Plant behavior and response to environmental stimuli has tremendous importance in science and agriculture. In particular, a plant's root continuously senses changes in the environment, and responds in ways that optimize dynamically different essential parameters like its stability, and adequate food and water supplies. Some of the plant behavioral changes in response to environmental changes, like water shortage, can be reversible, and after certain 'stress' time, the plant can get back to its normal behavioral patterns. In other cases, the plant behavior after the stress stimulus ends, is changed, due to effects on internal mechanisms, facilitating long-term behavioral changes. The main aim of this work is to derive a preliminary physical model and analysis tools to quantify the behavioral changes of a plant in response to a stimuli. To demonstrate the model, we examined, without loss of generality, the change in plant growth rate in response to electrical simuli. We showed how the suggested plant behavioral model can assist in computational analysis of short and long term plant response to changing stimuli, construct a common baseline for comparison with other stimuli, and derive new quantitative measurements that can be correlated with internal plant mechanism and assist in assessing behavioral plant patterns and in the design of more efficient agricultural technologies.