Eficiência de biofertilizante de rochas e matéria orgânica com adição de quitosana fungica na cultura da banana

• Autor(a) principal: SILVA, Emmanuella Vila Nova da
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4827
• topic: Biofertilizante; Matéria orgânica; Quitosana fúngica; Banana; AGRONOMIA::CIENCIA DO SOLO

In a modern agriculture the use of fertilizers and correctives aim to promote increment in food production, attending economic criterious and also to maintain the biota diversity and soil fertility, reducing environmental problems. One viable alternative is the use of phosphate and potassic rocks plus sulfur inoculated with the oxidative bacteria Acidithiobacillus. The rock biofertilizers (BPK) may produce a complete biofertilizer (BNPK) mixing with organic matter inoculated with free living diazotrophic bacteria to enrich the substrate in N by the process of biological nitrogen fixation and produce a bioprotector (PNPK) introducing the fungi Cunninghamella elegans, that contain chitin and chitosan in their cellular wall which protect plants against pathogens. In this way the aim of the study is to evaluate the effectiveness of the biofertilizer and bioprotector to observe in vitro the antifungic activity of the pathogenic fungi Fusarium oxysporum f.sp. cubense (FOC) that promote the Panana disease on banana crop; and moreover to evaluate the effects of chitosan and of the bioprotector (PNPK) to control the phitopatogen and the nutritional status of banana seedlings in cultivar resistant and sensible to the disease. Also, the objective of the study is to evaluate the effects of different fertilization treatments in some soil attributes. In the rock biofertilizer production were used two rates of elemental sulfur (10 and 20 %) inoculated with the oxidative bacteria Acidithiobacillus thiooxidans strain FG01, applying viable cells in concentration 106 mL-1. The bacterium was added in proportion equivalent to 1mL per g of elemental sulfur. In the in vitro assay the antimicrobial activity was evaluated against the FOC using the macrodilution technique with Potato - Dextrose (PD) and inoculating 0.2 mL of the spore suspention with concentration 3.5 x 106 spores mL-1, and incubated in Potato-Dextrose-Agar (BDA) without test substrate to determine the MIC (Minimum Inhibitory Concentration) and the MFC (Minimal Fungicidic Concentration), respectively. The fungi were inclubated at 28 ˚C for 7 days. The chitosan were applied in different rates (12; 10; 8; 6; 4; 2; 1 a 0 mg mL-1). The rate of chitosan equivalent to 1.0 mg mL-1 inhibits the FOC growth, and the same value was found when determined the MFC. The greenhouse experiment (pots of 2 L) used a Red Yellow Argisoil (1.5 kg vaso-1) with one seedling per pot and applying the treatments 30 days before the FOC inoculation. The banana seedlings were harvested 40 days after the pathogen inoculation and evaluated: Index of disease severity, dry shoot biomass, analyses of total N, P and K in shoots, and the soil chemical analyzes. The results showed that the biofertilizes produced in laboratory may be used to replacement of soluble fertilizers, and manufactured by low and medium producers to promote opportunities for low farmers. The results in the in vitro assays showed the antimicrobial potential of the fungi chitosan against the phytopatogenic fungi (FOC) in the banana crop and may be alternative to control the Panamá disease. The greenhouse experiment confirmed that in a general the bioprotector applied in great rates PNPK2 (150% recommended rate) and PNPK2+Q (150% recommended rate plus fungi chitosan) resulted in reduction in the index of disease severity, and independent of the cultivar, showed the best results of shoot dry biomass. The best results of the chemical analyzes turn evident the use of new fertilizer sources for reduction of the soil problems.