In 1976, Dr. Jim Stansel developed the concept, methodology,
and original data for forecasting rice development based on usable
heat units. The methodology was called “DD50". In 1986,
Jack Vawter (TAMUS-Eagle Lake) wrote a DOS-based computer program ("DD50")
based on Dr. Stansel's concept and methodology. The DD50 program uses
current daily maximum and minimum air temperature and historic temperature data
to calculate useable heat units for each day. Historic air temperature
data are used for predicting dates where current temperature data are not
available. These heat units are accumulated from seedling emergence and
used to predict various crop growth stages. These predictions are then
used to make recommendations for scheduling production practices. It has since
been modified and updated by various authors (Jack Vawter, James Woodard,
Kuo-Lane Chen, W.H. Alford, and Jim Stansel), and is used by crop
consultants, extension agents, and rice farmers.
The web-based Rice Development Advisory
(RiceDevA) is a complete rewrite of the DOS-based program. It provides a
much improved user interface, and advanced options for creating, running,
and displaying multiple field growth forecasts for different counties, rice
varieties, and planting/emergence dates.