26 
seed tobacco was in excellent condition, had applied per acre the 
following amounts of fertilizers in the drill: 
5 cart loads horse manure, 
20 hundredweight of cotton-seed meal, 
500 pounds of “ dissolved bone black,” 
500 pounds cotton-hull ashes, and every other year 
300 pounds of lime. 
On a field near East Hartford, Conn., many more calico plants were 
to be seen than on another field on the opposite side of the road—on 
the former about 8 to 10 per cent, on the latter only about 3 to 4 per 
cent. This difference might be ascribed to differently manured seed 
beds or to the different manuring in the field. Both farmers applied 
horse manure—the first. 5 cart loads to the acre; the second, 9 cart 
loads to the acre. The former also used 10 hundredweight of bone dust, 
while the latter applied 800 pounds per acre of the following mixture: 
150 pounds of ammonium sulphate, 
450 pounds of potassium sulphate, 
640 pounds pulverized bone and meat, 
600 pounds of ‘‘ dissolved bone black.” 
The latter had therefore applied not only much more horse manure to 
his field, but also more of the easily accessible phosphoric acid and 
more potash than the former.’ : 
Mr. Du Bon, a good observer, reported to the writer the following: 
The calico disease may appear even in the seed bed, especially when it is too rich 
in nitrogenous manure, but the first two or three leaves of the attacked plants are 
generally normal. Fresh soil that has never served for raising crops does not pro- 
duce the disease in the seed bed nor does an excess of moisture, but too high tem- 
perature is likely to produce it. Yellow plants, stunted in the seed bed by cold 
weather, never show mosaic disease in the field. In one case it was observed that 
an acre and a half planted with such yellow plants did not show a single calico 
plant, while the neighboring acres, planted with vigorous seedlings, developed a 
great many. Very vigorous plants that had been manured heavily with castor 
pomace and were looking very well showed much calico later on. 
The disease is not easily propagated through the soil of the field: 
Even twin plants may be found where one is much attacked and the 
other bears hardly a trace of the disease.” Near Poquonock fields have 
been used for twenty-five years uninterruptedly for the culture of 
tobacco, and upon this land thoroughly healthy crops are now produced, 
although formerly the disease was often observed. One year, on a 
piece of land that contained 12,000 plants, 3,200 calico plants were cut 
out with a hoe when the plants had reached about 2 feet in height. 
The following year hardly half a dozen calico plants were noticed on 
that same plot, but these plants came from a seed bed containing 
new soil. The great influence of the growth in the seed bed on the 
‘Koning (Zeitschrift fiir Planzenkrankheiten, 1899, p. 65) asserts that manuring 
with kainit and Thomas phosphate diminishes the extent of the disease. 
>This fact seems to be in contradiction to the behavior of the plants in the seed 
beds. A satisfactory explanation is wanting. 
