174 
Gardeners and Florists’ Annual for J9J8 
Copper Sulphate (See Fungicides). 
Carnation Stem Rot, or Branch-rot. — This very prevalent 
trouble is caused by Rhizoctonia fungus. There are two forms of the 
disease, called dry stem rot or branch rot, and wet stem rot. The 
trouble was first reported in 1895. The disease attacks the plant just 
where the plant enters the ground. One branch dies, followed by 
others. Plants with good long stems above ground are less susceptible. 
Be careful not to plant too deeply, nor to bury the plant deeper than 
where it begins branching. Diseased plants, should be pulled up, and 
the ground around saturated with formaldehyde. The most critical 
Examples of Root-knot (See also under Eelioorms) 
Primrose roots badly 
infested with gallworra. 
Greenhouse soils kept 
at a mild, even tempera- 
ture furnish excellent 
conditions for the 
growth and rapid in- 
crease of this parasite. 
Chrysanthemum, the. 
roots of which are infested 
with gallworm. Plants 
severely attacked by this 
parasite are often dwarfed; 
they grow slowly and serve 
as breeding places for the 
nematode. 
From Farmers’ Bulletin 648, Dept. 
Carnation plant, the roots of 
which are much distorted and 
swollen as a result of gallworm 
infection. hlany greenhouse 
plants are similarly attacked 
when grown in soil which has 
not been sterilized. (All Draw- 
ings furnished by N. A. Cobb.) 
Agri. 
time in the plants’ history is usually when they are taken from the field 
to the benches. A high and moist temperature is very favorable to the 
disease. There is no absolute cure, but thoroughly healthy conditions 
and careful culture may and do prevent attack. 
Carnation and Chrysanthemum Root-knot. — Illustrations of 
root-knot are given in the calendarial section. The trouble is caused by 
a minute eelworm, this being called Heterodera radicicola. The presence 
of this nematode cause an irritation so that the tissues swell into knots, 
which interfere with the passage of water. The best remedy i.s to steri- 
lize the soil. An account appears in Farmers’ Bulletin 648. 
