ABSTRACT


Ada Tomic1, Gaston Apablaza2, Anthony Wylie3
 
Benlate, Dimanin and Dowcide A fungicides were tested under in vitro and in vivo conditions to control Botrytis cinerea and Penicillium expansum in Beurre D'Anjou pears.
Fruit inoculation was done artificially by perfonting the pears with a glass rodin five places over the equatorial zone, and placing sorne fungus mycelium in eachhole. In the in vivo test the fungicides were applied either by immersion or sprayingthe fruit.
In the in vivo test the fungicides were applied either by immersion or spraying the fruit.The in vitro test was done according to the Coyier agar test. Treatments used were: Benlate 100 - 300 - 500 - 800 ppm; Dimanin 800 - 1,200 - 1,600 y 2,000 ppm, y Dowcide A 0.15 - 0.80 - 1.60 - 2.0%. In the in vitro test Benlate 500 and 800 ppm, and Dimanin 2,000 ppm completely inhibited Botrytis cinerea; Dowcide A 1.6 and 2.0% had a similar effect over Penicillium expansum. A good control in the in vivo test was observed with Benlate 500 and 800 ppm for Botrytis.Similarly effective control was obtained with Dowcide A 1.2 and 2.0%. Application of the fungicides by immersion gave a better level of control than spraying in all treatments. Only Dowcide A gave a similar control for Penicillium with both systems of application. A negative correlation was found for fungicides performance between the in vitro and in vivo tests.
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1Ing. Agr. Ministerio de Agricultura Servicio Agrícola y Ganadero (SAG). Casilla 322, La Serena, Chile.
2Ing. Agr., M. S., Profesor Cátedra de fitopatología General, Facultad de Agronomía, Universidad católica de Chile.
3Ing. Agr., Ph. D., Profesor Cátedra de Fruticultura, Facultad de Agronomía, Universidad Católica de Chile. Casilla 114-D, Santiago, Chile.