No, the TX retirement income is not taxable in KS.  

Actually, KS doesn't even tax their residents on that type of income:

The amount you received as retirement benefits from the Kansas Public Employees Retirement System is not taxable on your Kansas return. The retirement benefits must be included in your federal adjusted gross income before it can be subtracted on your Kansas return. Retirement benefits taxed on your Federal return must be entered on Kansas Schedule S, Part A.