No you can not.
You have to set it via index, the text is optional not the index.
You can do it by :
crmForm.all.picklist.DataValue = 1; //Any index number valid for a given picklist.
Also how you want to read these values from C# or you need to read the values on Form at clientside only?
crmForm.all.picklist.Options will give you the list of all the picklists then you can loop through to process the values.
If you need it on server side via C# see the code snippet below
Regards,
Chinmay