Effect of diazotrophic bacterium inoculation and organic fertilization on yield of Champaka pineapple intercropped with irrigated sapota.

The purpose of this study was to evaluate the response of the Champaka pineapple to inoculation with the diazotrophic bacterium Asaia bogorensis (strain 219) when grown with organic fertilizer in an irrigated sapota orchard. Plantlets were transplanted to tubes containing a mixture of worm compost and vermiculite and inoculated with 108 bacterial cells. After five and a half months of acclimatization the plantlets were transplanted in furrows in the sapota orchard. Fertilizer was placed at the bottom of the furrows and covered with three doses (2.5; 5.0 and 7.5 L linear m−1 row) of three organic composts. The successful association of the plantlets with the diazo-trophic bacterium was confirmed by most probable number analysis before transferring to the field. Plants inoculated with strain AB219 showed the greatest initial leaf growth and produced the heaviest fruits compared to uninoculated plants. Plant growth and fruit yield increased with increasing compost dosages. The results suggested that Champaka pineapple benefited from the association of A. bogorensis (strain 219) when grown under irrigation and with organic fertilizer.

Influence of Pseudomonas putida AF7 inoculation on soil enzymes.

There has been some concern about the environmental impact of microbial agents. Pseudomonas may be used as bioremediator and as biopesticide. In this study, we report the use of soil enzyme assays as biological indicator of possible negative effects in soil functioning after the P. putida AF7 inoculation. For that, P. putida AF7 was originally isolated from the rizosphere of rice and was inoculated on three soil types: Rhodic Hapludox (RH), Typic Hapludox (TH); and Arenic Hapludult (AH). The acid phosphatase, b-glucosidase and protease enzymes activities were measured for three period of evaluation (7, 14 and 21 days). In general, the enzymatic activities pre- sented variation among the tested soils. The highest activities of b-glucosidase and acid phosphatase were observed in the RH and AH soils, while the protease activity was higher in the TH soil. Also, the soil charac- teristics were measured for each plot. The activity of enzymes from the carbon cycle was positively correlated with the N and the P and the enzyme from the nitrogen cycle was negatively correlated with N and C.org. The presented data indicate that soil biochemical properties can be an useful tool for use as an indicator of soil perturba- tions by microbial inoculation in a risk assessment.

Influence of Pseudomonas putida AF7 inoculation on soil enzymes.

Pseudomonas may use as bioremediator and as biopesticide. The use of soil enzymatic assays as biological indicator of possible negative effects in soil functioning was evaluated after P.putida AF7 inoculation. For that, AF7 was originally isolated from the rizosphere of rice and was inoculated on three soils: Rhodic Hapludox (RH), Typic Hapludox (TH); and Arenic Hapludult (AH). Soil characteristics were measured in each plot. Acid phosphatase, ?-glucosidase and protease activities were measured at 7, 14 and 21 days. The enzyme activity waved during the experimental period but there is a significant reduction of ?-glucosidase activity in RH soil on day 14. Corg was positively correlated to the activities of ?-glucosidase and protease. The presented data indicate that soil biochemical properties may be useful as indicator of soil perturbations.

Influence of pseudomonas putida af7 inoculation on soil enzymes activities.

2008

Influence of Pseudomonas putida AF7 inoculation on soil enzymes activities.

2008

A method for Colletotrichum graminicola inoculation in maize stalks.

A podridão do colmo do milho causada por Colletotrichum graminicola causa perdas severas em lavouras de milho. Estudos com resistência de plantas e variabilidade genética do patógeno são necessários para o desenvol-vimento de estratégias de manejo desta doença. Por outro lado, há ausência de uma metodologia adequada para a inoculação de C. graminicola em colmos. O objetivo principal do trabalho foi estabelecer uma metodologia confiável e prática para a inoculação de C. graminicola. Foram avaliados três métodos de inoculação em colmo: palitos de dente colonizados por micélio; palitos de dente imersos em suspensão de conídios; e injeção de suspensão de conídios. Nós também determinamos o efeito da posição do entrenó inoculado, o estádio fenológico para a inoculação e o período de tempo ideal após a inoculação para avaliar a severidade da doença. O método de palitos de dente imersos em suspensão de conídios inoculado no terceiro entrenó no estádio fenológico de pendoamento (VT) e avaliado aos 30 dias após a inoculação obteve o melhor resultado. A metodologia foi validada em plantas cultivadas em condições de campo.