EXPERIMENTS WITH COCONUT PALMS 6 
The basal fertilizer formula used in plats Nos. 2, 3, 4, 6, and 7 
from July, 1915, to July, 1919, was 6 per cent nitrogen, 8 per cent 
phosphoric acid, and 4 per cent potash. In January, 1920, the per- 
centage of potash was increased to 12 for that and subsequent appli- 
cations. The fertilizers applied to plats Nos. 2, 3, and 4 were the 
same in amount of each of two elements as was given plat No. 6, 
but lacked one element which plat No. 6 received. Plat No. 6 received 
the standard amount of complete fertilizer. Plat No. 7 received the 
same kind of fertilizer as plat No. 6, but in double portion. Applica- 
tions were made semiannually, beginning with a standard rate of 2 
pounds per palm at the first application in July, 1915. Subsequent 
rates per palm per application were Vfa pounds in 1916, 2 pounds 
in 1917, 2y 2 pounds in 1918, 3 pounds in 1919, 4 pounds in 1920, and 
5 pounds thereafter. The final application was made in January, 
1926. Plats Nos. 8 and 9 were fertilized with cow manure and to- 
bacco stems, respectively, supplemented with mineral fertilizers to 
make the total application of nitrogen, phosphoric acid, and potash 
comparable to that given plat No. 6. Since both cow manure and 
tobacco stems show decided variability in analyses the applications 
were only approximately equivalent, and prior to 1920 it is considered 
that plat No. 8 received slightly less nitrogen and more potash than 
were contained in the standard application given plat No. 6. When 
the fertilizer applications were given in full amount in 1921 and 
later, plat No. 8 received at each application 600 pounds of manure, 
11% pounds of superphosphate, and 6 pounds of potassium sulphate, 
and plat No. 9 received 100 pounds of tobacco stems, 2% pounds of 
ammonium sulphate, and 21 1 / 4 pounds of superphosphate. Plat No. 
1 received salt (NaCl) alone. Until 1920 the applications of salt 
equaled in weight the standard fertilizer application. Thereafter 
the amounts per palm per application were 3 pounds in 1920, 3*4 
pounds in 1921 and in 1922, and 4 pounds in 1923 and later. 
The fertilizer was broadcast more or less over the area overhung 
by the leaves. Beginning in 1921, deep furrows were plowed between 
plats prior to applying fertilizer to cut the encroaching roots of 
palms in adjacent plats. In May, 1926, the fertilizer treatments out- 
lined above having been discontinued, new plats were established 
crossing the original plats at right angles, and salt was applied to 
the four palms centrally located in respect to each of the original 
plats. The salt was broadcast at the rate of 5 pounds per palm, and 
the application extended as far as the guard row on both sides. The 
application was repeated in November, 1926, in May and November, 
1927, and in May, 1928. The four palms, the two at either end of 
each of the original plats, which remained untreated, constituted the 
check in the new alinement. The applications of salt were made for 
so brief a period prior to the termination of the record that the 
effect on nut production could have been only slight. Moreover, since 
all the original plats fared alike in the new treatment, the produc- 
tion records will first be considered without regard to the later salt- 
ing. Beginning in August, 1927, the field was heavily pastured. 
Since the last harvest from these palms was in June, 1928, the manure 
received through the pasturing presumably had no effect on recorded 
production. 
