DISEASES 
We have noticed considerable plant loss the past few years in our visits 
to many greenhouses, this Icss has been caused in the most part by 
Verticillum Wilt, also Rizoctonia Stem Rot has brought about hizh losses 
in other ranges. To control these diseases we advise you to follow the 
recommendations printed in circular No. 423 “Diseases of Commercial 
Florist Crops” printed by the Penna State University, College of Agri- 
culture, Agriculture Extension Service, State College, Pa. Their recom- 
mendation follows below. 
Control of Wilts: Treat seed with Semesan dust, take on the end of a 
toothpick or knife blade, Semesan dust equal in volume to a Tomato seed, 
place dust in seed packet and shake thoroughly so that the seeds are 
coated evenly with the dust. Plant seed in sterilized soil or vermiculite. 
Transfer seedlings to sterilized soil, taking care to prevent recontamina- 
tion. Pots, benches and flats when NOT sterilized may be sources of 
contamination with the wilt organisims. 
We suggest that this seed treatment be used on a trial 
basis only, as Semesan will retard germination. 
POWDERY MILDEW 
The leaves and often the stems become covered with white mold-like 
growth. CONTROL: Avoid excessive humidity, keep from splashing water 
on the foliage and allow plenty of ventilation. Spray with Mildex, 4 ozs. 
per 100 gals, and repeat in 5 to 7 days, apply when temperature is below 
90° F. and when foliage is dry. More than two sprays may cause injury. 
We have also observed good results from the use of a spray consisting 
of % oz. Baking Soda to 1 gal. water. Mildew may be prevented by dust- 
ing with Sulphur or spraying at 7-10 day intervals with wettable Culphur, 
2 Ibs. per 100 gals. DO NOT APPLY SULPHUR AFTER THE FLOWER 
BUDS START TO OPEN. 
DOWNY MILDEW 
The undersides of the leaves and the stems become covered with patches 
of purplish-white mold-like growth. Keep foliage dry and humidity low, 
destroy all infected plants. Spray with Zineb (Parzate or Dithane 2-78) 
1 Ib. to 100 gals. at 5-10 day intervals. 
RUST 
Rust fungus appears as reddish-brown powdery pustules on leaves, 
stems and seed pods. Rust spores are spread by air currents or careless 
watering. Where rust has been prevelant, follow a good spray program 
and start when plants are 4” high. 
CONTROL: Grow plants from seed only. Use Parzate, 2 lbs. per 100 gals. 
