This study aims to identify correlations between growth variables and the Dickson quality index in seedlings of Eucalyptus grandis and Pinus elliottii var. elliottii. The experiment was conducted in a greenhouse and the following variables were observed: stem base diameter, shoot height, number of leaves, leaf dry matter, stem base dry matter, root dry matter, shoot dry matter, total dry matter, ratio of shoot dry matter to root dry matter and ratio of shoot height to stem base diameter in E. grandis 60, 75, 90, 105 and 120 days after seedling emergence, and in P. elliottii 25, 50, 75, 100, 125, 150 and 175 days after seedling emergence. Using Pearson correlation and also path and regression analyses, correlations were analyzed between observed variables according to day after emergence and the Dickson quality index. Stem base diameter was found to have stronger correlation with days after emergence in comparison to shoot height, in both species. Root dry matter was found to have stronger correlation with the Dickson quality index. Stem base diameter was the most suitable parameter to indicate seedling quality due to its higher correlation level with the Dickson quality index. Shoot height was only effective to indicate seedling quality if analyzed together with stem base diameter. Variables relating to dry matter showed the highest correlations with the Dickson quality index (DQI), followed by stem base diameter. Conversely, number of leaves showed the poorest correlations with DQI, followed by seedling height.

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Correlations between growth variables and the Dickson quality index in forest seedlings

The Enterolobium contortisiliquum (Vell.) Morong. is a tree of Brazilian origin, occurring from north to south, from the family Leguminosea-Mimosoideae. The objective of this study was to evaluate the effect of different substrates on germination and seedling growth of tamboril. The treatments were: T1 - soil, T2 - soil + manure, T3 - soil + carbonized rice straw and T 4 - soil + manure + carbonized rice straw. The evaluated variables included emergence percentage, emergence speed index, plant height, number of leaves, stem diameter, weight of the fresh and dry matter on the aerial parts and weight of fresh and dry root. The experimental design was completely randomized with four treatments and five replications of 20 seeds. The emergence and the emergence speed index had better performance in substrates soil +manure and soil + carbonized rice straw. The characteristics of the seedlings growh at 120 days after sowing has positively influenced by the presence of manure in the composition of the substrate.

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Germinação e produção de mudas de tamboril (Enterolobium Contortisiliquum (Vell.) Morong) em diferentes substratos

Caesalpinia ferrea is a species used a lot as a medicinal plant, for urban arborization and landscape design in the state of Amapa. Yet there is not much ecophysiological information available on it. Light is an important environment factor that controls processes associates with the accumulation of dry matter, contributing thus for plant growth. The object of this research was to study the effect of different luminosity levels on the growth of seedlings of this species. The seedlings were transplanted to plastics bags containing a mixture of soil and sand (2:1), which were maintained in the full sun, under artificial shade with reduction of 50% and 70% of the luminosity and under natural shade of a closed canopy of forest. The experimental design was completely randomized with five replicates. Seedlings submitted to natural shade showed strong growth inhibition. In the full sun, the seedlings presented higher net assimilatory rate (NAR), lower shoot/root ratio (SRR) and lower leaf area ratio (LAR). The results showed little difference in the growth and biomass allocation between seedlings kept in 50 and 70% shade; the seedlings submitted to this treatment presented higher values of SRR and LAR. This indicates plasticity which influences a possible increase in light capture and is important, therefore, to keep the seedling growth and survival under low light levels. The results as a whole showed morphological and physiological adjustment to different light levels in Caesalpinia ferrea.

/pdf/efeitos-da-luminosidade-no-crescimento-de-mudas-de-20qta2urvc.pdf

Efeitos da luminosidade no crescimento de mudas de Caesalpinia ferrea Mart. ex Tul. (Leguminosae, Caesalpinoideae)

Considerando a crescente demanda por mudas florestais e a escassez de materias-primas dos substratos utilizados para o crescimento das plantas, faz-se necessario avaliar novos componentes e formulacoes que assegurem a qualidade das mudas. Nesse experimento foram estudados o desenvolvimento e a qualidade de mudas clonais de Eucalyptus urophylla x E. grandis, provenientes de miniestacas, em funcao de nove composicoes de substrato produzidos a partir de vermiculita granulometria fina, casca de arroz carbonizada e fibra de coco em tubetes de 50 mL. Foram avaliados as propriedades fisicas dos substratos, o desenvolvimento morfologico e a qualidade do sistema radicular das mudas, aos 90 dias apos o estaqueamento. Os substratos com maior porosidade total promovem maior qualidade do sistema radicular o que, consequentemente, resulta em mudas com maior diâmetro, massa seca aerea e radicular e Indice de Qualidade de Dickson. Outros valores para as caracteristicas fisicas dos substratos, diferentes dos citados na literatura, tambem podem ser considerados adequados.

/pdf/qualidade-de-mudas-clonais-de-eucalyptus-urophylla-x-e-44z1m0ihih.pdf

Qualidade de mudas clonais de Eucalyptus urophylla x E. grandis em função do substrato

RESUMO – O presente trabalho foi desenvolvido com o objetivo de verificar a influencia da saturacao por bases do substrato sobre o crescimento e a qualidade de mudas de Anadenanthera macrocarpa (angico-vermelho). O delineamento experimental utilizado foi inteiramente casualizado, com quatro repeticoes por tratamento. Foram empregados tres solos como substrato, e para cada um deles a saturacao por bases original foi elevada aos seguintes valores: Latossolo Distrofico, 30,0; 50,0; e 70,0%; Latossolo Alico, 25,0; 45,0; e 65,0%; e Argissolo, 50,0; 60,0; e 70,0%. Foram avaliados os parâmetros morfologicos das mudas, suas relacoes e o indice de qualidade de Dickson. A saturacao por bases nao teve influencia em nenhum dos parâmetros avaliados quando o substrato utilizado foi o argissolo. Exceto no diâmetro do coleto, a elevacao da saturacao por bases exerceu influencia significativa, com padrao linear sobre os parâmetros morfologicos, suas relacoes e no indice de qualidade de Dickson para mudas produzidas no Latossolo Distrofico. No Latossolo Alico foi observado influencia significativa com um comportamento quadratico sobre as caracteristicas avaliadas, sendo os melhores crescimentos e qualidade encontrados quando a saturacao por bases estava proxima de 50,0%.

/pdf/crescimento-e-qualidade-de-mudas-de-anadenanthera-macrocarpa-2ykd6ban79.pdf

Crescimento e qualidade de mudas de Anadenanthera macrocarpa (Benth.) brenan em resposta à saturação por bases do substrato

This work aimed to verify the influence of the under shading period in the parameters employed to evaluate Trema micrantha (crindiuva) seedling quality pattern. The research was carried out using a randomized design, with four replications per treatment and 88 plants per replication. Three evaluations were performed at 90, 120 and 150 days after emergence. The following treatments were used in the evaluation: Evaluation I, 45, 60, 75 and 90; Evaluation II, 45, 60, 75, 90, 105 and 120 and Evaluation III, 45, 60, 75, 90, 105, 120, 135 and 150 days under shading with 48% of solar radiation retention, respectively. The morphological parameters of the seedlings, their relationships, and the Dickson quality index were evaluated. Seedlings developed under the longer shading periods presented higher shoot heights and leaf area but the lowest values for seedling quality, such as smaller stem diameter, root dry mass and the Dickson quality index. They also presented an increase in shoot height/stem diameter and shoot/root ratios. Period under shading did not affect significantly the parameters for leaf area, leaf dry mass, shoot and total. Seedlings showed better quality patterns at 120 days, when grown under 45 and 60 days under shading. The Dickson's quality index was the best and the most suitable parameter to evaluate the target seedling grown in a suspended nursery.

https://www.scielo.br/pdf/rarv/v26n4/a15v26n4.pdf

Padrão de qualidade de mudas de Trema micrantha (L.) Blume, produzidas sob diferentes períodos de sombreamento

Aiming to evaluate the effect of pre-puberty castration on traction horses' body development, the experiment was carried out with 18 cross breeding Mangalarga foals. The animals belonged to the same stallion offspring and were castrated at 2 months old. The following characteristics were measured at ages 2, 12 and 24 months: the hights of withers, back chine, hook, ribs and chest floor, the lengths of body and rump, the widths of thurl, hook and chest and the perimeters of limbs and thorax. Besides, loading, capacity, body, morphological, chest and dactyl-thorax indexes were also measured. The results showed that there were not significant differences between castrated and non-castrated animals for almost all measured characteristics. However, castrated horses had greater liveweight, thorax perimeter and index capacity than non-castrated animals. Thus, it was concluded that pre-puberty castration is feasible.

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Efeito da castracao pre-pubere sobre o desenvolvimento corporal de equinos

The effect of oestradiol benzoate (OB) on mortality rate and performance of a sample of 706 newborn Large White x Landrace piglets from 62 litters. After being individually weighed, they were divided into 3 treatments: T0, T1 and T2. T0 piglets weighing less than 1.200g were administered commercial drug (0.1mg OB, 0.1ml ethanol, 2.5mg chlorobuthanol diluted 0.9ml vegetal oil). T1 piglets weighing less than 1.200g also received similar commercial drug, with the exclusion of OB. T2 group weighing over, 1.200g received no treatment. Each litter was considered a replicate. Mortality rates for T0 and T1 were respectively 25.82% and 25.45%, while 5.62% for T2 showed to be significantly different (P≤0.05). Mortality rate was not influenced by OB administration, but only by the weight at birth. The weight gain from birth to 21-day age was different (P≤0.05) between T0 (4,199.6g), T1 (4,045.1g) and T2 (3,958.9g), but showed no significant difference between the treatments for weight at 21-day age.

Nilva Aparecida Nicolao Fonseca

Papers

Padrão de qualidade de mudas de Trema micrantha (L.) Blume, produzidas sob diferentes períodos de sombreamento

Efeito da castracao pre-pubere sobre o desenvolvimento corporal de equinos

Efeito do benzoato de estradiol sobre a taxa de mortalidade e sobre o desenvolvimento de leitões nascidos com peso inferior a 1.200g