Why is my young papaya tree growing smaller and smaller on the top? It is about 8’feet tall and 1 year old. Grows in Florida in full sun.
How's your water management? Are you irrigating adequately to support new growth?
Nutritional deficiences are also a possibility. Do you fertilize, or build soil fertility with compost and mulch?
Papaya are susceptible to a number of pest and disease issues that can cause stunting of the new growth at the top. Do you observe any bugs, discoloration, patches or spots on the leaves or on the stem. Or do you over water and create conditions for root and crown rot.