14 
BULLETIN 72, HAWAII EXPERIMENT STATION 
and for that reason the results on the air-dry basis indicate that Mer- 
ker slightly outyielded Napier grass. The air-dry weight is much the 
more accurate basis for the comparison of yields of forage crops, as 
the moisture content varies considerably in different varieties and 
within the same variety at different growth stages. The differences 
between the yields of the Napier and Merker strains, which range 
from 1.5 to 1.8 tons per acre per year, are too small to be of any 
practical significance. These data indicate then, as did those in table 
1, that Merker and Napier grasses do not differ significantly in the 
production of dry matter during the first year of their growth. They 
suggest, however, that Napier grass may be more palatable than 
Merker grass because of its greater succulence and its higher moisture 
content. They show little difference in yield of air-dry forage between 
the two strains of Merker grass included in the test. 
YIELDS IN OTHER REGIONS 
Langer (6, p. 63), in reporting on Napier-grass trials in Paraguay, 
states that 3 to 6 ratoons will yield from 60,000 to 120,000 kilograms 
per hectare, which would be about 26.7 to 53.5 tons per acre. Reports 
from the Guam Agricultural Experiment Station (3, p. 9) give an aver- 
age of 15,848 pounds per cutting per acre of green forage for Napier 
grass and 13,477 pounds for Merker grass. Napier grass has yielded a 
higher tonnage of green fodder than Merker grass during a period of 5 
years. On the dry basis, however, there would probably be little 
difference between the two varieties. 
CHEMICAL COMPOSITION 
The chemical composition of a grass determines, to some extent, its 
feeding value. Inherent differences in composition, particularly in 
regard to the protein and ash constituents, are of importance. The 
greatest single factor in determining the chemical composition of a 
forage crop is probably the stage at which the plants are cut. Pasture 
grasses cut at a very immature stage, when most of the forage con- 
sists of leaves and tender stems, are high in protein and total ash, 
approaching or surpassing that found in high-protein dried roughages 
such as alfalfa. In the choice of a forage crop then, it is important 
to know if the crop can be cut at a stage when it contains a high 
percentage of protein and a low percentage of fiber. High yields can 
be obtained with Napier grass cut at a relatively immature stage, 
when it is very palatable and nutritious. Chemical analyses were 
made of samples of Napier, Merker, guinea, and Sudan grasses col- 
lected at different times during the year from the university farm 
plats and representing the actual condition of the grasses when they 
were harvested for dairy cattle feeding. The results are shown in 
table 4. 
Table 4. — Corn-position of fodder grasses 
Average 
period 
between 
cuttings 
Analyses 
Composition on basis 
weight 
of oven-dry 
Grass 
Crude 
protein 
Fiber 
Total ash 
Days 
63 
54 
48 
62 
Number 
13 
13 
7 
9 
Percent 
6.84 
7.17 
6.02 
4.96 
Percent 
33.78 
34.46 
33.66 
33.10 
Percent 
17.48 
16.30 
11.50 
16.50 
