No abstract

No abstract

Benzimidazoles, dicarboximides and demethylation inhibitors are the main group of fungicides used to control brown rot in Spain. The causal agents of brown rot in peach (Prunus persica (L.) Batsch) orchards in Spain are Monilinia laxa M. fructigena, and M. fructicola. The dynamics of fungicide sensitivity and fitness of M. fructicola population, the most recent species causing brown rot in the Ebro Valley (Lleida, Spain), were characterized by determining their resistance, fitness, and in vitro competitiveness to thiophanate-methyl (TM), iprodione (I), and cyproconazole (CPZ) in field isolates recovered over the 2006-2010 period. We found that: (a) more than 95 % of the M. fructicola isolates are high TM-resistant, (b) more than 50 % of the M. fructicola isolates are Iresistant and these frequencies of occurrence did not change during our 5-year survey, and (c) a few CPZresistant isolates have been also detected in population since 2008. We identified five different fungicideresistant (R) and/or fungicide-sensitive (S) phenotypes and found that our study population contains multiple fungicide-resistant isolates. Moreover, these fungicideresistant isolates display high parasitic fitness on fruit and flowers and high competitiveness. These findings suggest that the TM, I, and CPZ resistance of M. fructicola isolates could be contributing as another factor on changing the frequency of occurrence of the three Monilinia species in the Ebro Valley.

No abstract

No abstract