Efficacy of ethanol in postharvest benomyl-DCNA treatments for control of brown rot of peach.
Feliciano, A.; Feliciano, A. J.; Vendrusculo, J.; Adaskaveg, J. E.; Ogawa, J. M.;
Plant Disease Year: 1992 Vol: 76 Issue: 3 Pages: 226-229 Ref: 7 ref.
1992
บทคัดย่อ
Ethanol at concn of more than or equal to 30% gave improved control of postharvest brown rot (Monilinia fructicola) of peach by benomyl + DCNA [dicloran] mixtures in 1-min dip treatments. The model of the regression analyses was significant (Pless than or equal to 0.01) and linear (r2 = 0.97). The slope of the equation for the incidence of brown rot and the concn of ethanol with fungicide was similar, but the Y intercept and midpoint values were lower than when ethanol was used alone. Control of brown rot was best with 70% ethanol, but shrivelling of fruit epidermis from dehydration was greatest at this concn. Addition of 30% ethanol to a benomyl-dicloran mixture reduced disease incidence and fungal sporulation after 6 d of incubation. Fruit were commerically acceptable, with only limited dehydration. Slopes of each linear equation were similar (Pmore than or equal to 0.05) for 0.5-, 1.0- and 2.0-min dipping periods as related to the incidence of brown rot and the concn of ethanol (0, 30, 50 or 70%) in a benomyl-dicloran mixture. The incidence of brown rot vs. dipping time (5, 10, 20 and 30 sec) in a benomyl-dicloran mixture suspended in 30% ethanol was significant (P less than or equal to 0.05) and linear (r2 = 0.92). Less disease accompanied longer dipping periods. When fruit were inoculated with conidia of M. fructicola and incubated for 4-48 h before being dipped in a benomyl-dicloran mixture suspended in 30% ethanol, lesions after 6 d were smallest in fruit treated less than or equal to 12 h after inoculation. The regression of lesion diameter vs. delay of treatment after inoculation was linear (r2 = 0.91). In canned peach flesh, residues between treatments with or without ethanol differed by less than or equal to 0.54 micro g/ml for benomyl and less than or equal to 0.29 micro g/ml for dicloran, in the peach syrup, differences between treatments were less than or equal to 0.36 micro g/ml for benomyl and less than or equal to 0.11 micro g/ml for dicloran residues.