Agriculture Reference
In-Depth Information
General Watering Procedure
Provide water to all tests as needed to insure a moist environment for emergence and growth. Pigmentation
tests for bentgrass, lettuce and soybean seedlings should be watered with Hoagland's No. 1 nutrient solution
every fourth day and ordinary water on other days. Do the same for oat and wheat seedlings for coleoptile
and stem pigmentation evaluation, except that Hoagland's solution should lack phosphorus. Sorghum and
corn seedlings grown in sand for pigmentation evaluation should be watered every day and Hoagland's
solution should not be applied.
Hoagland's nutrient solutions can be made by the following procedure. Prepare stock solutions of
proper molarity of each of the compounds needed for a speciic nutrient solution. Add the designated
volume (ml) of each solution to one liter of distilled water.
ml added/
Hoagland's No. 1
Molarity
Compound
liter of water
1.0
KH 2 P0 4
1
1.0
KN0 3
5
1.0
Ca(N0 3 ) 2
5
1.0
MgS0 4
2
ml added/
Hoagland's No. 1 lacking phosphorous
Molarity
Compound
liter of water
1.0
Ca(N0 3 ) 2
4
1.0
MgS0 4
2
1.0
KN0 3
6
Add 1.0 ml of minor elements and 1.0 ml of 0.5% iron tartrate solution or other suitable iron salt to each
liter of nutrient solution
Minor Elements
g/l of water
H 3 B0 3
2.86
MnCl 2 . 4H 2 0
1.81
ZnS0 4 . 7H 2 0
0.22
CuS0 4 . 5H 2 0
0.08
H 2 Mo0 4 . H 2 0
0.02
Water seedlings growing in potting soil with Hoagland's No. 1 nutrient solution as needed. Since pot-
ting soil usually contains a supply of nutrients, the seedlings may not require nutrient solution more often
than every fourth day.
When testing soybean seedlings for metribuzin sensitivity, apply 0.30 ppm of metribuzin dissolved in
Hoagland's No. 1 nutrient solution directly to the surface of the lat daily at the rate of 0.37 ml per cm of lat
surface. Begin application when unifoliate leaves are fully expanded. On the tenth day, increase the rate to
0.56 ml/cm 2 .
Search WWH ::




Custom Search