32 BULLETIN 52, HAWAII EXPERIMENT STATION. 
be given here, but the condition of the plants in the check rows 
showed that ' 'manganese yellows" can not be overcome by use of the 
ordinary fertilizers. 
This field was given three sprayings with the experimental sprayer 
previously described. Some parts of this field were not sprayed 
until June. So severe were the effects of the manganese that a great 
number of plants appeared to be destroyed, but a vigorous growth 
of green suckers as a result of the spraying produced a good ratoon 
crop. 
Fart of the field on which this experiment was made was sprayed 
three times in April. Previous to this the plants had been gone over 
four times with a hand sprinkler containing a solution of iron sul- 
phate (10 pounds to 50 gallons). Two 300-foot rows were left un- 
sprayed as checks, and two others received only a single spraying 
with the experimental sprayer. The two rows adjoining the un- 
sprayed rows were held for comparison with them, as in these long 
rows the effect of any possible variations in the soil is eliminated. 
Samples of the soil were taken at various places between the two un- 
sprayed rows and likewise between the two sprayed rows. The 
analyses of these soils, given in Table 2 as Nos. 637 and 638, show 
5.19 and 5.12 per cent, respectively, of manganese as Mn 3 4 . A 
comparison of these analyses of the soils under the unsprayed and 
sprayed rows, respectively, shows that any difference between 
them is to be ascribed to the spraying treatment. 
The effect of spraying on the stunted red fruit was even more 
remarkable than that on the yellow plants. These characteristic 
fruits of manganiferous soils became normal dark green and com- 
menced a most vigorous growth within two or three weeks after they 
were sprayed. A decided change in them could be noticed within a 
week. If some of the iron solution struck one side only of an unripe 
fruit this side became green first and made such growth that the fruit 
soon presented a ''lopsided" appearance. Later the iron appeared 
to be evenly distributed, because the fruit was fairly symmetrical 
when ripe. 
Plate III, Figure 1, shows the appearance of the unsprayed and 
sprayed rows on May 19, 1916, about a month after the spraying was 
done. The view is taken looking north along the rows. The un- 
sprayed row on the left was closest to the camera, but the great im- 
provement in size and appearance of the fruit on the two sprayed 
rows to the right is evident. It is impossible to show with an ordi- 
nary photograph the great difference in color which made the yellow 
check rows in the green sprayed field visible at a long distance. 
The rows which received one spraying were quite yellow, but had a 
greenish tinge compared with the unsprayed rows. 
Plate III, Figure 2, shows a view taken halfway along the rows look- 
ing south. The unsprayed rows on the right illustrate the variable 
destructive effects of the manganese soils on the pineapple plant. 
The two plants in the right foreground set small red fruit which 
cracked open around the eves and decayed. Some of the red fruit 
reaches maturity without clecay, but it is of very inferior quality. 
The third plant visible in the unsprayed row did not blossom at all 
and was slowly dying when photographed. The plants immediately 
beyond this suffered the most serious injury, the few dying yellow 
leaves which were left turning brown and shriveling at the time the 
