A neural-net approach to specifying an expert control policy for the g
reenhouse environment is proposed. The main idea is to utilize data ro
utinely collected in a commercial greenhouse, rather than to interroga
te the grower verbally. The expert should, however, specify which inpu
t information seems important. Two automatically collected data sets (
Avignon, France, and Lake City, Florida) were used to test the propose
d method. Comparison of the temperature operating-point policies for t
omato in these two greenhouses showed that the general decision patter
n is similar, but differences of several degrees are evident. This met
hod is thought to be more objective and less time consuming than the t
raditional expert system approach. Ir requires, however, a considerabl
e amount of data.