The decision support system for IPM of prune brown rot (DSS-PBR) is newly developed internet-based system by Dr. Themis J. Michailides’s group at University of California, Kearney Agricultural Center. This system primarily emphasizes on brown rot disease in prunes, but it could extend to brown rot of other stone fruit after further researches. The DSS-PBR could help growers, farm advisors and fruit industry in decision for brown rot management. Currently, this system could help users to determine the timings of fungicide application, irrigation and fruit thinning for disease control. In the future, the system can help users to determine the short- and long-term management strategies based on the specific orchard situations.
This system had been developed with results of field and laboratory experiments conducted by Dr. Michailides’s group. The researches mainly focused on the quantitative relationships among pathogen, host and environments. The changes in bloom and fruit susceptibility to infection over the growing season are basically clear. Full bloom is the most susceptible stage to infection causing blossom blight (please refer to the figures), and the most susceptible fruit stage to latent infection was at before pit hardening (please refer to the corresponding figures). These seasonal patterns of bloom and fruit susceptibility to infection are useful information in decision for disease management. Environments including temperature and wetness duration quantitatively affect incidence of blossom blight (please refer to the figures) and latent infection. Increase in inoculum concentration also quantitatively promoted the disease development (please refer to the figures). Seasonal patterns of wetness duration (in hours) leading to different risk levels of latent infection were also determined (please refer to the corresponding figures).
Decision for disease management should, therefore, consider the above quantitative relationships to determine the optimal control strategies. The principle of IPM for prune brown rot is to consider humans effects on the disease triangle (host, pathogen and environment), and to determine how human (grower) can act on this triangle to reduce the risk of disease development and yield losses. Application of this principle in the DSS-PBR development is summarized in a diagram (please refer to the diagram ). However, the DSS-PBR does not require the users to do many calculations. The main function of this system is to provide the users with only three statements: NOTE, WARNING and RECOMMENDATION, which were based on calculations and model applications by the system developer.
The main features of the system are: 1) feedback between system developer and users; 2) dynamic decision supports over the growing season, namely, decision supports will be given at different stages; and 3) accumulation of information for system improvement and intensive researches; and 4) orchard-based decision supports, meaning the information on both disease and control history and decision making are for the specific orchards. Therefore, growers are encouraged to become the members of this system for using and improving the system. Very simple approaches will be used. (Please refer to the left site of the age). Furthermore, providing the system with basic and required information about the disease development in the specific orchards is an obligation of the system users, that is also not complicated to perform. And the growers will be benefited from obtaining more precise disease prediction and decision supports.
Any comments, suggestions, criticisms, and other information about using this system are welcome. The information could be sent to Dr. Themis J. Michailides as the following address:
Dr. Themis J. Michailides