TOMATEX an expert system field prototype for tomato crop. It includes five subsystems namely: diagnosis, treatment, irrigation, fertilization and post-harvest. These functions have been carefully chosen such that they can provide f rmers with advice and recommendations about the different agricultural operations that improve the crop productivity.

Eight domain experts in different specialties covering all the above mentioned application functions have been involved in developing this prototype.

The prototype is implemented using special expert system software called Knowledge Representation Object Language KROL, developed at the Central Laboratory of Agriculture Expert System (CLAES ). The system is running on personal computers under window 95 environment, which facilitate subsequent porting to run on the Internet to be accessible worldwide.

The main goal of this function is to obtain a schedule for irrigation of a particular plastic tunnel. An Irrigation schedule demonstrates the water quantity related to each time instance. The calculated water quantity s adapted according to several plastic tunnel characteristics concerning, soil, water, and weather as well as some other special farm parameters such as intensity of plants, efficiency of drainage system, use of mulch, etc. The output from this function s the irrigation from the cultivation date until harvesting. This schedule includes the water quantity, irrigation intervals, and irrigation date.

The main goal of the fertilization function is to determine the fertilization requirements for the cherry tomato crop before and after transplantation. Fertilization requirements include several aspects: fertilizer type, quantity, fertilizer application method, and the intervals between fertilizer applications.

 In general the output of fertilization function should take the form of table. This table explains, for each stage, the fertilization type, quantity, unit of each fertilizer, and t e application method for each fertilizers (whether they should be added to the irrigation water or they will added as foliar fertilizers). In addition, the output should include some general recommendations to the users.

There are two purposes of this subsystem:

 1. It concludes the causes of the user complaint.

2. It verifies the user assumption, if he/she knows the causes of his/her complaint.

The output of this subsystem is as follows:

· If there are user complaints, the output is the causes (disorders) of these complaints. Each disorder must have a certainty factor. The certainty factor of the confirmed disorders is either “likel ” or “most likely”.

· If the user knows the causes of the abnormal observations, and he wants a treatment of the assumed disorders, this subsystem must verify the user assumption. Diagnosis subsystem displays the user bout the unconfirmed disorders only.

The purpose of this subsystem is to advice the user about the treatment operation of the infected plant.

The output of this subsystem is the treatment schedule. The output includes a complete specification about the treatment operation: disorder name, material name, material quantity, mode of entry, method of application, the to l used in the treatment operation, application time, and advice. Since the treatment subsystem should takes into consideration the seriousness of the affected disorder, it orders the treatment operations according to the disorder seriousness degree.

The purpose of this function is to provide the users with recommendation and advises concerning the following:

• Keeping the product in a good conditions, and high quality.
• Harvesting methods.
• Preparing package for either local or external consumption.

The output of this function will take the form of hypertext, images, and video, using the multimedia technology. The system provides description concerning the postharvest activities namely: harvesting, sizing, pre cooling, c vering, packaging, storing, and transporting.

For more information mail to <hesham@esic.claes.sci.eg>