%0 Journal Article
%T Efeito de bicarbonato de pot¨¢ssio sobre a severidade do o¨ªdio em plantas de soja Effect of potassium bicarbonate on the severity of powdery mildew in soybean plants
%A Regiane Medice
%A Wagner Bettiol
%A Uli Quirino de Mello Alt¨¦a
%J Summa Phytopathologica
%D 2013
%I Grupo Paulista de Fitopatologia
%X O o¨ªdio da soja, causado por Erysiphe diffusa, ¨¦ considerado uma doen a espor¨¢dica podendo ocasionar perdas quando atinge propor  es epid¨ºmicas. O trabalho teve por objetivo avaliar a efici¨ºncia de bicarbonato de pot¨¢ssio (Kaligreen ) no controle do o¨ªdio da soja. As pulveriza  es do bicarbonato de pot¨¢ssio nas concentra  es de 0; 0,25%, 0,5%, 0,75% e 1,0% e do fungicida (piraclostrobina + epoxiconazole) e as avalia  es foram semanais. Folhas foram coletadas para an¨¢lise ultraestrutural atrav¨¦s da microscopia eletr nica de varredura. O bicarbonato de pot¨¢ssio controlou a doen a em todas as concentra  es, mas causou fitotoxicidade a partir de 0,5%. Na analise ultraestrutural pode-se observar que o produto apresentou a  o direta sobre o pat¨®geno ocasionando murchamento e redu  o na germina  o dos con¨ªdios. O produto apresenta potencial para controlar a doen a, por¨¦m deve ser adequada a concentra  o a ser recomenda, bem como a frequ¨ºncia de aplica  o para evitar os problemas de fitotoxicidade. The soybean powdery mildew, caused by Erysiphe diffusa, is considered a sporadic disease which can cause losses when it reaches epidemic proportions. This study aimed to evaluate the efficiency of potassium bicarbonate (Kaligreen ) in controlling soybean powdery mildew. Sprays of both potassium bicarbonate at concentrations of 0, 0.25%, 0.5%, 0.75% and 1.0% and fungicide (pyraclostrobin + epoxiconazole), as well as assessments, were weekly carried out. Leaves were collected for ultrastructural analysis by scanning electron microscopy. Potassium bicarbonate controlled the disease at all concentrations but caused phytotoxicity from 0.5%. In the ultrastructural analysis, the product had a direct action on the pathogen, causing wilting and reduction in conidium germination. The product has the potential to control the disease, but the concentration to be recommended should be adequate, as well as the frequency of application to prevent phytotoxicity problems.
%K bicarbonato
%K produtos biocompat¨ªveis
%K doen as da soja
%K o¨ªdio
%K Erysiphe diffusa
%K bicarbonate
%K biocompatible products
%K soybean diseases
%K powdery mildew
%K Erysiphe diffusa
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-54052013000100006