PAGE 12 
(Continuous Flowering of Chrysanthemums 
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 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 de- 
grees it is suggested that the black cloth be raised after sunset and lowered again in the morning 
before daylight. This cooler temperature hastens the development of the buds. 
When growing a single bench of pompons in a cool house, it has been a problem how to increase 
the temperature necessary for bud set. A simple method is when applying black cloth allow the cloth 
to drop to the floor on each side of the bench. Turn on the heat lines under that bench and you will 
find that a 60 to 65 degree temperature can be maintained. 
Interrupted Shading to Control Pompon Sprays 
Quality can be obtained when you control the spray formation in pompons. The control requires no 
more work than normal but does require a little more planning. The result of controlling the spray is 
a more open head, uniformity, and larger flowers. The color is more intense with most colored varieties. 
Two general types of controlled sprays are most useful. 1. Terminal bud set, followed by a period of 
long days to allow the buds to develop greater size and the individual little flower stems to elongate. 
The schedule for producing this allows 21 to 28 long days from the pinch to the first short day treat- 
ment, 12 short days, 10 long days, then short days to bloom. This schedule requires about 7 days 
longer for development than if the original short day treatment were continued to flowering. The 
sprays appear to have been disbudded because the original bud set develops on long stems. It is 
probably the most desirable of the two types of controlled sprays now recommended for most mar- 
kets. 2. Branched sprays are produced by giving 4 short days, followed by 15 to 20 long days, then 
short days to bloom. The first short days produce a crown bud which causes lateral shoots to de- 
velop below it. If 15 long days follow the short day treatment, the laterals will have stems 8 to 15 inches 
long. They form terminal clusters. If you are going to disbud or if your trade likes branched sprays, this 
is the way to get them uniform. 
interrupted Lighting 
This is very similar to interrupted shading onl applied to the continuous flowering schedule. After the 
plants received their normal lighting period ihe plants are given 12 short days followed by 10 long 
days and then short days until flowering. In timing a crop which is to receive an interrupted light- 
ing treatment, we must start the short day treatment 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 12 short days followed by 10 long days. Short days would be given the 
plants from January 3 to 15 followed by 10 long days until January 25 and then short days to flower- 
ing. Remember that the total number of long days is the same as given in the schedule. 
An interrupted lighting treatment of 12 short days, 10 long days, then short days to flowering hds made 
it possible to improve the quality of pompons by improving the spray formation; now this same treat- 
ment can be used on certain standard varieties where quality is poor because of open centers. Best 
to try either interrupted shading or interrupted lighting on a limited scale until you know how to 
cle this treatment. 
Extensive research on interrupted lighting is now in process to determine the exact number of short 
days and long days for a response group. We feel that this information is very valuable for those 
who use the continuous flowering schedule. Our representatives will be informed on the outcome and will 
discuss it with you. 
