MORFOGÊNESE, CRESCIMENTO E PRODUTIVIDADE DE HÍBRIDOS DE SORGO EM RESPOSTA AO ESPAÇAMENTO ENTRE LINHAS

O plantio de híbridos de sorgo para pastejo é alternativa para a produção de forragem no Estado do Tocantins. O objetivo deste trabalho foi avaliar a morfogênese, o crescimento e a produtividade de híbridos de sorgo, para pastejo, e indentificar a densidade de plantas que promove melhor rendimento. O delineamento experimental foi em blocos completos casualizados, em arranjo fatorial 2 x 4. O primeiro fator representou dois híbridos de sorgo, sendo o BRS 800 (híbrido comercial) e CMSXS 766 (híbrido experimental), ao passo que o segundo fator contemplou quatro níveis de espaçamento entre linhas (15, 30, 45 e 60 cm) com quatro repetições, totalizando 32 unidades experimentais. As variáveis analisadas foram a altura de plantas, diâmetro do colmo, índice de área foliar, massa de folhas, massa de colmos, massa de material morto, massa de forragem, proteína bruta na folha, proteína bruta no colmo, taxa de crescimento da cultura (TCC), taxa de acúmulo de folhas (TAF), taxa de acúmulo de colmo (TAC), relação folha-colmo (FC), razão de área foliar (RAF),razão de peso foliar (RPF), área foliar específica (AFE), acúmulo de forragem verde (AFV), taxa de alongamento de folhas (TAlF), taxa de alongamento de colmos (TAlC), número de folhas vivas por perfilho (NFV), taxa de aparecimento de folhas (TApF) e filocrono em três rebrotações da planta. Ao término do estudo, observou-se que de forma geral, para todas as características avaliadas, o espaçamento de 15 cm entre linhas apresentou os maiores valores de produtividade, estimada em 13.353 kg ha-1. O sorgo para pastejo é uma opção viável para o Estado do Tocantins, sendo recomendado o híbrido CMSXS 766, em espaçamento entre linhas de 15 cm.

Sorghum hybrids for grazing is an alternative for forage production in Tocantins State. The objective of this work was to evaluate productive characteristics, growth analysis and morphogenic characteristics of sorghum hybrids for grazing and to find the density of plants that promote higher productivity. The experimental design was a randomized complete block in a 2 x 4 factorial arrangement with two sorghum hybrids (Sorghum bicolor (L.) Moench x Sorghum sudanense (Piper) Stapf) with grazing ability, BRS 800 and CMSXS 766, grown at four sowing rates (15, 30, 45 and 60 cm between lines) with four replicates, totaling 32 plots. Plant height, stem diameter, leaf area index, leaf mass, shoot mass, dead mass, forage mass, protein in leaves, protein in stems, crop growth rate, leaf accumulation rate, stem accumulation rate, leaf fullness, leaf area ratio and leaf weight ratio, specific leaf area, forage accumulation, leaf elongation rate, stem elongation rate, live leaves per tiller, leaf appearance rate and phyllochron in three regrowths. The average forage mass in BRS 800 hybrid (7.2 t ha-1) was lower than that CMSXS 766 hybrid (9.5 t ha-1). There was interaction between hybrids and sowing rate and 15 cm between lines of the hybrid CMSXS 766 showed higher crop growth rate, leaf accumulation rate, stem accumulation rate. The hybrid CMSXS 766 presented higher forage accumulation (9.2 t ha-1) and leaf elongation rate (25.2 cm-1 day-1), than BRS 800 hybrid. CMSXS 766

Decomposição e dinâmica de liberação de nitrogênio e fósforo defrações vegetais de Salvinia auriculata Aubl. em um reservatório daAmazônia legal / Decomposition and release dynamics of nitrogen and phosphorous from vegetal fractions of Salvinia auriculata Aubl. in a Legal Amazon reservoir

Este estudo teve como objetivo determinar os coeficientes de decomposição daparte submersa (PS) e aérea (PA) de Salvinia auriculata em duas profundidades da coluna de água(superfície e sedimento). Também visou avaliar o rendimento do processo de perda de massaassim como a evolução temporal dos teores de fósforo e nitrogênio. As macrófitas foramseparadas em partes; em seguida, foram secas até peso constante. Os materiais vegetais foramdepositados em sacos de decomposição e incubados no reservatório da UHE Lajeado, Tocantins.As análises dos resultados de perda de massa revelaram que não houve diferenças significativasentre os PA-sed e PA-sup (p > 0,05), entretanto, os PA-sed foram significativamente diferentesdos PS-sed (p < 0,05) e dos PS-sup (p < 0,01). Os PA-sed apresentaram k = 0,0102 dia-1 e asincubadas na superfície (PA-sup) um k = 0,0067 dia-1, os PS-sed apresentaram um k = 0,0027dia-1 e os PS-sup um k = 0,0040 dia-1. Durante os primeiros dias de decomposição foramliberadas grandes concentrações de fósforo e nitrogênio pelo processo de lixiviação; a partir do14º dia foi observada uma tendência de aumento nas concentrações de nitrogênio, fatoprovavelmente relacionado com o enriquecimento dos detritos pela biomassa microbiana.(AU)

Thisstudy aimed to determine the decomposition coefficients of the submerged (SP) and aerial part(AP) of S. auriculata at two different depths within water column (surface and sediment). It alsoquantified the decomposition yield of S. auriculata and the temporal changes of nitrogen andphosphorous content of the remaining biomass. The macrophytes were fractionated in parts andwere dried in sequence until attaining constant weight. The litterbags with plant material wereincubated in the reservoir of UHE Lajeado. The results of mass loss showed that there were nosignificant differences among the AP-sed and AP-sur (p > 0.05). However, the AP-sed wassignificantly different from SP-sed (p < 0.05) and SP-sur (p < 0.01). The AP-sed presented adecay coefficient (k) of 0.0102 day-1 and AP-sur a k of 0.0067 day-1. The SP-sed presented a k of0.0027 day-1 and the SP-sur 0.0040 day-1. It was also noticed that during the first days ofdecomposition great amounts of nitrogen and phosphorous were solubilized. This event wasrelated to the leachate process; from the 14th day of decomposition, an increasing trend wasobserved in nitrogen concentrations. This fact was probably related to detritus enrichment bymicrobial colonization.(AU)

Clinical and epidemiological characteristics of injuries caused by venomous snakes observed at the hospital for tropical diseases of Araguaína, Tocantins State, Brazil, from 1995 to 2000

Injuries caused by venomous snakes are considered a problem of public health in Brazil, and further studies for a better knowledge are very important. The aim of this work is to describe clinical and epidemiological characteristics that were observed from 1995 to 2000 in the Hospital for Tropical Diseases of Araguaína, Tocantins State, Brazil, which is a unit of health that takes care of patients suffering from tropical diseases. We studied 440 individuals and the most common characteristics observed were masculine sex, age among 15-45 years, bite in low members, and injuries caused by snakes of the Bothrops genus. The signs and symptoms more frequently observed were edema, pain, erythema, and bleeding. The most observed systemic manifestation was alteration of blood coagulation. The most frequent complications were abscess, necrosis, bacterial infection, and renal failure. The mortality rate was 3%. These data are very important for the evaluation of the problem.