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.
Pawpaw Trees. The Paw Paw is a true native American fruit tree indigenous to the entire eastern half of America, from Texas to the Great Lakes and down the east coast to Florida. The Paw Paw is rarely seen and hardly known by recent generations, but was a household name for the pre-baby boomer generations.