The effectiveness of pyrimethanil to inhibit germination of Penicillium digitatum and to control citrus green mold after harvest

Pyrimethanil (PYR) has recently been approved for postharvest use on citrus fruit to control green mold, caused by Penicillium digitatum. he EC50 of PYR to inhibit germination of P. digitatum spores was 0.2–0.4 mg/L and was similar from pH 4 to 7. Green mold on citrus fruit as reduced more than 90% by PYR at 500 mg/L or higher applied by immersing for 30 s or drenching the fruit, while its application in wax ver rotating brushes at 1000 or 2000 mg/L reduced green mold about 65%. Control of sporulation by PYR in aqueous solutions was better han the same concentration applied in wax, but it was inferior to imazalil. An imazalil-resistant P. digitatum isolate was controlled by PYR. he addition of sodium bicarbonate improved PYR performance. PYR was not compatible with chlorine. An increase in the temperature of the PYR solution slightly but significantly improved its effectiveness ◦ o control green mold, although its residues on fruit were greatly increased by heat; they approximately doubled for each 5 C increase in olution temperature above 30 ◦C. PYR was very effective when applied up to 24 h after inoculation, but much less effective when it was applied efore inoculation. PYR effectively controls green mold and can be useful to control isolates of P. digitatum resistant to other fungicides. ublished by Elsevier B.V.