I don't know how the rules are in Texas but I am in Tennessee and thought about getting a applicators license too.
Much to my dismay I discovered that you either had to:
1) Be verified
as having worked for a licensed applicator for at least 2 years...or...
2) Have a 4 year college degree in a related field (horticulture, arborist, etc.) ...or...
3) Been previously licensed yourself in another state-also verifiable
I can get the study materials but CANNOT take the test if I can't meet one of the three requirments listed above.
Check the Texas Department of Agriculture website (provided they have one).
Tennessee has one and that is where I got this info.
Good Luck Schlepie!