Jorge Ferreira Kusdra

Uso de coprólitos de minhoca na produção de mudas de mamoeiro

The purpose of this investigation was to evaluate the effect of substrates prepared with different proportion of soil and earthworm casting in the seedlings production of papaya. Two experiments were carried out in nursery of seedlings production of Federal University of the Acre - UFAC, both complying with completely randomized design with eleven treatments and ten replications. The treatments represent the mixture of different concentrations (0, 10, 20, 30, 40, 50, 60, 70, 80, 90 e 100%) of earthworm (Chibui bari) casting and soil, being dystrophic (V = 29%) in the experiment 1 and eutrophic (V = 80%) in the experiment 2. After 60 days of the planting the seeds was evaluated height of the plant and dry weight matter masses of shoot, root and total. It was verified that the addition of increasing doses of earthworm casting in the composition of the substrate resulted in increase of the growth of the plants in experiment 1 and reduction in experiment 2. The results of the experiments indicate that the use of earthworm casting in substrate prepared with soil only contributes for the increase of the growth seedlings of formosa papaya if the chemical condition of this organic material more will be appropriate than of the soil in taking care of the nutrition necessities of the plants. The results of the experiment with dystrophic soil indicate the possibility of use of the earthworm casting in the traditional production of papaya, especially in situations where the soil presents restrictions how much to the chemical condition.

Produção de mudas de alface com o uso de substrato preparado com coprólitos de minhoca

With the aim of evaluating the effect of earthworm casting (Chibui bari Righi & Guerra, 1985) in the production of lettuce seedlings (Lactuca sativa L.) cv. Simpson, two experiments ware carried out in greenhouse in the Federal University of the Acre, both in a completely randomized outline with six treatments and six repetitions, totalizing 36 experimental units, represented by 180 cm3 plastic cups. The treatments were defined from the mixture of six concentrations (0, 20, 40, 60, 80 and 100%) of soil and earthworm casting. Two soil types were used, eutrophic in the experiment 1, and dystrophic in experiment 2. At 34 days after the sowing the dry mass of shoot, root and total plant were evaluated. The results of experiment 1 indicate that the addition the earthworm casting in eutrophic soil promotes increase of dry mass of the aerial and total fast of the plant concentrations of earthworm casting 17.88% and 13.49%, respectively. However, the results of experiment 2 indicate that the addition of the earthworm casting to the dystrophic soil, responds to a cubic function, with maximum dry mass total and of root increase with concentrations of earthworm casting of 17.49% and 21.40%, respectively, with decrease in 68.23% and 67.48%, and increase maximum again with 100% of earthworm casting for both characteristics. The use of substrate prepared with soil and earthworm casting only contributes to the growth of lettuce seedlings if the chemical condition of the casting is more appropriate than the one of the soil in assisting the nutritious needs of the plants.

Caracterização química e atividade microbiana de coprólitos de Chibui bari (Oligochaeta) e do solo adjacente

Chibui bari e um oligochaeta edafico nativo da regiao amazonica, considerado como minhocucu em razao do seu grande tamanho (ate 60 cm de comprimento). Seus excrementos ou coprolitos sao liberados em monticulos com formato de torre, com altura de ate 30 cm e com materia seca de ate 2,0 kg. O objetivo desta pesquisa foi comparar a disponibilidade de nutrientes, o teor de C orgânico e a atividade microbiana dos coprolitos de Chibui bari com o solo adjacente de areas de floresta secundaria, seringal de cultivo e pastagem, localizadas na Universidade Federal do Acre - UFAC, em Rio Branco, Acre. As coletas foram realizadas considerando o delineamento em blocos casualizados, com tres tratamentos, constituidos por: a) coprolitos de Chibui bari e por amostras compostas de solos retiradas no raio de 10 cm de cada coprolito coletado, nas profundidades de b) 0-10 cm e c) 10-20 cm. Os resultados foram submetidos a analise de variância, e as medias dos tratamentos, comparadas pelo teste de Tukey a 5 %. Alem disso, efetuou-se analise de correlacao simples entre as variaveis. Os coprolitos apresentaram maiores valores de pH, P disponivel, bases trocaveis (Ca2+, Mg2+, K+), C orgânico e atividade microbiana. O teor de Al3+ foi menor nos coprolitos do que no solo na camada de 0-20 cm em 55 % (pastagem), 62 % (seringal) e 70 % (floresta). Verificaram-se, ainda, correlacoes positivas dos valores de C orgânico total (COT) com os de pH, P, K+, Ca2+ e Mg2+ e correlacoes negativas de Al3+ com COT, pH, P, K+, Ca2+ e Mg2+ nas tres areas avaliadas.

Nodulação e crescimento do feijoeiro em resposta à aplicação de molibdênio e inoculante rizobiano

The common bean (Phaseolus vulgaris) has the capacity to benefit from biological nitrogen fixation (FBN). However the success of this process is influenced by several factors. The aim of this study was to scale the magnitude of the contribution of molybdenum (sources and doses) and rhizobia (native and introduced) for nodulation, nitrogen accumulation and growth of IPR 139 bean. The experiment was conducted in 2011 in a greenhouse in a completely randomized factorial 2 x 5 x 2, corresponding respectively to the application in seeds from two sources (sodium molybdate and ammonium molybdate) and five doses of Mo (0, 1, 2, 3 and 4 g kg-1 seed) in the presence and absence of rhizobia inoculation (Rhizobium tropici SEMIA 4088). The variables analysed were: dry mass of shoot, root and total (shoot + root), dry nodules and average unit nodule, the total number of nodules and total nitrogen in aerial parts. The results indicate ammonium molybdate as the best source for raising the mass formed by indigenous rhizobia nodules, at doses between 2 and 3 g kg-1 seed. Inoculation of R. tropici SEMIA 4088 was not efficient to increase plant growth, nor nodulation and nitrogen fixation.

Atividade biológica de solo sob cultivo múltiplo de maracujá, abacaxi, milho, mandioca e plantas de cobertura

O objetivo deste trabalho foi avaliar o efeito de plantas de cobertura em cultivo consorciado de maracuja, abacaxi, mandioca e milho sobre a atividade biologica do solo em periodo chuvoso e de estiagem. O experimento foi conduzido em Rio Branco, Acre, em um ARGISSOLO AMARELO Alitico plintico. O delineamento experimental utilizado foi o de blocos casualizados completos com parcelas subdivididas e quatro repeticoes. Nas parcelas foram estudadas epocas de avaliacao (marco, maio, agosto e outubro de 2011) e, nas subparcelas, plantas de cobertura [kudzu tropical (Pueraria phaseoloides), crotalaria (Crotalaria espectabilis), amendoim forrageiro (Arachis pintoi), feijao de porco (Canavalia ensiformis) e plantas espontâneas]. Foram avaliadas respiracao (edafica e basal), biomassa microbiana, e quocientes metabolico (qCO2) e microbiano (qMIC). No final do periodo chuvoso, em condicoes de adequada umidade e oxigenacao do solo, a cobertura com crotalaria potencializa a atividade microbiana juntamente com e feijao de porco, que proporciona maior respiracao edafica. No periodo com maior restricao do oxigenio no solo (outubro a marco - estacao chuvosa) e de agua (agosto - caracteristico da estacao seca), o amendoim forrageiro mantem alta atividade microbiana. No periodo de maior precipitacao pluviometrica (marco), o solo sob plantas espontâneas apresenta maiores biomassa microbiana e eficiencia metabolica.

Crescimento do milho em solo sob atividade de Chibui bari (Oligochaeta: Glossoscolecidae)

Chibui bari (Righi & Guerra, 1985) e um minhocucu geofago, com tamanho ate 60 cm, que tem como habitat varios solos no Acre. A atividade dessa especie resulta na producao de grande quantidade de coprolitos ricos em nutrientes. O objetivo desta pesquisa foi avaliar o crescimento do milho em solo com presenca da minhoca Chibui bari. O experimento foi conduzido em casa de vegetacao da Universidade Federal do Acre, no municipio de Rio Branco, Acre, em 2009. O delineamento experimental foi inteiramente casualizado, com seis tratamentos (0, 1, 2, 3, 4 e 5 animais/tubo). O milho da variedade Bandeirante foi semeado em tubos de PVC com capacidade de 15,7 L, contendo solo de textura media. As variaveis avaliadas foram o diâmetro do colmo, as massas da materia seca da parte aerea, da raiz e total das plantas, o teor de nutrientes no solo e a atividade microbiana. A presenca de C. bari resultou em maiores diâmetro do colmo (13,29 %) e massas da materia seca da parte aerea (28,73 %) e total (33 %) do milho. Contudo, nao foi verificada mudanca significativa na condicao quimica e na atividade microbiana do solo, resultado que pode estar relacionado a maior exportacao de nutrientes do solo, exigida pelo aumento do crescimento das plantas nos tratamentos com presenca de minhocas.

Quality of Brazil nuts stored in forced aeration silos

The traditional system of collection and storage of Brazil nut compromises seriously the quality of these almonds as it contributes to the high incidence of contaminants, like fungi of the genus Aspergillus, which can produce aflatoxins. In this study, the objective was to evaluate the influence of the storage period in studied conditions, on the physicochemical characteristics and on the microbiological contamination of Brazil nuts. The experimental was designed as completely randomized, considering as treatments the storage period (0 - control, 30, 60, 90, 120 and 150 days) with four replicates of 3 kg of Brazil nuts each. The samples were submitted to physicochemical and microbiological analysis. It was observed that almonds submitted to the storage had their moisture content reduced by 78.2% at 150 days of storage, however, this reduction was not fast enough to avoid surface contamination by filamentous and potentially aflatoxins producing fungi. The critical period of contamination occurred on the first 30 days of storage when there was an increase of the studied fungi, as well as B1 and total aflatoxin. The studied storage conditions were four times more effective in reducing the product moisture content than the traditional methods, however, pre-drying is necessary to avoid contamination of the product.

Biological activity of soils under systems of organic farming, agroforestry and pasture in the Amazon

O objetivo deste trabalho foi avaliar indicadores biologicos de solos sob uso em sistemas de cultivo orgânico, agroflorestal e com pastagem no sudoeste da Amazonia. O experimento foi conduzido no Sitio Ecologico Serido, localizado em Rio Branco, Acre. O delineamento experimental foi o inteiramente casualizado com cinco tratamentos (sistemas de uso do solo) e seis repeticoes sendo que cada repeticao foi composta por quatro amostras simples. Os sistemas de uso do solo avaliados foram: 1) floresta nativa (controle); 2) sistema agroflorestal (SAF); 3) pastagem; 4) consorcio de maracuja, milho, mandioca, abacaxi e amendoim forrageiro; e 5) consorcio de maracuja, milho, mandioca, abacaxi e pueraria. Verificou-se que o sistema de cultivo orgânico consorciado com participacao de pueraria resultou em menor perda de C-CO2 por respiracao edafica e maior acumulo de carbono na biomassa microbiana. O sistema de cultivo orgânico consorciado com participacao de amendoim forrageiro resultou em maior perda do que retencao de carbono na camada de 5 a 10 cm de profundidade do solo. O solo com sistema agroflorestal foi equivalente ao controle com uso florestal no que se refere a liberacao e retencao de carbono pela atividade biologica. Na profundidade de 5 a 10 cm os solos com pastagem apresentaram biomassa microbiana similar aos em cultivo orgânico consorciado com participacao de pueraria. Porem, nesta mesma profundidade, os solos com pastagem apresentaram maior biomassa microbiana do que os com uso florestal, agroflorestal e em cultivo orgânico consorciado com participacao de amendoim forrageiro.

Qualidade industrial e maturação de frutos de laranjeiras-doce em Rio Branco, Acre.

Embora a laranjeira seja a segunda frutifera mais cultivada no Estado do Acre, atras apenas da bananeira, a producao nao atende o mercado local, dependendo da importacao de outros estados, principalmente pela falta de genotipos adaptados a regiao. Objetivou-se com este trabalho avaliar genotipos de laranjeira-doce, enxertadas sobre limoeiro Cravo, em relacao a producao e caracteristicas fisico-quimicas dos frutos em diferentes estadios de maturacao em Rio Branco, Acre. Realizou-se um experimento com delineamento inteiramente casualizado em arranjo de parcelas subdivididas no tempo considerando nas parcelas quatro genotipos de laranjeira-doce (14, 48, 51 e 55) e nas subparcelas cinco epocas de maturacao (116, 144, 172, 200 e 228 dias apos o florescimento/antese) com tres repeticoes. Nao se verificou diferenca entre as curvas de maturacao dos genotipos para massa, comprimento e diâmetro dos frutos, ratio e rendimento de suco. Houve interacao entre genotipos e tempo de avaliacao para espessura de casca, acido ascorbico, solidos soluveis, acidez titulavel e acucares totais. Na ultima avaliacao compararam-se os genotipos em relacao ao indice tecnologico, numero de sementes por fruto e produtividade, nao sendo constatadas diferencas entre os mesmos. Apesar da diferenca entre os genotipos para algumas variaveis, nao foi encontrada diferentes curvas de maturacao, nao havendo diferenca de epoca de maturacao entre os genotipos 14, 48, 51 e 55, mas sao promissores para um programa de melhoramento genetico da especie. Although the orange tree is the second most cultivated fruit in the State of Acre, behind only the banana, production does not serve the local market, depending on the importation from other states, mainly due to the lack of genotypes adapted to the region. The objective of this work was to evaluate sweet orange genotypes, grafted on Cravo lemon, in relation to the production and physicochemical characteristics of the fruits at different maturation stages in Rio Branco, Acre. An experiment was carried out with a completely randomized design in split?plot arrangement, considering four plots of sweet orange (14, 48, 51 and 55) in the split-plots and five maturation seasons (116, 144, 172, 200 and 228 days after flowering/anthesis) with three replicates. There was no difference between the maturity curves of the genotypes for fruit mass, length and diameter, juice yield and ratio. There was interaction between genotypes and time of evaluation for bark thickness, ascorbic acid, soluble solids, titratable acidity and total sugars. In the last evaluation, the genotypes were compared in relation to the technological index, number of seeds per fruit and productivity, and no differences were found between them. Despite the difference between the genotypes for some variables, different maturation curves were not found, with no maturation time difference between genotypes 14, 48, 51 and 55, but are promising for a breeding program of the species.

Quality of in-shell Brazil nuts after drying using a pilot natural convection oven in the state of Acre, Brazil

The natural drying of in-shell Brazil nuts carried out by the extractivists is not effective in reducing contamination by aflatoxin-producing fungi. Thus the use of an artificial heater could prove to be a favourable method to bring about a rapid reduction in the moisture content of the nuts and thereby prevent fungal growth. Hence the objective of this study was to evaluate the efficiency of a natural convection-type drier with respect to the physical, physicochemical and microbiological quality of nuts after drying for 6 hours at 45 °C. A random block experimental design with two treatments (nuts before and after drying) was used, using 10 replications of 3 kg. The nuts were analysed for their moisture, ash, protein, dietary fibre, total carbohydrates and lipid contents, water activity, total count of filamentous, potentially aflatoxin-producing fungi, and also the quantification of aflatoxins B1, B2, G1, G2 and the total aflatoxins. There was no effect of drying on the Aspergillus flavus and Aspergillus parasiticus counts or on the physicochemical composition of the nuts, except for the ash content. However the moisture content of the nuts was reduced by 39.7% and there was a decrease in the contamination by pre-existing total filamentous fungi. The dryer was effective in reducing the average time taken for drying as compared to the traditional method used by extractivists.