Secretion of GH by the pituitary into the bloodstream stimulates the liver to produce another hormone called insulin-like growth factor I (IGF-I). IGF-I is what actually causes tissue growth in the body. High levels of IGF-I, in turn, signal the pituitary to reduce GH production.
Site and Spacing. 1  The pawpaw is a small tree that typically grows to about 20 feet high and less broad. 2  In an orchard setting, tree centers should be at least 10 feet apart. Row widths depend on the size of tractors and equipment -- 20 foot rows may be a minimum width.
You are Here > Fruit Trees > Paw Paw Trees >. Alternative Views: The native American Paw Paw tree is a cold hardy fruit tree that grows all the way northwards to Ohio, Indiana, and Illinois. The Paw Paw fruit is soft and tasty like banana custard and pleasingly aromatic like ripe bananas.