Note: Program is currently under revision. Using the Arkansas DD50 program and selecting Clay County will provide reasonable estimates for the time being.

Welcome to the Missouri Rice Degree Day 50 (DD-50) webpage.

If you are a rice farmer in southeast Missouri, you will be able to enter information about your field and receive a report with predictions and recommendations based on local weather. This program uses maximum and minimum daily air temperatures to predict when rice growth stages will occur in a field. The program assumes rice growth will not occur with average temperatures below 50 degrees F. The objective of this program is to improve the timeliness of rice management decisions by utilizing temperature data from the commercial agriculture weather station network. DD-50 reports generated early in the season are based on long-term weather averages. As the season progresses, new reports can be made with updated rice growth predictions based on weather that has occurred in the season.

To generate a DD-50 report for your rice field, begin by clicking the "Start report" button at the bottom of this page. A new screen will appear with the following blank boxes in which you should enter your information.

  1. Field. Enter the field name in the appropriate box.
  2. Variety and Weather Station. Scroll through the choices of rice varieties and weather stations by clicking on the down arrow in the right corner of each box. Some counties have more than one choice of weather stations. New rice varieties will be added to the list as calibration research is completed.
  3. Emergence Date. Enter the number of the month and day that the rice emerged. We define rice emergence as the date that 10 one-leaf rice plants per square foot are present in a field.
  4. Name and Address. If you want to have your name and address appear on each report, enter this information in the boxes on the bottom of the screen. This is an optional step. We do not use this information in the model.
  5. SUBMIT Query. Click this button when you have completed the boxes.

The DD-50 report will provide the following information:

  • Various weed control options and herbicide cutoff dates
  • when to apply preflood nitrogen and flood the field (beginning tillering)
  • When to check plant area for adequate nitrogen fertility at mid-tillering
  • The recommended nitrogen fertilization rate and timing for the variety
  • When to begin scouting for insects and diseases and control recommendations
  • Midseason — beginning jointing, time to check plant area, and time to apply mid-season nitrogen
  • Time of 50% heading
  • When to stop pumping
  • When to pull the flood and when to harvest

After you submit a query, a report will appear on your screen. Use the print function of your internet browser to print the report. To submit a new field, click on the "Back" button in your browser.

A precaution: The accuracy of the growth stage predictions should be verified by the grower at three times during the season.

  1. Beginning tillering
  2. Beginning internode elongation
  3. At 50% heading

To view illustrations of these growth stages, click on the blue text in your report, where available. Long-term temperatures are replaced with actual measurements each day. If the actual daily temperatures are significantly hotter or colder than the long-term averages in a given season, the accuracy of the predictions should be improved by creating new reports.