Identification and modeling of the risk of chemical and physical factors to the incidence of fusarium wilt of passionflower in Bahia

A fusariose do maracuja e uma doenca causada por um fungo de solo, Fusarium oxysporum f. sp. passiflorae (FOP), seu sintoma tipico e a murcha. A Bahia e o principal produtor da fruta, porem a producao esta sendo comprometida devido a esse problema fitossanitario. Os nutrientes podem aumentar ou diminuir a resistencia das plantas a patogenos. Sendo assim, o objetivo desse trabalho foi identificar e quantificar a relacao de risco entre fatores abioticos do solo e a incidencia de fusariose do maracuja em plantios no estado da Bahia. Ao todo foram coletadas 50 amostras de solo, na profundidade de 0-20 cm. As analises quimicas determinaram os valores de pH, macro e micronutrientes, e a classificacao textural atraves de analise granulometrica. Constatou-se predominância de solos alcalinos. Em relacao a classe textural, a franco arenoso foi verificada em 60% das amostras. Os dados de incidencia em plantas se correlacionaram positivamente com pH, V e areia muito fina, ja os valores de H+ Al, Fe e silte se correlacionaram negativamente. Para incidencia em covas, pH, V, Mn/Fe e areia muito fina apresentaram correlacao positiva, e H+ Al, Fe e silte se correlacionaram de forma negativa. De maneira geral, os elementos que se correlacionaram positivamente e negativamente com as incidencias, podem indicar conducividade e supressividade a doenca, respectivamente. Alta incidencia da doenca foi associada a teores de areia muito fina acimas de 104 g/kg de solo. As variaveis, irrigacao e classificacao textural nao apresentaram diferenca significativa (p Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri",sans-serif;} A B S T R A C T The passion fruit scab is a disease caused by a soil fungus Fusarium oxysporum f. sp. passiflorae (FOP), its typical symptom is wilting. Bahia is the largest producer of the fruit, but the production is being compromised because of this pest problem. Nutrients can increase or decrease the resistance of plants to pathogens. Thus, the aim of this study was to identify and quantify the risk relationship between abiotic factors of soil and the incidence of fusarium passion fruit plantations in the state of Bahia. Altogether they were collected 50 soil samples at a depth of 0-20 cm. Chemical analysis determined the pH, macro and micronutrients, and texture classification using the sieve analysis. There is a predominance of alkaline soils. Regarding the texture class, the sandy loam was observed in 60% of samples. The incidence data on plants were positively correlated with pH, V and very fine sand, since the H + Al values, Fe and silt were negatively correlated. For incidence in pits, pH, V, Mn / Fe and fine sand were positively correlated, and H + Al, Fe and silt correlated negatively. In general, the elements that positively and negatively correlated with the incidence may indicate conduciveness and supressiveness the disease, respectively. High incidence of the disease was associated with very fine sand content acimas 104 g / kg soil. The variables, irrigation and textural classification showed no significant difference (p Keywords: fusarium wilt, passionflower, pH, sand