The respiratory pattern of broccoli bud clusters treated with N6‐benzyladenine at harvest or at daily intervals thereafter was similar to that of at‐harvest‐treated broccoli. The treatment effect did not diminish with time but was conditioned by the degree of physiological degeneration of the tissue prior to treatment. Respiration quotients indicated that the rate of oxidative decarboxylation and phosphorylation was reduced in tissues treated with N6‐benzyladenine. Higher organic phosphorus content was observed in treated tissue, and 2,4‐dinitrophenol overcame the N6‐benzyladenine‐induced respiration inhibition. It is suggested that the mode of action of phytokinins on respiration and senescence inhibition was due to a conservation of adenosine triphosphate in treated tissue.