegetação (30 dias após estaqueamento) e da casa de sombra (40 dias após estaqueamento), o crescimento em altura e diâmetro do colo, a biomassa da parte aérea e do sistema radicular aos 55 dias após estaqueamento. Os resultados evidenciam que não há influência significativa do intervalo de tempo, entre coleta/preparo e estaqueamento de miniestacas de teca, na sobrevivência e no enraizamento dos quatro clones estudados. Foi constatada a existência de efeito genotípico no enraizamento dos quatro clones avaliados, os quais obtiveram altas percentagens de sobrevivência e de enraizamento na saída da casa de vegetação (93% e 90% respetivamente), assim como sobrevivência na saída da casa de sombra (88,%).Palavras-Chave: propagação vegetativa , silvicultura clonal, teca.

RESUMO:O objetivo desse trabalho foi avaliar o enraizamento de estacas provenientes das brotações advindas da decepa e do anelamento do caule de árvores de Tectona grandis, assim como de estacas originadas do sistema radicular. Foram selecionadas árvores em plantios comerciais (propagados via seminífera) de 5, 10 e 15 anos de idade, na fazenda Bacaeri, localizada no município Alta Floresta, Mato Grosso. Foram selecionadas 20 árvores por idade, sendo aplicados os três tratamentos (decepa, anelamento e coleta de raiz). O experimento seguiu um arranjo fatorial (3 x 3), em delineamento estatístico inteiramente ao ocaso, considerando as três idades e os três tratamentos testados. Com os resultados obtidos foram verificadas diferenças significativas, para a brotação e número de brotos, em relação à idade, à técnica de resgate, não obstante não foram encontradas diferenças estatísticas na interação "idade x técnica de resgate". Quanto ao enraizamento das estacas, diferenças estatísticas foram observadas somente quanto à técnica de resgate. Os resultados indicaram que as técnicas de resgate, pela decepa e pelo anelamento do caule demostraram ter potencial no resgate vegetativo desta espécie. O resgate de árvores da teca pelo método da estaquia radicular, não se torna viável nas condições avaliadas, pelo fato da baixa taxa de enraizamento (4%) e não obtenção de brotações nas estacas.Palavras-chave: propagação vegetativa, silvicultura clonal, teca, estaquia. Redemption vegetative of the Tectona grandis Linn F. trees by the stakes rootingABSTRACT: The objective of this study was to evaluate the rooting of cuttings of shoots arising from coppicing and stem girdling of teak trees, as well as stakes originated the root system. Trees were selected in commercial plantations (propagated via seminiferous) of 5, 10 and 15 years old, in Bakirifarm, located in the city Alta Floresta, Mato Grosso, Brazil. Twenty trees were selected by age, the three treatments being applied (cuts off, annealingand root collection). The experiment followed a factorial arrangement (3 x 3) in experimental design entirely to the decline, considering the three ages and the three treatments tested. With the results obtained significant differences were found for the budding and number of shoots in relation to age, rescue technique, never the less there were no statistical differences in the interaction "old x rescue technique". As for root cutting, statistical differences were observed only on the rescue technique. The results indicated that the rescue techniques by cuts off and the stem girdling demonstrated a potential in vegetative recovery of this species. The rescue of teak trees by the method of root cuttings, does not be come viable under the conditions evaluated, because of the low strike rate (4%) and not getting shoots at the stake.