rae 
WEST CHICAGO 
ILLINOIS 
Common Mum diseases: left to right, normal leaf, septoria feat spot, foliar nematode, puccinia (rust), botrytis (petal rot), and ascochyta 
petal blight). 
5. Petal rot (ray blight or botrytis): a serious problem 
especially on standards flowered under hot or humid condi- 
tions. A very effective preventive spray: per 10 gallons of 
water, | 2 oz. Parzate, and spreader. Apply every 4 to 7 
days as needed, starting as color shows. 
Use maximum pressure (200 Ibs. or more) just hit flower 
buds and blooms. Takes only 4-5 minutes per 150 ft. bed. 
6. Over a period of years, we find that insects (aphis es- 
pecially) tend to become resistant to any one insecticide. 
Therefore, we change occasionally—using such materials as 
Lindane, nicofume pressure fumigators (under sateen), Ara- 
mite spray, Vapotone. 
#9. MUM DISEASES 
For simplicity, the preventive sprays for control 
of septoria leaf spot, mildew, petai rots, etc. were 
included under the insect section (page 5). 
Here’s a brief run-over on mum diseases: 
Petal Rot (see photo) 
These rots can ruin an otherwise fine crop—and 
in a hurry, too! Suggestions: 
a. Under glass: fairly heavy shade, especially 
on standards flowered in midsummer, will pre- 
vent sunburn injury. Ample ventilation, even a 
little heat on during summer evenings helps 
prevent botrytis—keeps petals dry. Also, of 
course, Parzate spray on flowers from the time 
they show color. (Note 5, above.) 
b. Outdoors: spray programs (page 6) are 
very effective. Parzate as a dust kept on open- 
ing flowers has given even better control for 
growers on the Gulf coast. 
Septoria leaf spot (see photo) 
Worse on outdoor crops. Clean cuttings plus the 
preventive spray program on page 6 will give good 
control. 
Verticillium 
Clean (cultured) cuttings planted to sterilized 
soil will eliminate it. Our cuttings are cultured! 
Stunt 
A virus that will stunt occasional plants to 1/2 or 
24 normal height—and bleach flowers of red and 
bronze varieties. Again, clean cuttings on steril- 
ized soil ordinarily eliminates this problem. 
Foliar Nematode 
Tiny worms feeding within the leaf tissues cause 
this condition. Especially under outdoor—or any 
warm, wet conditions, it can spread very rapidly. 
Control: preventive spray program, page 6. The 
Parathion does it. 
Dodder 
Pale, yellowish to orange threads (vines) grow- 
ing very rapidly over stems, leaves and flowers— 
that’s Dodder. It has no leaves—being a parasite. 
It can ruin a bed of mums in 2 weeks. Usually it 
comes in with peats, soils, or manures from out- 
doors. Steam kills it. 
Once a bench is affected, it is far cheaper to 
remove and burn all affected plants. 
#10. CLOTH HOUSE ANGLES 
Top quality pomps are flowered under cloth 
from August | into October—if frost protection is 
available. Pointers. 
a. Schedules—the regular tables apply. 
b. Diseases are something more of a problem 
than under glass. The preventive sprays outlined 
on page 5 will keep them clean ordinarily, 
though. 
a Bd Pol % oe 
September Standards grown under plastic protection. At least in our 
section, it is necessary to protect outdoor grown Standards from rain 
or they will rot ruinously. These glass substitute roof sash, if properly 
installed, will do a fair job. But they are not as tight as glass, are 
subject to storm and wind damage—aond if considered over a period 
of years are not really cheap. Perhaps as we gain more experience 
with these plastics, and as the materials themselves improve (they 
are!), they may come into more general use—especially in the near 
South where winters are mild. 
7 
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