The origin of the large α-particle production cross sections in systems involving weakly bound ⁷Li projectiles has been investigated by measuring the cross sections of all possible fragment-capture as well as complete fusion using the particle-γ coincidence, in-beam, and off-beam γ-ray counting techniques for the ⁷Li + ⁹³Nb system at near Coulomb barrier energies. Almost all of the inclusive α-particle yield has been accounted for. While the t-capture mechanism is found to be dominant (∼70%), compound nuclear evaporation and breakup processes contribute ∼15% each to the inclusive α-particle production in the measured energy range. Systematic behavior of the t capture and inclusive α cross sections for reactions involving ⁷Li over a wide mass range is also reported.