Residue Level, Persistence, and Storage Performance of Citrus Fruit Treated with Fludioxonil
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- 作者：Mario Schirra ; Salvatore D'Aquino ; Amedeo Palma ; Salvatore Marceddu ; Alberto Angioni ; Paolo Cabras ; Barbara Scherm ; and Quirico Migheli
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2005
- 出版时间：August 24, 2005
- 年：2005
- 卷：53
- 期：17
- 页码：6718 - 6724
- 全文大小：343K
- 年卷期：v.53,no.17(August 24, 2005)
- ISSN：1520-5118
文摘
The potential of postharvest dip treatments with fludioxonil (FLU) (a synthetic analogue of the bacterialmetabolite of pyrrolnitrin), in controlling postharvest decay caused by Penicillium digitatum andPenicillium italicum of citrus fruit was investigated in comparison with the conventional fungicide imazalil(IMZ). The ultrastructural changes of fruit epicuticular wax was investigated as a function of waterdip temperature, and the possible role of these changes was related to residue accumulation underFLU treatment. Residues retained by fruit were determined as a function of fungicide concentration,dip temperature, and fruit storage conditions. Scanning electron microscopy analysis revealed thatfruit dipping in water at 30 or 40 
C did not cause differences in cuticular wax's ultrastructure incomparison to control fruit, while treatments at 50, 55, or 60 C caused the disappearance of waxplatelets, resulting in relatively homogeneous skin surface, due to partial "melting" of epicuticularwax. Residues of FLU in fruit treated at 20 or 50 C were significantly correlated with the doses offungicide applied. When equal amounts of fungicide were employed, the residue concentrations werenotably higher (from 2.6- to 4-fold) in fruit treated at 50 C than in fruit treated at 20 C. The dissipationrate of FLU in "Salustiana" and "Tarocco" oranges was lower in fruit subjected to treatment at 50 C.The minimal FLU concentration for almost complete decay control in artificially wounded fruit during7-d storage at 20 C was 400 mg/L active ingredient (ai) in fruit treated at 20 C and 100 mg/L ai infruit treated at 50 C. Results on nonwounded Tarocco oranges subjected to 3 weeks of simulatedquarantine conditions at 1 C, plus 6 weeks of standard storage at 8 C and an additional two weeksof simulated marketing period (SMP) at 20 C revealed that almost complete decay control with FLUapplications of 100 mg/L at 50 C and 400 mg/L at 20 C resulted in ca. 0.8 mg/kg FLU fruit residues,in agreement with results on wounded citrus fruit. When equal concentrations and temperatures wereapplied, FLU treatments were as effective as IMZ. In vitro trials showed a low sensitivity to FLUagainst P. digitatum and P. italicum isolates. MIC values for the complete inhibition of myceliumgrowth were 
100 
g/mL, while ED50 values ranged from 0.1 to 1 g/mL for P. digitatum and from1 to >100 g/mL for P. italicum. The latter result suggests that care should be taken to avoid exclusiveapplication of FLU in a sustainable program for management of fruit decay. However, integratingfungicide application and hot water dip may reduce the possibility of selecting fungicide-resistantpopulations of the pathogen, by increasing the effectiveness of the treatment.Keywords: Citrus fruit; disease control; hot water dip; fungicide treatments; fludioxonil; imazalil;residues; fungicide resistance, phenylpyrrole
C did not cause differences in cuticular wax's ultrastructure incomparison to control fruit, while treatments at 50, 55, or 60 C caused the disappearance of waxplatelets, resulting in relatively homogeneous skin surface, due to partial "melting" of epicuticularwax. Residues of FLU in fruit treated at 20 or 50 C were significantly correlated with the doses offungicide applied. When equal amounts of fungicide were employed, the residue concentrations werenotably higher (from 2.6- to 4-fold) in fruit treated at 50 C than in fruit treated at 20 C. The dissipationrate of FLU in "Salustiana" and "Tarocco" oranges was lower in fruit subjected to treatment at 50 C.The minimal FLU concentration for almost complete decay control in artificially wounded fruit during7-d storage at 20 C was 400 mg/L active ingredient (ai) in fruit treated at 20 C and 100 mg/L ai infruit treated at 50 C. Results on nonwounded Tarocco oranges subjected to 3 weeks of simulatedquarantine conditions at 1 C, plus 6 weeks of standard storage at 8 C and an additional two weeksof simulated marketing period (SMP) at 20 C revealed that almost complete decay control with FLUapplications of 100 mg/L at 50 C and 400 mg/L at 20 C resulted in ca. 0.8 mg/kg FLU fruit residues,in agreement with results on wounded citrus fruit. When equal concentrations and temperatures wereapplied, FLU treatments were as effective as IMZ. In vitro trials showed a low sensitivity to FLUagainst P. digitatum and P. italicum isolates. MIC values for the complete inhibition of myceliumgrowth were 100 g/mL, while ED50 values ranged from 0.1 to 1 g/mL for P. digitatum and from1 to >100 g/mL for P. italicum. The latter result suggests that care should be taken to avoid exclusiveapplication of FLU in a sustainable program for management of fruit decay. However, integratingfungicide application and hot water dip may reduce the possibility of selecting fungicide-resistantpopulations of the pathogen, by increasing the effectiveness of the treatment.Keywords: Citrus fruit; disease control; hot water dip; fungicide treatments; fludioxonil; imazalil;residues; fungicide resistance, phenylpyrrole