HORTICULTURAL EXPERIMENTS AT SAN ANTONIO. 3 
records kept by the Weather Bureau at San Antonio for a much 
longer period will show that the mean rainfall for the last seven years 
is shightly below what is to be ordinarily expected. The year 1909, 
which was the driest that has been known during the observed period 
(more than 40 years), was followed by two years when the rainfall 
was considerably below normal. In spite of the adverse conditions 
during this period, the orchards came through with no loss of trees 
which could be traced directly to a lack of moisture. 
TaBie I].—Annual precipitation at the San Antonio Experiment Farm, 1907 to 1913, 
inclusive. 
suas || Ene haps 
ay: Precipi- || xe Precipi- i Precipi- 
Year. tation. | Year. tation. Year. tation. 
Inches. ] | Inches. Inches. 
ROU ampere as Seb beth ZOXOSH ttl QLOLe ae ae ee Ae | ZOSOZE IGT SS Co eae eels eee 36. 71 
TOURS ene or Ae | ESTE MOI a ee eer, oA eS 23. 93 — 
Re en rne WS ee sh | IUD SIMEE I WME as 2 Soe me Seale | 26. 37 Meanii. sth sae 24. 66 
THE SOIL CONDITIONS. 
San Antonio lies in the southern extension of what is known as the 
Black Prairie region, or the ‘‘ Black Lands’? of Texas, and near the 
: ) ) 
northern edge of an 
area known geograph- PAR, Ae ee 
Sree a AW 
ically as the Rio 
Ln 
% 
Grande Plain. The §,0 
soil is mostly the re- < 
sult of the weathering i : g n : 3 g < ok 
of limeston £ rocks of Fic. 1.—The mean monthly rainfallat San Antonio, Tex., from 1891 to 
the Upper Cretaceous 1913. (Compiled from the records of the United States Weather 
period. Recent allu- ?™"? 
vial deposits have been washed down from the higher lands north- 
west of the city, resulting in modifications through the addition of 
coarser material. The typical soil is a heavy black or brownish loam. 
The lime content of the soil is unusually high, the proportion of 
carbonate of lime in the upper 12 inches ranging from 7 to 23 per 
cent. This lime occurs in the soil both as a finely divided material 
and as gravelly concretions. In the former condition it is generally 
dark colored through staining by decomposed organic matter, while 
in the latter condition it is usually white 
This excess of lime is believed to be the cause of one of the most 
serious disorders of fruit trees that have been encountered in the experi- 
mental work reported in this paper. The chiefsymptom is a yellowing 
of the leaves, and in the later stages the leaves drop and the tree 
gradually dies. Often in less severe cases the tree may continue to 
live and make a poor growth and bear some fruit for several years 
yo 
