| PLANT CULTURE
Greenhouse
| Container........... |
Bench, flat,or pot deep enough to allow root
development |
|
Media ............... |
Sand, soil or potting mix |
|
Temp/light ........ |
24 to 30°C; 16+ hr daylength |
|
No. of plants ..... |
25+ per replication |
|
No. of reps ........ |
3 to 6 replications |
|
Other ............... |
Spray and fertilize as necessary |
FIELD ESTABLISHMENT
| Location
........... |
Transplant 8-12 week old plants to
the field in late May or early June; direct seeding with
hand thinning also acceptable |
|
Spacing ............ |
0.3 to 0.4m x 0.6 to 1.0m |
|
Culture. ............ |
Maintain vigorous growth, control weeds
and insects |
|
Test length ....... |
Scores recorded in the spring, one year
after establishment |
|
Plant counts ...... |
Plant counts should be taken after last
cut prior to first severe frost |
|
Test location ...... |
Test sites should be limited to areas
where the check varieties in classes 5-6 are dead or
severely injured and where there will be clear
differences between check varieties in class 2 vs. class
4. |
CLIPPING MANAGEMENT
Nurseries should be intensively managed in the
establishment year. They should be clipped at early to
mid bud stage with a final clipping in mid September in
MN or WI. Under this cutting regime the plant enters the
winter in a stressed condition, allowing for more
consistent winter injury in moderate winters. Local
experience will provide information on which clipping
dates provide the greatest separation among varieties.
RATING
-
No injury, plant has uniform, symmetrical appearance,
all shoots are about equal in length.
- Some injury, the plant is symmetrical,
but regrowth is slightly uneven.
- Significant injury, regrowth varies in length,
reduced vigor.
- Severe injury, plant has sparse shoots, regrowth
is very irregular, poor vigor.
- Dead plant
An average score (ASI) can be calculated for each
cultivar. A winter survival rating (1-6) can be assigned
based on the ASI relative to the standard check
cultivars.
CHECK CULTIVARS
| Variety |
Winter Survival
rating |
Typical
ASI |
| ZG 9830 |
1 |
1.6 |
| 5262 |
2 |
2.2 |
| WL325HQ |
3 |
2.9 |
| G-2852 |
4 |
3.6 |
| Archer |
5 |
4.0 |
| Cuf 101 |
6 |
4.8 |
SCIENTISTS WITH EXPERTISE
Name....................Mark McCaslin
Address................Forage Genetics International
P.O. Box 415
Prior Lake MN 55372
Email....................mccaslin@forage-genetics.com
Name...................Tim Woodward
Address...............Washington State University
Franklin County Courthouse
1016 N 4th
Pasco WA 99301-3706
Email.................. woodward@wsu.edu
Name...................Dan Undersander
Address...............Department of Agronomy
1575 Linden Drive
Madison WI 53706
Email.................. djunders@facstaff.wisc.edu
HELPFUL INFORMATION
A minimum of two location years is required for this test
because of possible variation in the nature of winter
injury over years and locations.
A successful test must show a significant difference
(p=.95) between the class 2 and class 4 check cultivars.
The class 6 checks must have an ASI of 4.6 or higher.
Care should be taken to read the winter survival test
after all the plants have broken dormancy. Readings taken
too early may underestimate winter survival in some
dormant lines.
Degree of severity of this test may be increased by snow
removal (2).
REFERENCES
1. Knipe, W.C., C. Fox, F. Stanley, and J. Magsam. 1989.
Relationship between cold injury and fall growth in
alfalfa. Proc. 21st Central Alfalfa Imp. Conf. p.26
2. McKensie, J.S. and J.G.N. Davidson. 1984. A stress test for assessing the winterhardiness of alfalfa
in
nortwestern Canada. Can. J. of Plant
Sci. 64:917-924.
3. Peterson, M, D. Barnes, W. Knipe, M.
McCaslin, J. Moutray, D. Viands, and T. Woodward. 1989. A
seven
location study of the relationship between fall
dormancy and winterhardiness in alfalfa. Proc. 21st
Central
Alfalfa Imp. Conf. p22-23.
4. Sulc, R.M., K.A. Albrecht and S.H. Duke. 1989. Cold
tolerance of nine alfalfa cultivars varying in degree of
fall dormancy. Proc. 21 st Central Alfalfa Improvement
Conf. p24-25.
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