The Effects of Fertilization on Diameter Growth in Dense Stands of Ponderosa Pine in Arizona

TitleThe Effects of Fertilization on Diameter Growth in Dense Stands of Ponderosa Pine in Arizona
Publication TypeThesis
Year of Publication1976
AuthorsLeech, GR
DegreeMS
UniversityUniversity of Arizona
Abstract

In 1961, fifty 1/5-acre plots were established near Blue Mountain in Arizona by Professor R.F. Wagle for the purpose of testing a selected group of fertilizers, a herbicide and a growth hormone in overcoming stagnation in Ponderosa pine stands. Thirteen treatments were applied at random on the plots. Nitrogen, phosphorus, potassium, fenuron, gibberellic acid, along with a select group of microelements were applied on the plots. Tree growth was measured at the end of each growing season by use of a dendrometer or growth band. The growth band measured circumference growth to 0.01 inches. Diameter measuements were made in 1961 and 1973 using a diameter tape. Diameter measurements were estimated to 0.01 inches. The data were analyzed using Student-Newman-Kuels’ test. The analyses were performed at the 95% confidence level. The results indicated that stagnation cannot be broken using fertilizers without thinning when the stand and site characteristics of the type present in this study exist.