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Year-Around Flowering of Chrysanthemums 
Shading 
Use a good durable Black Cloth which when applied 
will reduce the light intensity to 2-foot candles or less. 
More light intensity than this will result in delayed 
flowering and unevenness of bloom. 
The cloth should be applied at 5 p.m. and removed 
at 8 a.m. Continue covering each evening on pompons 
until the latest buds show color and most of the flowers 
are well developed. For large flowering varieties, 
shading can be discontinued after all flowering buds 
have attained the diameter of approximately one- 
half inch. 
Be sure that covering is complete on all benches 
shaded, as any leaks in light will cause uneven spots 
in the bench at blooming time. 
Black cloth should be applied each evening. Missing 
one night a week will give fair results, but delayed 
flowering results when cloth is not applied each evening. 
Temperature Control 
For bud formation, a minimum temperature of 60-65 
degrees should be maintained. During the growing 
period, a night temperature near 60 degrees is ideal. 
When black cloth treatment is started, raise the night 
temperature to 60 degrees until color shows and then 
drop to 52 to 55 degrees. Excessive high temperatures 
prohibit the bud development, and during seasons of 
night temperatures above 90 degrees, it is suggested 
that the black cloth be raised after sunset and lowered 
again in the morning before daylight. This cooler tem- 
perature hastens the development of the buds. 
Temperature regulation becomes a problem to the 
grower who is growing a single bench of chrysan- 
themums in a cool house. A simple method is to apply 
black cloth, allowing the cloth to drop to the ffoor on 
each side of the bench and then turn on the heat lines 
under the bench. This will trap the heat under the cloth 
and raise the temperature sufficiently to set buds. 
interrupted Lighting 
You get quality when you control the spray formation 
in pompons. The control is easy and consists of inter- 
rupting the lighting: It will give you no more work but 
does take a little more planning. The control gives you 
a spray with a more open head; the spray is more 
uniform; the flowers are larger, and the color is more 
intense. 
In timing a crop which is to receive an interrupted- 
lighting treatment, we must start the short-day treat- 
ment earlier than normally, advancing the date by the 
number of long days which will be used to interrupt 
the short-day period. For example, if the short-day 
treatment were to start on January 15 and continue 
to flowering. The interrupted-lighting treatment is set 
up for 10 short days followed by 10 long days. Short 
days would be given the plants from January 5 to 
15, followed by 10 long days until January 25 and then 
short days to flowering. Remember that the total num- 
ber of long days is the same as given in the schedule. 
Use of Interrupted Lighting Only on 8, 
9, and 10-Week Response Varieties 
Week response Number of short days followed by 10 long days 
8 week 9 short days 
9 week 10 short days 
10 week 11 short days 
An interrupted-lighting treatment of 10 short days, 
10 long days, then short days to flowering has made 
it possible to improve the quality of pompons by im- 
proving the spray formation; now this same treatment 
can be used on certain standard varieties where qual- 
ity is poor because of open centers. Best to try inter- 
rupted lighting on a limited scale until you know how 
to handle this treatment. 
Much research on interrupted lighting is now being 
done to find the exact number of short days and long 
days for each response group. We feel that this 
information is very valuable for growers who are 
flowering 8, 9 and 10-week varieties during January, 
February and March in Florida. 
