A composition and method to mitigate plant autophagy and/or apoptosis of newly developing cells in plants grown under environmentally stressful growing conditions, such as high temperature. Exogenous application of a cytokinin, preferably kinetin, to either the roots or the foliage (i.e., flowers and leaves) of plants has been discovered to overcome, or at least substantially mitigate, autophagy when applied during or just prior to flowering. Experimental results indicate that high temperature-induced autophagy, and subsequent new cell apoptosis, is the result of a deficiency of cytokinin in the plant tissues. The application of low concentrations of potassium together with the cytokinin appears to provide a synergistic effect by amplifying the effect of the cytokinin to lessen autophagy and increase crop productivity.