Imazalil concentration for in vitro monitoring of imazalil resistant isolates of Penicillium digitatum in citrus packinghouses
E. Pérez , O. Blanco, C. Berreta, I. Dol and J. Lado
Postharvest Biology and Technology, Volume 60, Issue 3, June 2011, Pages 258-262
2011
บทคัดย่อ
The extensive use of imazalil (IMZ) in Uruguayan citrus packinghouses to control Penicillium spp. favored the selection and proliferation of resistant isolates. With the aim of detecting Penicillium digitatum biotypes that are not controlled by commercial doses of IMZ, the IMZ concentration within amended potato dextrose agar (PDA) plates was adjusted to 1.0 mg L−1IMZ. This concentration allowed the detection of resistant isolates that were not controlled by commercial applications of 3.0 g L−1IMZ. These isolates were able to grow in fruit with IMZ residues of 0.92 and 3.08 mg kg−1. Therefore, environmental monitoring of facilities where commercial dip applications containing 3.0 g L−1IMZare employed, should be done with 1.0 mg L−1of IMZ in Petri dishes. We can conclude that use of IMZ in postharvest applications of 3.0 g L−1remains effective to control wild Uruguayan P. digitatum isolates but not for resistant ones. A survey of 26 P. digitatum isolates collected in Uruguay indicated IMZ resistant isolates occurred in packinghouses and not in citrus groves.