Let Ψ and Σ be bounded sets of positive kernel operators on a Banach function space L. We prove several refinements of the known inequalitiesfor the generalized spectral radius ρ and the joint spectral radiusρ, where Ψ ( 1 2 ) • Σ ( 1 2 ) denotes the Hadamard (Schur) geometric mean of the sets Ψ and Σ. Furthermore, we prove that analogous inequalities hold also for the generalized essential spectral radius and the joint essential spectral radius in the case when L and its Banach dual L * have order continuous norms.Applying the techniques of [18], Z. Huang proved thatfor n×n non-negative matrices A 1 , A 2 , · · · , A m (see [19]). A.R. Schep was the first one to observe that the results from [11] and [27] are applicable in this context (see 2010 Mathematics Subject Classification. 15A42, 15A60, 47B65, 47B34, 47A10, 15B48.Key words and phrases. Hadamard-Schur geometric mean; Hadamard-Schur product; joint and generalized spectral radius; essential spectral radius; measure of noncompactness; positive kernel operators; non-negative matrices; bounded sets of operators.