196 
FLORIDA STATE HORTICULTURAL SOCIETY 
Senator Darby used sulphur solution in 
the form of Sulpho-Citrol on his citrus 
trees to a very good advantage by keeping 
his fruit bright. 
Question 24. Can you give us any 
information as to whether the waste or 
slag from the acetylene gas plant can be 
used on plants, vegetables or fruit trees, 
and also just what effect it will have on 
the soil? 
Mr. Jack Peters spoke of the great im¬ 
provement of the appearance of the grass 
along the drainage way where this slag 
was carried off. 
Capt. Rose stated that as acetylene gas 
slag was carbonate of lime, it would be 
a good corrective of soil acidity. It would 
prove beneficial in the same way that 
ground lime stone proved advantageous. 
Question 25. Have any experiments 
been made (and with what results) in the 
use of finely ground phosphate rock as 
a citrus grove fertilizer? 
Capt. R. E. Rose, State Chemist, re¬ 
plied that finely ground soft phosphate 
rock was approximately as available to 
the citrus trees as was Thomas {slag, 
and while it was not being used very 
largely, it would probably come into gen¬ 
eral favor. 
Question 26. Will the whitefly fun¬ 
gus applied during a continued dry per¬ 
iod, live and be effective, although not 
spreading? We know it does not spread 
in dry weather. 
There are said to be two kinds of fungi 
which will eradicate the whitefly. Is this 
so? If so, what are they and which is 
the better ? What is the difference ? 
Do you consider a spray more effective 
to destroy the whitefly than a fungus, and 
if so, what kind of spray and when is the 
proper time? 
To all these questions, Mr. Hume rec¬ 
ommended the inquirers to obtain and 
read carefully Florida Experiment Sta¬ 
tion Bulletin No. 103. 
Question 27. Will sweet potatoes do 
better on a soil more sandy than a low, 
heavy soil? 
Mr. Jack Peters stated that he pre¬ 
ferred to use the high, rolling pine land, 
but that there was a difference whether 
you are growing sweet potatoes for mar¬ 
ket or were growing sweet potatoes for 
home use. A lower and heavier land 
would be liable to give a higher yield, but 
not as good a quality as the higher land. 
Dr. Stockbridge stated that the heavier 
lands would produce a much larger crop 
than the lighter soils. 
Ouestion 28. Will barnvard fertilizer 
J 
make scabby potatoes? If so, what will 
prevent it? 
Mr. Hume replied that scabby potatoes 
resulted from the presence of scab-pro¬ 
ducing fungus, which was usually carried 
to the field by the seed tubers. This fun¬ 
gus does not occur readily in acid soil, 
but will grow readily in neutral or alka¬ 
line soils. The germs are likely to be 
-present in many of the barnyard manures. 
There are, therefore, two lines of preven- 
tatives; dipping the seed potatoes in for¬ 
maldehyde or corrosive sublimate solution 
and thus keeping from spreading the dis¬ 
ease on the field, or another way is to 
keep the soil acid. 
Question 29. Why does the Florida 
grower pay more for fertilizer materials. 
