The post-infection activity of hydrated lime against conidia of Venturia inaequalis

Summary in the original language of the document

The post-infection activity of hydrated lime against conidia of Venturia inaequalis was evaluated using an in
vitro test system based on isolated apple leaf cuticles. Experiments were conducted at 20°C and treatments
were applied 24 or 48 h after inoculation. Experiments were assessed by counting living primary stromata 72
h after inoculation using fluorescence microscopy and fluorescein diacetate (FDA) as a vital stain. At the
conditions of the in vitro test system hydrated lime had a post-infection activity. Suspension of 5 g l-1 applied
24 h after inoculation (16 h after infection) killed all primary stromata and stopped their further development.
Treatments 48 h after inoculation reduced the number of vital primary stromata to 60% of control.
Treatments with saturated solutions of hydrated lime (pH 12.45) and with KOH solutions of different pH
showed that a pH higher than 12.4 was needed to be 100% effective. Suspensions of calcium carbonate
(6.75 g l-1) had no effect.