24 MISSOURI BOTANICAL GARDEN BULLETIN 
lowed as closely as possible would result in greater satisfac- 
tion among the flower-buying public. 
Both the herbaceous and tree peonies are readily forced 
in the greenhouses. The plants should be lifted in Septem- 
ber after completion of their growth, potted in rich soil, and 
plunged into a cold-frame, where they should remain until 
about December. When first placed in the greenhouses a 
temperature of 40-45° F. should be maintained, gradually 
being raised to 55-60° F. Under such treatment, with fre- 
quent applications of liquid manure, the tree peonies may 
be forced in six weeks and the herbaceous kinds in about 
eight to ten weeks. Double-flowering varieties should be 
used for forcing, their flowers possessing longer keeping 
Y Negare After forcing at least two years should elapse be- 
ore the same plants are forced again. 
Comparatively, the peony is immune to insect attacks and 
in a lesser degree the same holds true for fungous diseases. 
By far the most important disease is the Botrytis blight, oc- 
curring simultaneously in widely separated localities, espe- 
cially during a wet spring. It is caused by Botrytis paeonzae 
—a fungus belonging to a widely distributed genus attack- 
ing many ornamental and economic plants. The disease 
affects the stems, buds, and leaves. In the early spring an 
attack upon the stems often results in rotting and complete 
wilting. The buds are the next to succumb to the attack, 
indicated by wilting, drying up, or failure to open. In wet 
seasons as many as 90 per cent have been found blasted in 
this fashion. The leaves show symptoms of this disease in 
the form of blotches spreading from the apex, which soon 
become brown and dry. In all cases a thick felty covering 
of spores indicates the presence of the parasitic organism. 
Due to the wide-spread nature of the disease, numerous 
hosts, and transference of spores by ants, methods of con- 
trol are not efficacious. Spraying is not desirable because 
of the discoloration of the buds and foliage and the neutral- 
ization of copper in the Bordeaux mixture by the exuded 
sugary solution from the buds. Sanitary eradication meas- 
ures promise a greater degree of success. Cutting away and 
burning the old stubble in the fall and replacing the old 
soil at the top by fresh sand, as well as removal of all in- 
fected stems in the spring, will reduce the chances of infec- 
tion of the buds. Rotted buds full of spores should be re- 
moved and burned. 
A number of other diseases have been observed, but in 
most cases they are not very serious and no effective meas- 
