Which abiotic factor is not essential for early growth of the plant but growth is sustained only in its presence?

Name the abiotic factor which is not essential for early growth of the plant but growth cannot be sustained in its absence?

Name the abiotic factor which is not essential for early growth of the plant but growth cannot be sustained in its absence?

Which is essential for the growth of tip?

Which is essential for the growth of root tip

Which is essential for the growth of root tip?

Which abiotic factors are responsible for growth of seedlings?