Fertilizer Application, Inherent Fruitfulness, and Rainfall Affect Flowering of Longleaf Pine

In a given year, the number of female strobili produced by individual trees of Pinus palustris Mill. in heavily thinned and cultivated stands was influenced, in descending order of importance, by (1) inherent ability to flower, (2) spring and early summer rainfall in the year of flower bud formation, (3) annual rate of fertilizer application, and (4) flowering 2 years earlier. Collectively, these factors and their interactions accounted for 66 percent of the variation in flowering in central Louisiana during 1961 to 1965.