The angular distribution of the reaction 6 Li͑d , ␣͒ 4 He at deuteron energies below 100 keV and the total cross section as well as the angular distribution of the reaction 10 B͑d , p 0 ͒ 11 B at energies below 350 keV have been measured. Based on our experimental results and data of other authors, the reaction mechanism has been studied in a wide energy range, relevant for astrophysical applications. It has been found that in both cases broad resonances in the compound nuclei play the key role for the description of the excitation functions. The long-standing problems of describing the angular distributions could be solved for both reactions by assuming a coherent superposition between resonant and direct reaction amplitudes. A theoretical approach allowing for coherent calculations has been developed. Some astrophysical implications are discussed.