Phytoparasitica (1996) 24, p. 78 (Towsen et al.)
Estelle Towsen, Sandra vanWyngaardt, Jan A. Verschoor, Lise Korsten and Jan M. Kotzé (1996)
Monitoring Bacillus subtilis populations in preharvest biocontrol programs on avocado
Phytoparasitica 24 (1), 78-78
The third World Avocado Congress, October 22-27, 1995, Tel Aviv, Israel, lecture
Abstract: Pre- and postharvest biological control of avocado fruit diseases has been investigated at the University of Pretoria, South Africa, for the past 8 years. Postharvest application of antagonists provided more effective disease control than preharvest application, presumably due to impediment of antagonist survival and activity under field conditions. Poor antagonist survival under field conditions can thus affect the efficacy of the biocontrol program negatively. Therefore, monitoring antagonist survival is of prime importance in ensuring effective disease control. Various detection methods, e.g. electron microscopy (EM), leaf imprinting and dilution plating, were evaluated for determining the persistence of Bacillus subtilis biocontrol agents in field spray programs. EM studies showed an increase in bacteria on the leaves, in comparison with a decrease observed with the leaf imprint and dilution plate techniques. Since none of these techniques facilitated rapid and accurate screening of antagonists, monoclonal antibodies (MAB) were raised against the B. subtilis isolate used most commonly. The ELISA technique was optimized and utilized to monitor different antagonist concentrations under greenhouse conditions. MAB are at present being evaluated for field surveillance of antagonist survival as part of the preharvest biocontrol program on avocado.
Database assignments for author(s): Lise Korsten
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Bacillus subtilis (antagonist) | South Africa |
