See Varietal Publication No. CXXXIX, April,
1990
We are requesting an amended description for
the variety DK-189 (VS-754) based on data from additional testing. DK-189
was originally classifies NOT TESTED, we feel that a moderately resistant
rating for stem nematode and a resistant rating for blue alfalfa aphid
more accurately reflects the DK-189 reaction to these pests.
STEM NEMATODE
Test conduscted by Crop Characteristics at Northfield, MN
Resistance Year Syn. Unadjust. Adjust. Score or
Variety Class Tested Gen. %R %R A.S.I.
This variety MR 1990 2 24 3.4
1. Lahontan R 52 2.6
2. Ranger S 9 4.0
Unadjust. Score or
%R A.S.I.
3.
Test Mean: 40.0 3.12
L.S.D. (.05) 15.1 0.49
C.V. (%) 29.5 12.2
Scoring system used: 16 wk old inoculated seedling
scored 1-5, (1+2)=R
BLUE ALFALFA APHID
Test conducted by A.A. Zarrabi at Oklahoma State University
Resistance Year Syn. Unadjust. Adjust. Score or
Variety Class Tested Gen. %R %R A.S.I.
--------------------------------------------------Oklahoma------------
This variety R 1990 2 25.9 38.6 3.75
1. CUF 101 HR 30.2 45.0 3.70
2. Arc S 2.5 3.8 4.30
3.
Test Mean: 18.0 26.9 3.95
L.S.D. (.05) 5.7 8.4 .17
C.V. (%) 22.0 22.0 3.0
Scoring system used: (1-5) 5=dead, (1+2+3)=resistant