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Posts and Thoin Control 
FOLIAR NEMATODE 
The spread of this pest has been very rapid in recent years owing to the increased trade in chrysan- 
themums, and the ease with which the nematode is transported in plants and cuttings. Too few 
growers have become familiar with this pest and consequently no effort has been put forth to control it. 
SYMPTOMS. The leaves attacked become blotched, turn at first greenish-yellow, then brownish, later 
gray and finally black until the entire leaf dies and hangs down on the stem. Under conditions 
of high humidity, both in the open during a wet season and under glass owing to excessive water- 
ing, the spread of the pest may be extremely rapid. 
CONTROL. P40 applied at the rate of 3 pounds per 100 square feet has given good control. 
Wait 2 to 4 weeks after benching before applying. It is better to apply P40 in 2 applications, 
I!/, pounds each time, 7 to 10 days apart. The latest findings show that foliar nematodes can 
be controlled with Parathion either as an aerosol or liquid spray. 
Diseases and Thoin Control 
BACTERIAL STEM ROT 
SYMPTOMS. Cuttings may appear healthy although infected, grow well up to 8-12 inches high when the 
stem becomes soft and off-colored. Pith is jelly-like or lacking in such stems. Tops of plants then 
turn black, exude drops of liquid, and the stem often splits. Develops at high temperatures (75-90°). 
Often shows up after the plants are pinched. 
CONTROL. Remove and burn immediately all affected plants. Wash hands thoroughly after handling 
plants. Steam infested soil before replanting. Avoid dips for cuttings. 
COLLAR ROT or STEM ROT 
SYMPTOMS. The area of stem just at the soil level will show dark colorings first. The entire stem 
will be girdled and eventually the plant will turn yellow and die. Usually caused by the common © 
damping off organisms such as Rhizoctonia, Fusarium or Pythium. More prevalent when tempera- 
ture and humidity are high. 
CONTROL. Do not plant cuttings that have been affected with damping off. Remove all affected 
plants when noticed. Do not keep the soil too moist. Run a lower humidity if possible. Plant cut- 
tings no deeper than depth they were in propagating media as too deep planting will hasten de- 
velopment. Have soil well prepared as compact soils will also encourage trouble. 
MILDEW 
SYMPTOMS. Whitish powdery growth on upper surface of leaves. 
CONTROL. Spray at regular weekly intervals with a good Wettable Sulfur, 1!/> lbs. per 100 gallons of 
water to which a good commercial spreader has been added. Spray with Iscothan 6 ozs. per 100 
gallons of water plus spreader whenever disease appears. 
Eelworms moving from Eelworms entering leaf Eelworms feeding and breeding in leaves Eelworms overwintering in 
the ground up the out- through the stomata. and migrating upwards from leaf to leaf. soil, dead leaves and 
side of the stem and (Spring-Summer) (Spring-Autumn) in basal buds. (Winter) 
leaf-stalks into the (Spring-Summer) (Sprimg-Ayfumn) in basal buds. 
basal leaves. (Spring) (Winter) 
