Autoria: BETTIOL, W.; FRANCO, D. A. S.

Resumo: The objective of the present work was to evaluate the effect of sheep manure on the development of coffee leaf rust under greenhouse conditions. The seedlings of coffee cv. Mundo Novo were obtained from a nursery planted in washed sand and transplanted at the stage of "orelha de onça" to 5-liter plastic containers containing different substrates. The substrate was obtained by mixing a Dark Red Dystroferric Latosol with 2 kg of calcareous, 5 kg of simple superphosphate and 0.5 kg of potassium chloride per m3. Composted sheep manure was added to the mixture in the concentrations of 0; 2.5; 5; 7.5; 10; 15; 20; 30; 40; and 50% (v/v). The plants were inoculated three times, with a suspension (2 mg mL -1) of urediniospores of Hemileia vastatrix race II, in 90 days intervals. The parameters evaluated were the number of lesions per injuried leaf (NL/IL), % of infected leaves (%IL), height of the plants, total foliar nitrogen, pH, electric conductivity (EC), total microbial activity in the substrate by hydrolyses of fluorescein diacetate and lesions sporulation (LS). For the NL/IL and %IL, the response to the incorporation of sheep manure in the substrate was quadratic, reaching its maximum at 30%, for the three inoculations of urediniospores of H. vastatrix. The coefficients of determination of the quadratic curves for the NL/IL were 0.86; 0.88 and 0.94 for the first one, the second and third inoculation, respectively; while that for the %FL were 0.70; 0.26 and 0.86, respectively. The maximum increases in the NL/IL in relation to the control were 263.2; 400 and 157.3%, respectively, for the first, the second and third inoculations. Also for the height of the plants the curve of quadratic response was adjusted, with a maximum peak up at 10%. The increase in the concentration of sheep manure resulted in a significant and linear increase in the total foliar nitrogen, in pH and the EC of the substrate, with R2=O.87; 0.92 and 0.76, respectively. Sheep manure in the studied concentrations did not induce resistance to the coffee leaf rust.

Ano de publicação: 2005

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Meio Ambiente

Palavras-chave: Avaliação, Controle de doença, Esterco, Esterco de ovino, Ferrugem, Ferrugem do cafeeiro, Fertilizante orgânico, Indução de resistência sistêmica, Matéria orgânica