SECOND SCHEDULE
(Regulations 7, 8, 10 and 11)
STANDARDS FOR CERTIFICATION OF POTATO SEED
QUALITY
CLASS
(Code)
S1 (S2, S3)
SE
E1
E2
A
B
FIELD INSPECTION
Defect
Index
Isolation
(highest
(metres)
value)
150
1
100
4
100
8
100
8
100
12
50
30
VIRUS
POST
CONTROL
Maximum
severe virus
diseases
%
0.1
0.8
-
TUBER
CONTROL
CONTROL
Defect
Index
(highest
value)
10
10
10
10
15
20
GROWING
Defect
Index
(highest
value)
3
8
15
15
-
NOTES:
Field inspection
1.
The isolation refers to the distance between the potato crop for certification and
potato crops of lower quality classes or volunteer potato plants. Between different cultivars
of the same quality class the isolation shall be at least 5 metres.
2.
A potato crop will be considered heavily infested with aphids if there are more than
150 per 100 leaves taken from the lower half of a plant. Provided that haulm destruction of
a heavily infested crop is carried out within seven days from the date of discovering by
inspection, it may be cleared by field inspection.
3.
Undesirable plants shall be cleared away as soon as possible by removing both the
haulms and the tubers to a distance of at least 30 metres from every edge of the field.
4.
Diseased plants, plants of other cultivars and off type plants shall be recorded as
percentages by number; and the percentages found shall be multiplied by the appropriate
factors set out in note 5, and the various products so obtained shall be added together to give
the defect index for the particular field.
5.
The factors to obtain the defect index for a field inspection shall be as follows:
Defect
Leaf roll virus (PLRV)..................................................
Severe mosaic (PVY)....................................................
Black leg .......................................................................
Factor
10
8
3