Abstract The objective of the study was to determine whether Parkia platycephala families with superior morphophysiological traits perform consistently across four stages of early development (plantlets, seedlings, and juveniles at 34 and 60 months), as a means to assess the possibility of conducting pre-selection. For 21 morphophysiological traits, the following genetic parameters were estimated: heritability, coefficients of variation (genetic, relative, and environmental), accuracy, genetic and phenotypic correlation, percentage of coincidence (PC) of the best families, effective population size, and inbreeding in three progeny tests conducted under laboratory, nursery, and field conditions. Families of P. platycephala showed significant phenotypic and genotypic differences. The traits evaluated show genetic control. The percentage of coincidence between the best families was more accurate when the selection intensity was greater than 50% (PC ≥ 52%). Based on the evaluated traits, a pre-selection strategy at the juvenile stage for P. platycephala was researched to effectively identify superior families.

ABSTRACT Background: The conservation and restoration of forest landscapes is an important aspect of sustainable development. In semi-arid regions these practices are difficulted by the harsh climate of these environments, with low precipitation values and prolonged dry seasons. The objective of this study is to identify tree species from the south of the Brazilian state of Piauí that have potential to be used in forest restoration programs. Results: Data from forest inventory and tree characteristics were used to select eight tree species using target species definition, focusing on species with desirable wood properties, abundance in the study region, favorable dendrometric variables, seed availability, ease of seed germination and seedling growth in nursery and field conditions, among others. These species were then evaluated as candidates for restoration using a framework species approach focusing on the following attributes: (i) 70% or higher seedling survival in the field; (ii) seedling height of 45 cm or taller after the first growing season in the field and (iii) 70% or greater nursery seedling survival. Conclusion: The species Combretum glaucocarpum, Cenostigma macrophyllum, and Pityrocarpa moniliformis are suitable to be employed in forest restoration programs in the southern region of Piauí, Brazil. Further studies must be carried out to assess the behavior of these and other potential tree species in long term field conditions and under varying silvicultural regimes, a key aspect for forest restoration.

ABSTRACT Water is considered the most important environmental resource for the germination process. This study aimed to evaluate the germination performance of Parkia platycephala seeds under different conditions of water and saline stress. Seed germination was tested with solutions of poly (ethylene glycol) 6000 and sodium chloride (NaCl) at seven osmotic potentials [0.0, -0.2, -0.4, -0.6, -0.8, -1.0, and -1.2MPa (megapascal)] and four replicates with 25 seeds in a completely randomized design, simulating the water and saline stress levels, respectively. The following seedling variables were evaluated: germination percentage, germination speed index, length, and dry mass. Results showed significant interaction between the agent and the osmotic potential for all evaluated variables. P. platycephala seeds presented higher tolerance to saline stress simulated by NaCl than to water stress, showing germination performance appropriate for glycophyte plants.

RESUMO Alternativas sustentáveis devem ser adotadas para minimizar os impactos ambientais negativos das atividades agrícolas. A utilização de águas residuárias assim como de resíduos orgânicos oriundos das atividades agrícolas ou encontrados naturalmente como o caule decomposto do buritizeiro, podem constituir uma alternativa sustentável para a produção de mudas para fins de reflorestamento de áreas em processos de degradação e desertificação, comuns no Piauí, Brasil. Objetivou-se neste trabalho, avaliar o crescimento e qualidade de mudas de Acacia mangium Willd cultivadas em substratos com diferentes proporções de caule decomposto de Mauritia flexuosa (CDB) e irrigado com água residuária da suinocultura (ARS). O delineamento experimental foi inteiramente casualizado, disposto em esquema fatorial 5 x 2, referentes a cinco proporções de CDB e solo (v/v, %: 0:100; 20:80; 40:60; 60:40; 80:20) e duas origens de água de irrigação (água de poço e ARS), com quatro repetições. Aos 100 dias após semeadura (DAS), as mudas foram coletadas para mensuração das variáveis relacionadas ao crescimento, qualidade e nodulação. A altura, o diâmetro do coleto, a massa seca da parte aérea, a área foliar e o acúmulo de nitrogênio na parte aérea, foram influenciados significativamente (p≤0,05) pela interação entre os substratos e a origem da água de irrigação. A ARS não influenciou significativamente o crescimento e qualidade das mudas de Acacia mangium Willd. A melhor relação entre o substrato CDB:solo foi a proporção 46:54, considerada a mais adequada à produção de mudas de Acacia mangium Willd.

ABSTRACT Sustainable alternatives should be adopted to minimise the negative environmental impacts of agricultural activities. The use of wastewater as well as organic waste, from agricultural activities or found naturally, such as the decomposed stems of the Buriti palm (Mauritia flexuosa), can be a sustainable alternative in the production of seedlings for the reforestation of areas in the process of degradation or desertification, common in the State of Piauí, Brazil. The aim of this study was to evaluate growth and quality in seedlings of Acacia mangium Willd grown in substrates with different proportions of decomposed stems of Mauritia flexuosa (DSB), and irrigated with wastewater from pig farming (WPF). The experimental design was completely randomised, arranged in a 5 x 2 factorial scheme, corresponding to five proportions of DSB and soil (v/v,% - 0:100, 20:80, 40:60, 60:40, 80:20), and two sources of irrigation water (well water and WPF), with four replications. At 100 days after sowing (DAS), the seedlings were collected to measure the variables related to growth, quality and nodulation. Height, root collar diameter, shoot dry weight, leaf area and nitrogen accumulation in the shoots were significantly influenced (p≤0.05) by the interaction between substrate and source of irrigation water. The WPF had no significant influence on the growth or quality of the Acacia mangium Willd seedlings. The best ratio between DSB substrate and soil was 46:54, considered the most suitable for seedling production in Acacia mangium Willd.

RESUMO: Objetivou-se no presente estudo avaliar o comportamento e o crescimento de clones de seringueira ( Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.) introduzidos na região noroeste do estado de Minas Gerais. O delineamento utilizado foi o de blocos casualizados, constituído por 12 clones de seringueira, quatro repetições, avaliadas em esquema de parcelas subdivididas no tempo: aos 62, 77, 87, 99, 113 e 128 meses após o plantio. Foram avaliadas a sobrevivência, a circunferência e altura total da planta. A partir dessas informações, foram calculados o incremento corrente anual e o incremento médio anual da variável circunferência, e o número de árvores aptas à sangria. Os resultados obtidos indicaram que os clones GT 1, IAN 2880, IAC 15, RRIM 600, PB 235 e IAN 3156 apresentam potencial de estabelecimento às condições edafoclimáticas da região. O crescimento em altura e circunferência ao longo do período de avaliação evidencia que os clones de seringueira apresentam diferentes ritmos de crescimento na região de estudo. Os clones GT 1, IAN 3087, IAN 3156 e PR 255 foram os que apresentaram maior circunferência de caule aos 128 meses, sendo o clone PR 255 o único clone apto à sangria aos 128 meses de idade após o plantio.

ABSTRACT: This study aimed to evaluate the growth of rubber tree clones ( Hevea brasiliensis (Willd.exA.Juss.) Müll. Arg.) in the Northwest region of Minas Gerais, Brazil. Randomized blocks, constituted of three treatments (rubber tree clones) and four repetitions were used, and evaluated as plots subdivided in time. Subplots represent the evaluations carried out at the ages 62, 77, 87, 99, 113 and 128 months after planting. It was evaluated survival, stem circumference and total plant height. Current annual increment and average annual increment of circumference and also the number of trees fit for rubber tapping were calculated. Results obtained indicate that clones GT 1, IAN 2880, IAC 15, RRIM 600, PB 235 and IAN 3156 have potential to establish under local edaphoclimatic conditions. Increase in plant height and stem circumference throughout the evaluation period makes it evident that the clones have different growing paces in the studied region. Clones GT 1, IAN 3087, IAN 3156 and PR 255 had larger stalk circumference at 128 months, and PR 255 was the only one fit for rubber tapping at the age of 128 months after planting.

ABSTRACT The objective of this study was to carry through the economic analysis of two production systems of Eucalyptus grandis / Eucalyptus urophylla hybrid seedling. The data was collected in a forest nursery, which belonged to a Forest Company, located in the State of Minas Gerais. Production costs were quantified for the seedling obtained through the mini-cutting technique (SM), as well as for those produced through the system using seeds (SS). The two systems presented economically viable results; however, profitability varied between them, favoring the (SS) system. The economic analysis is important for the planning and implantation of this activity.

RESUMO O objetivo deste estudo foi realizar a análise econômica de dois sistemas de produção de mudas do híbrido de Eucalyptus grandis com Eucalyptus urophylla. Os dados foram obtidos em um viveiro localizado no Estado de Minas Gerais e pertencente a uma Empresa Florestal. Foram quantificados os custos de produção de mudas produzidas através do sistema de miniestaquia (SM) e do sistema utilizando sementes (SS). Os dois sistemas apresentam resultados economicamente viáveis, porém, a lucratividade variou entre eles, sendo maior no SS. A análise econômica é importante para o planejamento e implantação da atividade.

O experimento foi conduzido com o objetivo de obter informações sobre a influência do estádio de desenvolvimento do fruto (época de coleta) e do tipo de congelamento sobre os componentes nutricionais e de textura da polpa de pequi (Caryocar brasiliense Camb.). Os frutos foram coletados na árvore, antes da queda natural; no chão, após a queda natural, e após a queda natural, mantidos três dias em condição ambiente. Em cada época de coleta, após a retirada da casca dos frutos, um grupo de putamens foi congelado diretamente em freezer, e outro, congelado em nitrogênio líquido, antes do congelamento em freezer. Após seis meses, foi retirada a polpa dos putamens para a análise dos teores de carotenóides totais, ß -caroteno, licopeno, vitamina A, proteínas e lipídios; teor de celulose, hemicelulose, pectinas total, cálcio ligado à parede celular e total, atividade da pectinametilesterase e poligalacturonase. Os resultados indicaram que os teores de pigmentos, lipídios, proteínas e atividade da PG aumentaram com o avanço do estádio de maturação dos frutos. Por outro lado, houve diminuição no teor da celulose com avanço do estádio de maturação, enquanto os teores de hemicelulose e cálcio não foram influenciados pela idade do fruto. O tipo de congelamento interferiu nos teores de pigmentos, maiores na polpa congelada em nitrogênio líquido, e na atividade da PG, maior na polpa congelada apenas em freezer. Por último, os resultados mostraram que os frutos coletados na árvore são nutricionalmente inferiores aos coletados após a queda natural.

The experiment was carried out with the purpose to obtain information about changes in the constituents responsible for nutritive and texture traits of pequi pulp related with harvest time and types of freezing. Fruits were collected in the tree before natural fall, in the ground after natural fall and in the ground three days after natural fall. In each harvest time, while one batch of the putamens was frozen in liquid nitrogen and afterwards stored in a freezer, another batch was frozen directly in the freezer. After six months the following analyses were performed in the pulp: contents of proteins, total carotenoid, b-carotene, licopene, vitamin A and lipids (nutritive characters); content of cellulose, hemicelluloses, total pectin, total and bound calcium, activity of polygalacturonase (PG) and pectinmethilesterase (PME) of the cell wall. The contents of pigments, lipids, proteins and activity of PG were the highest in the most advanced stages of maturation of fruits. On the other hand the content of cellulose decreased with the advanced stages of maturation whiles the content of hemicelluloses, total and bound calcium were not affected at the stages of maturation of the fruits. The types of freezing affected the contents of pigments; higher in the pulp frozen in liquid nitrogen; and the activity of PG was higher in the pulp frozen directly in the freezer. The fruits collected in the tree showed the lowest eating quality as judged by their lowest contents of pigments, protein and lipids. The results indicate that the most appropriate harvest time to higher quality of pequi fruits is after natural fall.