Romeu de Carvalho Andrade Neto

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.

CONDICIONADORES DE SUBSTRATO PARA PRODUÇÃO ORGÂNICA DE MUDAS DE CUPUAÇU

The objective of this study was to evaluate the quality and biomass of cupuassu plants on substrates with different conditioners. The experiment was conducted in the Ecological Site Serido, Rio Branco, Acre State, Brazil. The treatments were a change of conditioner substrates, as follows: T1 = carbonized rice husk; T2 = coconut fiber; T3 = stem of palm; T4 = waste kapok and T5 = organic composte. T1, T2, T3 and T4 substrates were made by land (30%), organic compound (30%), fine coal (10%) and conditioners (30%). The substrate (T5) was considered a control with a higher proportion of land (45%) and organic compound (45%) plus addition of the fine coal (10%). All substrates were added to 1.0 kg m-3dolomitic limestone and 1.5 kg m-3 natural thermo. The experimental design was a randomized block design with five treatments and four replications of three plants each. The numbers of leaves, root, shoot and total dry matter, plant height and seedling quality index development were assessed at 120 days after sowing. The substrates containing coconut fiber, palm stalk fiber and the organic composte are viable alternatives as conditioners substrate for cupuassu seedling.

Controle pós-colheita da antracnose do maracujazeiro: amarelo com aplicação de óleo de copaíba

The objective of this study was to evaluate application of the essential oil of copaiba in controlling anthracnose in fruits of passion fruit and compare their fungicidal/fungistatic action in vitro with copaiba oleoresin. In vivo experiment, fruits were inoculated with a spore suspension of 106 conidia mL-1 and 1% Tween 80, packed in polypropylene trays and placed in a dry incubator at temperature of 25 oC and 90% of relative humidity. After 24 hours of inoculation, essential oil was sprayed at the following concentrations: T1 = 0 mL L-1, T2 = 0.25 mLL-1, T3 = 0.5 ml L-1, T4 = 0.75 mLL-1, T5 = 1.0 mLL-1, and evaluated the mass loss of the fruit, anthracnose severity and number of lesions, both at six days. For the in vitro study, we used culture media potato dextrose agar (PDA) which, after being sterilized by autoclaving (120 oC), was added copaiba oleoresin and essential oil (0, 0.5, 1.0 , 1.5 and 2.0 mL L-1). After cooling the PDA culture media was peaked to the center of the plate a mycelial disc of 12.5 mm diameter of Colletotrichum gloeosporioides and the plates incubated at 25 oC and 90% humidity. The measurement of mycelial growth was measured with the aid of analog caliper, after seven days of mycelial growth. The copaiba essential oil, in concentrations of 0.25 mL L-1 up to 1.0 mL L-1, was not effective in controlling post-harvest of the pathogen in vivo and in mass loss of passion fruits. The copaiba oils inhibited the growth of C. gloeosporioides in vitro more efficiently than the copaiba essential oil.