Sigatoka-amarela da bananeira em função da nutrição mineral em solução nutritiva e da distribuição espacial da fertilidade do solo

Abstract

This work was performed aiming at evaluating yellow Sigatoka in banana seedlings grown in nutrient solution and on nutrient omission, as well as to determining the spatial pattern of disease in the field, correlating it with balanced nutrition using geostatistical analyst. In nutrient solution, the nutrients omission caused visual deficiency symptoms in seedlings and reached the highest areas under the number of lesions of yellow Sigatoka curve progress for treatments without K and S. However, it was not possible to assess yellow Sigatoka severity until 60 days after inoculation due the extreme deficiency symptoms in inoculated leaves. Using geostatistics in the field work we found that the main grid showed a moderate degree of spatial dependence with a range of 193.71 m and the subgrid showed a strong degree of spatial dependence with a range of 6.58 m. Besides, we adjusted the exponential model for both grids and through ordinary kriging maps, it was possible to found a positive relationship between yellow Sigatoka severity with levels of phosphorus, nitrogen, potassium, and calcium and negative relationship with levels of magnesium, copper and manganese