Cultural Pointers 
FERTILIZERS 
Soil structure is the key to soil fertility. The response 
of chrysanthemums to fertilization depends upon a 
favorable soil structure. It is known that plants require 
nutrients, water and air for growth. Good soil structure 
will provide proper air and water relationships. There- 
fore, it behooves us to give proper attention to the 
soil before starting the crop. Good open soil is a 
necessity. 
Feeding 
Chrysanthemums do much better right from the start 
if the soil is not too rich, Very often this crop will start 
off faster in new soil as compared to old soil that has 
been sterilized just because of the lower nutrient level 
in new soil. When using new soil, apply 5 pounds of 
superphosphate per 100 sq. ft. of area, plus a liberal 
application of manure before planting. Phosphorus 
moves slowly within the soil mixture. It should always 
be added before the crop is benched so that it may be 
mixed thoroughly into the soil. One to two pleas 
tions of a complete fertilizer, such as Electra, made 
after the plants become established and until color 
shows will be adequate. Electra applied at the rate of 
2 pounds per 100 sq. ft. of bed is sufficient. Never 
apply fertilizers to a dry soil. Water lightly first, then 
apply the proper quantity of fertilizer, and then water 
heavily. Liquid feeding with water-soluble fertilizers is 
fast becoming the popular method of applying fertilizer. 
Remember that the plant is the best guide to fertilizer 
requirements and that more mums are ruined by over- 
feeding than by nutrient deficiencies. 
Levels of Nutrition 
When using sterilized soil, the best recommendations 
to follow would be to analyze your soil from time to 
time. We have found that when the following nutrient 
levels are kept, good crops are the result. Nitrate 
nitrogen should be 5-10 p.p.m.; phosphorus 5-10 
p-p.m.; potassium 20-40 p.p.m. and calcium near 200 
p.p.m. To increase the nitrate level, feed one pound 
of ammonium sulfate per 100 sq. ft. of area, and to 
bring up the potassium, apply muriate of potash not to 
exceed | pound per 100 sq. ft. If phosphorus is needed, 
apply mono-calium phosphate at the rate of | pound 
per 100 sq. ft. 
A liberal application of calcium sulfate (gypsum), 
5 pounds per 100 sq. ft., after steam sterilization wil 
prevent injury to young roots. High phosphorus also 
reduces toxicity after sterilization. 
In the cooler weather and shorter days of September, 
omit the nitrogen if the plants are growing freely. The 
mum assimilates more aiaaanae and potassium dur- 
ing the time of bud initiation. Therefore, it is desirable 
to apply a complete fertilizer shortly after the buds 
are visible. 
Soluble Salts 
Soluble salts are chemical compounds consisting of an 
acid part (ion) and a basic part (ion). For example, 
common table salt, sodium chloride, consists of one ion 
of chloride and one of sodium. Chloride is an acid- 
forming ion, and sodium a basic or alkali-forming ion. 
The two combine in chemically equivalent quantities to 
form a neutral salt. Other common acidic ions are 
sulfate, nitrate, bicarbonate and phosphate. Other 
common basic ions are calcium, magnesium, potassium 
and ammonium. Any basic ion may combine with any 
acidic ion giving rise to a great variety of salts. 
All plant nutrients which are absorbed by plants 
from the soil or from culture solutions are i ae 
in the form of salts or their constituent ions. All organic 
materials become "'mineralized' through decay proc- 
esses, and the nutrients in them are converted into 
salts before being absorbed by plants. Some salts con- 
tain plant nutrients and are beneficial in the small 
quantities required for plant growth. Others contain 
no nutrients. All salts are harmful beyond the small 
quantity required for plant growth. A little is bad, 
more is worse, up to the point where plants will be 
killed. Salts are found in most water and are applied 
as fertilizer. Improper watering may permit a con- 
centration into the harmful range. Instruments called 
Wheatstone's bridges are available which measure 
total soluable salts in terms of electrical conductivity or 
conductance. Many laboratories of the Agricultural 
Extension Service are equipped with Solubridge instru- 
ments for use in assisting with soluble salt problems. 
It has been found that when planting rooted cuttings, 
the Solubridge readings should not be higher than 
40, while established plants do not withstand readings 
of 100 without showing some harmful effects. To remedy 
excess soluble salts, apply 2 to 3 gallons of water per 
sq. ft. and leach out this high salt content. 
Laboratory Procedure Used in 
Developing Disease Free Cuttings 
61 
