Improvement of Vegetable Quality and Water and Fertilizer Utilization in Low-Tech Greenhouses Through a Decision Support Management System

ABSTRACT A comprehensive decision support management system for the cultivation of six vegetable crops (tomato, cucumber, melon, eggplant, pepper and lettuce) in low technology plastic-covered greenhouses is described. The system consists of: (1) an irrigation and nutrition management module that defines the daily water and fertilizer requirements of each crop primarily on the basis of information derived from a simple evaporimeter, (2) a diagnostic expert system for the identification and confrontation of pests, diseases and nutritional disorders, and (3) a number of information modules that provide the grower with advice on specific cultivation procedures (e.g., propagation, greenhouse preparation, plant care, harvest, post-harvest packaging, storage and marketing). The system utilizes a core of knowledge base (core KB), which contains information common to all crops, supplemented by individual KB's containing knowledge that is specific to each particular crop. This interaction of core and crop-specific KB's enables maximum economy of information storage and minimizes redundancy. The system is simple to operate and does not require hardware other than a personal computer and a simple, inexpensive evaporimeter. It has been tested over a period of three years during which time a saving of 15–30% in irrigation water and fertilizer consumption was achieved.