Be 
INSECT AND FUNGUS PROBLEMS 
LIKELY TO BE ENCOUNTERED IN 
GROWING OUTSIDE MUMS, AND 
A PRACTICAL METHOD OF CON- 
TROLLING SAME. 
While the chrysanthemum when grown commercially 
under glass is usually given a complete spray program, 
the small—and often amateur, grower of mums in yard 
or garden finds it difficult to “figure out” a small, in- 
expensive spray rig and spray program that will insure 
perfect blooms in the fall. 
Until recently it has been possible to grow fine mums 
in the open yard or garden with little trouble from insect 
enemies or fungus diseases ,and as a result mots small 
growers did little spraying. 
However, it now appears that the Thrip and Septoria— 
the fungus disease that causes dead leaves and often 
referred to as “Leaf-Spot,” will play an increasingly 
large part in the game of growing mums outside in the 
Southern States. Unless one sprays for these two enemies 
{one insect and one fungus) the results in the fall will 
be mediocre at best, and if the summer has been wet and 
the fall unusually warm, then the result will be a com- 
plete failure. The stalks will have dead leaves almost 
all the way up to the top, and the bloom will be only 
partly open and appear to be “blighted.” 
This condition seems to be wide-spread throughout the 
country, and from the many letters I receive, it appears 
that most people do not know the real cause for “dead 
leaves” and “blighted” blooms. It is with a view of help- 
ing this situation that I am sending this little leaflet 
along with my mum catalogue. 
The Thrip is a very small insect about the size of No. 
100 silk thread (and that is very small), and about 1/16th 
of an inch long. At first they attacked he Gladiolus, -but 
in the past few years have taken to the mum as well. 
They do not cause too much damage to the foliage along 
during the summer, but when the buds form they move 
up to the top of the plant, and when the petals start to 
unfold in late summer or fall they enter the partially 
open bud. In between the petals they are safe and from 
this vantage point they feed on the juice of the petals— 
inserting their bill into the petal near the base and 
sucking the juice out. Examination of a half-opened bloom 
that has Thrip will usually show the yellowish-brown 
stains near the base of the petals, where the Thrip has 
punctured the petal and sucked the juice. Petals thus 
attacked cease to grow, turn brown at the tips, then turn 
black and finally rot sets in. Many people think this is 
due to a “blight” or “rot”? whereas the tiny Thrip is the 
real cause of it. While difficult to see, owing to their 
small size, if one will tear an infected bloom to pieces 
over a sheet of white paper, then remove the petals from 
the paper, a number of Thrip will usually be seen moving 
about on the paper. The very young will be a clear 
yellow, the half-grown ones brown, and the mature ones 
almost black. They move in quick bursts ofspeed, and 
often appear to jump (actually they fly but it is almost 
impossible to see their wings). This habit has earned for 
them the nickname “Flips” in many greenhouses. 
The Septoria or Leaf-Spot is a fungus disease and can 
not be seen, but its presence can be detected by the | 
