Hydroponic Tomato Growth:
An Interactive Decision Support System

Introduction

The Decision Support System is an interactive Java program which allows the users to explore the optimal values of solution pH, electrical conductivity, air and root temperature, and relative humidity depending on the growth stage of the plant and certain climatic conditions. The user is presented with a user-interface and allowed to manually vary the values of the growing parameters as well as the growth stages. As these adjustments are made the algorithm decides whether there is a risk of the crop not being high yield/high quality. The algorithm also gives feedback as to which factors are the most critical and should be adjusted first.

Running The Software

The software is a Java Applet. These kinds of programs are commonly found on the internet and your browser may already be able to run this program, especially if it is a newer version. If not, we recommend you download either Netscape Navigator 6.0 or Internet Explorer 5.0.

Growth Stages

There are five growth stages considered here and defined below, (by CropKing, Inc. 1993). You will be able to select the stage that represents your tomato plant(s) the best.

1) Germination and early growth stage: starts from the time of sowing the seeds until the seed's coat breaks and the roots emerge.

2) Seedling Stage: starts from the time the seed's coat breaks and the roots emerge until they are transplanted into growing media.

3) Vegetative stage: starts from the time the seeds are transplanted into the growing media until the first flower opens.

4) Early fruiting stage: starts from the time the first flower opens until the first fruit is picked.

5) Mature Fruiting stage: starts from the time the first fruit is picked until the termination of the crop.

Other Climatic Factors

Other climatic factors affect optimal growing parameter values. These are, whether it is night or day and whether it is cloudy or sunny.

How To Use The Program

Here is a picture of what the software will look like in your browser. You may use the text boxes or the sliders to adjust all of the growing parameters. The checkboxes near the top of the page allow you to choose the growth stage of interest. The 'traffic lights' tell you whether the parameters are optimal or not.

The text area at the bottom tells the user what parameters need to be modified in order of importance. The numbers beside the 'traffic lights' are a measure of how optimal the level is. The maximum level is 100 and the minimum is 0. It is important to note that these numbers reflect the degree to which an expert grower would want that particular level of the key parameter. These level do not necessarily communicate the chance of success or failure of the final crop.