Density fluctuations in the solar wind can affect the coherent plasma emission process driven by beams of energetic electrons, which produces various types of solar and interplanetary radio bursts. Here we employ fully kinetic electromagnetic particle-in-cell simulations to investigate such effects on various branches including the fundamental (F) and harmonic (H2, H3, and H4) radiations. We varied the amplitudes of density fluctuation (ΔN, changing from 0.0, 0.02 to 0.05) for both fast-beam (ud = 0.5c) and slow-beam (ud = 0.25c) cases. We conclude that larger density fluctuations broaden the ω and k ranges of F emission and suppress higher-harmonic radiation due to the enhanced scattering of the primary Langmuir waves, whereas a faster beam promotes conditions favorable for harmonic generation. This work provides novel understanding of the observed suppression and spectral broadening of solar radio bursts in the turbulent solar wind.