Antonio Aparecido Carpanezzi

Enraizamento de corticeira-da-serra em função do tipo de estaca e variações sazonais

Erythrina falcata Benth. may be used as an ornamental plant, in rehabilitation of degraded land and as a component in agroforestry systems. However seedling production from seeds is difficult. The aim of this work was to evaluate vegetative propagation of E. falcata by using stem cuttings obtained from adult trees (softwood cuttings, hardwood cuttings and regrowth cuttings) and cuttings from seedlings collected in the four seasons of the year as well as the effect of indolebutyric acid on rooting of stem cuttings. After cutting preparation, the material was treated with an indolebutyric acid solution (IBA, 0, 1.5 and 3 g L-1). Cuttings were grown in 55-mL tapered plastic containers in a greenhouse at 25 to 30oC and relative humidity above 80%. The substrate for growing of cuttings was middle texture vermiculite. The highest percentage of rooted cuttings (73%) and root length of four longest roots (46 mm) and root number (6.2) were obtained in seedling cuttings collected in the summer. No rooting was observed in cuttings collected from softwood cuttings raised from adult trees. Cutting immersion in IBA solutions had no effect on rooting. Cuttings from seedlings collected in the summer are recommended because of their high percentage of rooting and survival.

REDUCING COMPETITION IN AGROFORESTRY BY PRUNING NATIVE TREES

The degree to which pruning helps reestablish balance in agroforestry was assessed in a system established in Sao Carlos, Sao Paulo, Brazil, in 2008. Seven native tree species were planted at a density of 600 trees/ha in five strips of three rows each, and annual crops were cultivated in the 17-m crop strips between the tree strips. Competition was established after 35 months, decreasing the aboveground biomass production of corn planted close to the trees. An assessment of black oats in the dry season following tree pruning showed that the proximity of trees caused reductions in plant and panicle density, aboveground biomass production, number of grains per panicle and grain weight. Because pruning was not sufficient to maintain crop yields, tree thinning is recommended in order to minimize competition and restore conditions for adequate crop production.

Phosphorus nutrition in the growth of Bauhinia forficata L. seedlings

One of the greatest problems in the elaboration of forestation programs using native species is the lack of knowledge about seedling production. This study aimed to evaluate the growth of Bauhinia forficata seedlings submitted to phosphorus levels. Elevenday-old seedlings were transplanted to small tubettes (110 cm3) with pinus bark and vermiculite substratum base. The experiment was conducted in an entirely randomized delineation, with six P treatments: TO-control (substratum without P addition), T1-50, T2100, T3-150, T4-200 and T5-250 mg dm-3, with five replications and 20 seedlings per replication. After 60 days, the seedlings presented a 98.2% survival rate and good root formation. The height varied in function of P levels, with maximum production up to the P dose of 250 mg dm-3; 60 days after the transplant, similar behavior for leaf area and dry matter production was observed. Furthermore, the P incorporation increased the phosphorus (P), potassium (K) and nitrogen (N) accumulation in vegetable tissues. Seedling growth was positively influenced by P levels, and the maximum growth occurred up to the P dose of 250 mg dm-3. In conclusion, this characteristic showed that the species requires high levels of P during initial growth, under the tubette system.

Seed Bank from Abandoned Pastures in the Coastal Region of Paraná

The aim of the present study was to evaluate the seed bank of three contiguous areas: pasture abandoned for ten years, with soil amended by partial beheading for two years at horizon A (area I); pasture identical to the previous example, but with recent mobilization of the topsoil (area II); area in the early stages of regeneration (area III). Field work was conducted in Morretes-PR, in an area of evergreen rain forest. In November 2013, seed bank samples were collected from ten points per area (0.30 × 0.30 m) and at three depths (0-3 cm + litter, 3.1 to 6.0 cm and 6.1 to 9.0 cm). We obtained 25.151 seeds m-2, distributed between 85 species. The predominant life form was herbaceous (98%), with the Cyperaceae family being the most abundant. In the seed banks of the three areas, only a few seeds from a restricted number of woody species were found, which therefore, represents a limited resource for forest restoration purposes.

BARREIRAS AO ESTABELECIMENTO DA REGENERAÇÃO NATURAL EM ÁREAS DE PASTAGENS ABANDONADAS

There are variations in the chemical, physical and anatomy composition of wood, also among species and within species, which vary significantly with the height of the trunk and towards the bone to the shell. The objective of this study was to analyze the chemical composition of wood of Cordia trichotoma . Three tree samples were analyzed, collected in the northwest region of Rio Grande do Sul state, of which a wooden disc has been withdrawn located near the base. The ash and extractives by TAPPI were quantified and the essential oil was extracted using the method for drag steam. There were also certain chemical elements present in the wood samples, in its natural form, milled, and by spectrometry fluorescence X-ray energy dispersive -EDXRF. The wood of Cordia trichotoma showed average levels of ash and extractives of 1,39% and 28,22%, respectively. In the chemical composition of the essential oil, it was possible to identify two main oil components the α-cadinol and α-muurolol. The most abundant mineral elements were potassium, calcium, magnesium, phosphorus, sulfur and silicon. The iron was the element with lowest concentration found in the wood by the analysis technique used.

FORESTRY RESTORATION IN ABANDONED PASTURES OF Urochloa BY DIFFERENT SIZES OF BRUSHWOOD

A galharia e um metodo de complexacao ambiental, que consiste no aproveitamento de residuos vegetais. Esse metodo, quando bem estabelecido tecnicamente, pode exercer influencia sobre a qualidade da cama de sementes, favorecendo o estabelecimento de plantas nativas e a restauracao do ecossistema. Dessa forma, objetivou-se avaliar a eficiencia de galharia para a inducao da regeneracao natural de especies nativas em area coberta por gramineas exoticas inibidoras do genero Urochloa, bem como verificar o tamanho minimo necessario para conter a reinvasao das forrageiras. Como hipotese, adotou-se a largura minima de 4 m como suficiente para o estabelecimento da regeneracao natural, antes da reocupacao das forrageiras. O experimento foi conduzido entre maio 2014 e maio 2016 em Morretes-PR, na Floresta Ombrofila Densa de Terras Baixas. Foram implantados sete tamanhos de galharia: 6 x 1, 6 x 2, 6 x 3, 6 x 4, 6 x 5, 6 x 6 m e testemunha. As especies lenhosas foram identificadas e contadas e a porcentagem de cobertura herbacea estimada apos 4, 8, 12, 18 e 24 meses. Nao se verificou retomada da sucessao natural por especies nativas. Independentemente do tamanho, a galharia foi ineficiente para conter a reinvasao pelas gramineas a partir das bordas das parcelas e, como pilha de residuos, dificultou o estabelecimento de especies lenhosas. Para a criacao de safe sites e consequente restauracao via regeneracao natural, faz-se necessaria a eliminacao local das forrageiras Urochloa, sem a qual especies nativas terao pouca probabilidade de sobreviver.

ALLOMETRIC MODELS FOR ESTIMATING ABOVEGROUND BIOMASS AND BIOMASS ALLOCATION OF CAPIXINGUI TREES (Croton floribundus Spreng.) IN AN AGRISILVICULTURAL SYSTEM

O objetivo deste estudo foi selecionar equacoes alometricas para predicao da biomassa aerea total e nos compartimentos aereos de capixingui com 4,5 anos estabelecidas em um sistema silviagricola. Foram tomadas medidas dendrometricas e utilizou-se o metodo destrutivo para a estimacao da biomassa, com a separacao dos componentes em tronco, galhos e folhas. Foram ajustados e comparados quatro modelos alometricos, sendo dois de simples entrada e dois de dupla entrada. Como variaveis preditoras foram considerados o diâmetro a altura do peito (DAP), diâmetro de colo (D colo), diâmetro de copa (Dc) e altura total (H). A biomassa total estimada foi de 17,3 t.ha-1, equivalente a 86,6 kg por arvore. Todos os modelos apresentaram ajustes satisfatorios (R2aj>0,85) para tronco, galhos e biomassa total. As equacoes para biomassa total que tiveram como variavelpreditora o DAP apresentaram as melhores distribuicoes de residuos. O modelo lnW=b0+b1*lnDAP pode ser recomendado para estimativa de biomassa aerea. Para folhas, os coeficientes foram menores (R2aj>82%). A distribuicao da biomassa nos componentes seguiu a ordem: tronco>galhos>folhas. A percentagem de biomassa no tronco decresceu com o aumento do DAP das arvores enquanto que a biomassa nos galhos aumentou.

Adubação fosfatada no crescimento de mudas de Bauhinia forficata L

One of the greatest problems in the elaboration of forestation programs using native species is the lack of knowledge about seedling production. This study aimed to evaluate the growth of Bauhinia forficata seedlings submitted to phosphorus levels. Elevenday-old seedlings were transplanted to small tubettes (110 cm3) with pinus bark and vermiculite substratum base. The experiment was conducted in an entirely randomized delineation, with six P treatments: TO-control (substratum without P addition), T1-50, T2100, T3-150, T4-200 and T5-250 mg dm-3, with five replications and 20 seedlings per replication. After 60 days, the seedlings presented a 98.2% survival rate and good root formation. The height varied in function of P levels, with maximum production up to the P dose of 250 mg dm-3; 60 days after the transplant, similar behavior for leaf area and dry matter production was observed. Furthermore, the P incorporation increased the phosphorus (P), potassium (K) and nitrogen (N) accumulation in vegetable tissues. Seedling growth was positively influenced by P levels, and the maximum growth occurred up to the P dose of 250 mg dm-3. In conclusion, this characteristic showed that the species requires high levels of P during initial growth, under the tubette system.

Phosphorus nutrition in the growth of Bauhinia forficata L. seedlings - DOI: 10.4025/actasciagron.v30i5.787

One of the greatest problems in the elaboration of forestation programs using native species is the lack of knowledge about seedling production. This study aimed to evaluate the growth of Bauhinia forficata seedlings submitted to phosphorus levels. Elevenday-old seedlings were transplanted to small tubettes (110 cm3) with pinus bark and vermiculite substratum base. The experiment was conducted in an entirely randomized delineation, with six P treatments: TO-control (substratum without P addition), T1-50, T2100, T3-150, T4-200 and T5-250 mg dm-3, with five replications and 20 seedlings per replication. After 60 days, the seedlings presented a 98.2% survival rate and good root formation. The height varied in function of P levels, with maximum production up to the P dose of 250 mg dm-3; 60 days after the transplant, similar behavior for leaf area and dry matter production was observed. Furthermore, the P incorporation increased the phosphorus (P), potassium (K) and nitrogen (N) accumulation in vegetable tissues. Seedling growth was positively influenced by P levels, and the maximum growth occurred up to the P dose of 250 mg dm-3. In conclusion, this characteristic showed that the species requires high levels of P during initial growth, under the tubette system.