FLORIDA STATE HORTICULTURAL SOCIETY 
63 
wards injuring the host tissues, but are, 
from their very solubility more easily 
weathered away than the less soluble, and 
probably slower acting materials. Spread¬ 
ing power as well as sticking power is a 
desirable quality in the ideal solution. 
All sorts of fungicides, good, bad and 
indifferent, have been devised and recom¬ 
mended for controlling crop diseases. A 
word of caution must be given against the 
large-scale use of proprietary prepara¬ 
tions made merely to sell, before their 
worth has been demonstrated in small 
tests carefully made and checked. 
We will confine our attention to three 
standard mixtures that are in rather gen¬ 
eral use for citrus diseases. Bordeaux 
mixture, ammoniacal copper carbonate 
solution, and lime-sulphur solution. 
Bordeaux mixture has good fungicidal 
value, perhaps more lasting than imme¬ 
diate. It sticks well; the sediment may 
be objectionable on fruit nearing ma¬ 
turity. There is a certain amount of 
deepening of leaf color and apparently 
stimulation of the host plant following 
its use. Its use may be followed by an 
increase of scale insects in the grove, 
and close watch must be kept, and timely 
measures taken for their control when 
necessary. To many this effect is a de¬ 
terrent against any extensive use of 
Bordeaux mixture. Others find it pos¬ 
sible to take advantage of its good quali¬ 
ties by assigning it a proper place along 
with other sprays in a year-round sched¬ 
ule. 
Ammoniacal copper carbonate has fair 
fungicidal power, but is not very lasting. 
There is practically no sediment to mar 
the appearance of ripening fruit, and it 
has little tendency to produce increase of 
scale insects. It may act on the metal of 
spray machinery, causing it to wear out, 
probably the consequence of improper 
mixing of the spray. 
Lime sulphur solution does not have a 
very long record in the control of citrus 
diseases on which to base conclusions. It 
has good fungicidal power, more im¬ 
mediate than lasting. It leaves a slight 
sediment. It tends to reduce certain in¬ 
sect pests, thus combining insecticidal and 
fungicidal properties. It consists of 
rather unstable chemical compounds, and 
there is the possibility of transformations 
occurring under certain atmospheric con¬ 
ditions that may give rise to spray injury. 
Temperatures above 85 degrees immedi¬ 
ately after spraying seem to be unfavor¬ 
able for its use on citrus at strengths 
effective against parasitic fungi. Late 
afternoon spraying in warm months may 
escape this danger. 
Each one of these solutions must be 
prepared accurately. Carelessness in 
mixing or diluting may make the dif¬ 
ference between success and failure. 
Give attention to purity of ingredients, 
standards of strengths, right methods of 
mixing and conveniences in mixing. 
No one of these solutions meets all the 
requirements of the ideal, universal spray 
material. Some day such may be pro¬ 
duced ; until then we must use what we 
have to best advantage. A combination 
schedule, in which more than one spray 
finds a place, may offset the disadvan¬ 
tages of any spray used alone. Care 
must be taken to avoid the injury that 
may be caused by the mixing of different 
sprays, as the copper and sulphur ones on 
