27 
later development of the disease is shown by the following observation 
of Mr. Du Bon: “It happened once that in a portion of a field every 
other plant was a calico plant and the alternating ones were healthy 
plants. This remarkable circumstance found its explanation in the fact 
that in the process of machine planting two baskets were used contain- 
ing the plants of two different seed beds, one bed being in a condition 
to favor the disease, the other containing new soil. Two planters 
worked here at the same time. The neglect of proper precaution in 
taking the young plants from the seed bed may create a tendency to the 
disease.” In this connection Mr. Barnes, of Hatfield, Mass., related 
the following: ‘Young plants were taken from the same seed bed by 
two different farmers, and, although the soil of the fields was the same, 
one farmer had many calico plants in his field and the other had almost 
none. Inquiry revealed the fact that one farmer took the plants from 
the seed bed when it was quite dry, the other when it was well 
moistened. In taking the plants from a dry bed one can not help lacer- 
ating the roots, while from a well-moistened bed the roots may be 
withdrawn in an almost intact condition. Lacerated roots do not 
generally develop again to such a vigorous state as is required by the 
quickly growing tobacco plants.” 
For the prevention or diminution of the disease, Mr. Du Bon recom- 
mends keeping the plants in the seed bed not too warm and also chang- 
ing the seed bed. Beds that produce the disease might be grown over 
for one year with grass, in order to put them in proper condition for 
the production of healthy tobacco plants. While many planters seem 
convinced that the diseased plants can not recover, others claim that 
by hoeing and stirring the soil well the disease may be cured in the 
initial stage. Mr. Barnes, of Hatfield, Mass., claims to cure the disease 
by lifting the whole plant a little from the ground. In both cases a 
better aeration of the soi] is reached. The writer is not prepared to 
confirm or contradict these statements. 
OBSERVATIONS ON CURING.! 
INTRODUCTION. 
The curing period is a time of continuous anxiety for the tobacco 
planter. Too dry weather stops all changes in the leaves, particularly 
the development of the proper color, while too moist weather, especially 
at a temperature above 24° ©. (75° F.), favors the disastrous pole 
burn. The great desire of the tobacco planter to become entirely inde- 
pendent of the weather by such improvements in the barn construction 
as will permit the proper regulation of the temperature and moisture is 
therefore reasonable. 
The general introduction of an ideal tobacco barn can be only a ques- 
tion of time. If the tobacco is becoming too dry, steam should be 
turned into the building; and if it is becoming too moist, dry heat 
1These observations were made with leaf cured on the stalk. 
. 
