Abstract: A growth regulation process involving certain phosphonic acid compounds having the general formula: ##STR1## The growth regulation process of the present invention relates mainly, though not entirely, to the inducement of an ethylene response or ethylene-type response in plants and part thereof including, but not limited to, stems, roots, leaves, flowers, buds, and harvested as well as unharvested fruit.The method of the present invention produces a wide variety of plant growth responses including:1. Increasing yields2. Auxin activity3. Inhibition of terminal growth, control of apical dominance, increase in branching and increase in tillering4. Changing bio-chemical composition of plant or portions thereof5. Abscission of foliage, flowers and fruit6. Hastening ripening and color promotion in fruit7. Increasing flowering and fruiting8. Abortion or inhibition of flowering and seed development9. Prevention of lodging10. Stimulation of seed germination and breaking of dormancy11. Resistance to freeze injury12.