Abstract
Optimum crop yield is greatly affected by proper planting and sowing times. The objective of this research was to develop an algorithm that uses the heat unit concept to determine the most suitable planting times for vegetable crops. The developed algorithm was programmed in a database environment with sample climatic data for the Kingdom of Saudi Arabia. The model was tested by validation (comparison to experts' estimations), verification (statistical comparison to formal published data), and evaluation (by professionals, landowners, and farmers). The overall results of the model were highly acceptable. The model needs more verification and validation in different environments and with various crops. (C) 2012 Elsevier B.V. All rights reserved.