28 BULLETIN 1105, U. S. DEPARTMENT OF AGRICULTURE. 



on July 1. So favorable were moisture conditions that pine seeds 

 germinated wherever they were even partially covered. It was a 

 common sight to find vigorous young seedlings emerging from the 

 cracks and decayed places in fallen tree trunks. Xot only were 

 the seedlings at the end of the season more abundant than usual, 

 but they were larger on account of the unusually long growing 

 season and the uninterrupted growth made possible by a continuous 

 supply of moisture. In the spring of 1917, first-year seedlings origi- 

 nating in 1916 had an average root length of 6.4 inches and an ex- 

 treme length of 9.5 inches. Seedlings dug in the fall of 1919 had 

 an average root length of 10 inches and an extreme length of 17 

 inches. The dry period in the foresummer of 1920 was generally 

 considered severe, but a comparison with previous years shows that 

 it was less protracted than in 1909, 1911. 1913, *1916, and 1918. 

 Certain sites suffered a high mortality, but, as a rule, survival 

 was ample. Although the summer rains were light, the records 

 disclose no great loss after the drought of the foresummer was 

 broken. The open winter of 1919-20 favored ground heaving be- 

 cause of the excess of moisture in the form of rain, accompanied 

 by alternate freezing and thawing. Certain sites show a loss of 

 over 50 per cent from this cause, but the average was only about 20 

 per cent, and the consequences were on the whole not serious. The 

 winter of 1920-21 was not only open but dry, in consequence of a de- 

 ficiency of both snow and rain. Such conditions favor winterkilling. 

 Nevertheless the total winter losses averaged only about 20 per 

 cent. All things considered, the period from 1918 to 1921 has been 

 the most favorable one from the standpoint of reproduction that has 

 been experienced since the initiation of records at the Fort Valley 

 Experiment Station, and probably the most favorable in 25 years. 

 Although success is still not definitely assured, the present outlook 

 warrants the expectation of good reproduction on the bulk of the 

 area, which is adequately protected against fire and grazing. 



A survey of the graphs in Figure 2 shows that since 1908 there 

 have been three periods during which the distribution and amount 

 of rainfall have been such as to permit the establishment of pine 

 seedlings in appreciable numbers. They are 1911-12, 1913-1915, 

 and 1918-1920. The minimum interval here considered is 1J years, 

 beginning with normal rains in July and August and continuing 

 without a severe drought during the remainder of the first season 

 and all of the second season. In two instances, however, such con- 

 ditions prevailed during a 2J-year interval. 



During the period covered by the rainfall graphs, good seed crops 

 occurred in 1908, 1909, 1913, and 1918. Since the seed does not 

 germinate until the year after it is borne, the right coincidence be- 



