108 REPORT OF THE DEPARTMENT OF BOTANY OF THE 
in diseased carnation buds is the following: The mite visits healthy 
carnation buds for the purpose of feeding on the tissue of the 
floral organs. Spores of the fungus carried on or in the body of 
the mite germinate and produce a mycelium which attacks the in- 
terior portions of the bud and causes them to decay. In this de- 
caying tissue the mite finds a congenial breeding place. When the 
young mites are able to travel they migrate to healthy buds carry- 
ing with them the spores of the fungus. 
The above applies especially to carnations. Probably, it applies 
also to June grass, but the association of mite and fungus on June 
grass seems to be much less constant. 
CONTROL OF CARNATION BUD-ROT*4 
Probably, bud-rot will rarely be sufficiently destructive to require 
special methods for its control. If this be true it is fortunate, 
because there is, as yet, no line of treatment which can be confi- 
dently recommended. The Station has made no experiments along 
this line. 
Certainly, all diseased buds should be carefully gathered and 
burned, because they contain countless numbers of fungus spores 
and mites by means of which the disease is spread. 
Another possible line of treatment is the elimination of suscep- 
tible varieties. Although several varieties are more or less subject 
to bud-rot it is destructive to only a few varieties chief among 
which are Lawson, Enchantress and Bradt. 
The fact that bud-rot is a fungus disease suggests that the carna- 
tions should be kept as dry and cool as is compatible with good 
growth, because it is well known that abundant moisture and high 
temperature favor the growth of fungi. However, in this case, 
another factor, the mite, must be taken into consideration. There 
is good reason to believe that the mite is an important factor in 
spreading the disease. While nothing is known as to the effect 
of moisture on this particular mite it is known that mites in gen- 
eral thrive best under dry conditions. 
The fact that the mite associated with bud-rot is one which feeds 
on various grasses, particularly June grass, suggests that the plant- 
ing of carnations near grass land or the use of sod in the prepara- 
tion of greenhouse soil may encourage bud-rot. Excepting the ob- 
servations made by Mr. Davis in Illinois (p. 144) we have no 
“By F. C. Stewart and H. E, Hodgkiss. 
