PESTICIDE RESIDUES IN FOOD - 1984
Sponsored jointly by FAO and WHO
EVALUATIONS 1984
The monographs
Data and recommendations of the joint meeting
of the FAO Panel of Experts on Pesticide Residues
in Food and the Environment and the
WHO Expert Group on Pesticide Residues
Rome, 24 September - 3 October 1984
Food and Agriculture Organization of the United Nations
Rome 1985
CYHALOTHRIN
RESIDUES IN FOOD AND THEIR EVALUATION
USE PATTERN
Cyhalothrin is a pyrethroid insecticide with a high level of
activity against a wide range of Lepidoptera, Hemiptera, Diptera and
Coleoptera spp. It also has miticidal activity. The compound is a
stomach, contact and residual insecticide. It shows adulticidal,
ovicidal and, particularly, larvicidal activity. It is also extremely
effective against a great number of insects resistant to standard
treatments such as organochlorines and organophosphates.
Like other photostable synthetic pyrethroids, cyhalothrin is
relatively stable to degradation in sunlight. This allows it to be
used as a practical tool in agriculture. Cyhalothrin is not plant
systemic and has very little fumigant or translaminar activity.
The miticidal activity of cyhalothrin is seen as being
particularly useful as an adjunct to the control of other insects,
which the compound provides in tree fruits such as apples. When used
for lepidopterous pest control, it greatly reduces the risk of mite
build-up that is experienced with some other insecticides in top fruit
and can reduce, or even eliminate, the need for mite sprays.
Owing in part to its short persistence in soil and in part to a
lack of systemic effect, cyhalothrin is of only limited value when
used as a soil insecticide. It can, however, give useful control of
cutworms when applied as a crop/ground spray. Cyhalothrin has no
molluscicidal or nematicidal activity.
Preventive treatments are generally more effective than curative
treatments against major pests, such as boring caterpillars or leaf
miners. A programme of sprays is usually required, particularly during
more active growth stages of the plant and when the potential for
re-infestation remains high. Best results are obtained using good
spray cover, particularly when cyhalothrin is used during the early
development stages of the pest.
RESIDUES RESULTING FROM SUPERVISED TRIALS
Cyhalothrin residues have been determined in a range of crops
taken from supervised trials in several different countries.
Samples from trials conducted outside the United Kingdom were
frozen and transported by air freight to laboratories in the United
Kingdom, where they were stored in a deep freeze (-20°C) until
required for analysis. Fresh samples from trials in the United Kingdom
were frozen upon receipt. Cyhalothrin residues in crops stored deep
frozen have been shown to be stable for a 12-month period (Swaine &
Sapiets, 1984).
Cyhalothrin residues were determined by gas chromatography using
an electron-capture detector, as described under "Methods of Residue
Analysis".
Pome Fruits
At rates of 20-40 mg/kg a.i. in the spray, or 40-80 g a.i./ha,
cyhalothrin gives excellent control of a complex of insects on apples,
including winter moth (Operophtera brumata), tortrix moths
(Archips podana and Adoxophyes orana), codling moth (Cydia
pomonella) , apple sucker (Psylla mali) and apple sawfly
(Hoplocampa testudinea) . A programme of at least three sprays per
season is normally required, with an interval of at least two weeks
between the last application and first harvest. As an acaricide,
50-100 mg/kg a.i. in the spray, or at least 100 g a.i./ha, is needed
for economic control of fruit tree red spider mite (Panonychus ulmi)
and of Tetranychidae.
During 1982-83, supervised residue trials on apples or pears were
conducted in Cyprus, Japan, South Africa, Spain and the United
Kingdom, using either 5 percent W.P. or 10 percent E.C. formulations.
At rates needed for lepidopterous insect control, the maximum residue
level in apples immediately after application did not exceed
0.5 mg/kg. As in the cases of permethrin and cypermethrin (FAO/WHO,
1980) 1/, cyhalothrin levels on apples decline relatively slowly.
Nevertheless, at rates needed for lepidopterous insect control,
cyhalothrin levels were consistently below 0.2 mg/kg two weeks after
the last application (Table 1) (Swaine et al., 1983a,b,c,d).
Results of a trial on pears in Cyprus were also consistent with
these findings (Swaine et al., 1983e).
In a comparative trial in South Africa, cyhalothrin residue
levels on apples and pears were similar after various intervals in the
32 days following the application of a 10 percent E.C. formulation at
40 or 80 mg/kg a.i. in the spray, applied to "run-off" (Table 2)
(Swaine et al., 1983b; 1984).
Cabbage and Chinese Cabbage
At rates of approximately 10-20 g a.i./ha, cyhalothrin gives good
control of a range of insects on cabbage, including Spodoptera spp.,
cabbage loopers (Trichoplusia ni), cabbage moths and butterflies
(Plutella and Pieris spp.), aphids (Myzus and Brevicoryne
brassicae) and whitefly (Trialeurodes vaporarium). A programme of
sprays may be required, depending on the location, pest spectrum and
infestation pressure. An interval of two to four days between last
spraying and harvest is often possible; in some situations it may be
possible to observe an interval as long as seven days.
1/ See Annex 2 for FAO and WHO documentation
During 1982-83, trials were conducted in Spain, the United
Kingdom and the United States, using either a 5 percent W.P. or
10 percent E.C. formulation. Cyhalothrin was applied at two different
rates at each site and there was good correlation within each trial
between the initial residue found after the last application and the
rate of application. There was greater variation in initial residues
between sites. The data indicated over all that cyhalothrin has a
relatively shorter initial half-life, of two to five days, on cabbages
than on apples. This is consistent with the earlier findings with
permethrin and cypermethrin (FAO/WHO 1980). Levels on cabbage were
generally below 0.2 mg/kg within a few days of spraying (Table 3)
(Sapiets, 1984a,b; Swaine et al., 1983f). There was no obvious
build-up in cyhalothrin residue levels on cabbage after repeated
applications (Sapiets, 1984b).
Other Crops
Cyhalothrin residues data are also available on Swiss chard,
peaches, grapes, maize, sorghum and tea (Sapiets, 1984c).
FATE OF RESIDUES
In Plants
14C-cyclopropyl-labelled cyhalothrin, containing approximately
10 percent of the 14C-cyclopropyl-labelled 1RS-cis-E form of
the molecule, was formulated as a 10 percent emulsifiable concentrate
formulation, diluted with water and spotted onto young growing apple
fruits. A polythene shelter erected over the tree protected the fruits
from direct rainfall but allowed transmission of the ultraviolet
radiation present in sunlight. The surfaces of the apples chosen for
treatment were those exposed directly to the predominant direction of
incident sunlight. After 56 days, at least 89 percent of the
radioactivity recovered from treated peel was due to unchanged
pyrethroid. The remainder of the radioactivity extracted with aqueous
acetone was polar; acid hydrolysis produced an organosoluble fraction,
which contained almost entirely 1RS-cis-3-(Z-2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylic acid,
although the presence of about 14 percent of this radioactivity
in the 1RS-trans form was evidence of a certain amount of
photoisomerization. The applied radioactivity was not translocated
away from the treated area of peel. The flesh from below the treated
area of fruit harvested at 28 and 56 days after treatment contained
less than 1 percent of the recovered radioactivity (Hall & Leahey,
1979).
14C-cyclopropyl-labelled cyhalothrin, prepared as an aqueous
dilution of a 10 percent E.C. formulation, was spotted at a rate
equivalent to approximately 25 g a.i./ha onto the leaves of cabbage
plants grown in pots. The plants were exposed to sunlight but were
protected from rainfall and covered overnight with a polythene cover.
TABLE 1. Cyhalothrin Residues in Apples from Supervised Trials
Country/ Formulation Rate Volume No. Interval last Residues (mg/kg)
year (g a.i./ha) of spray spray to
(l/ha) sampling (days) R157836 Rl19321 Total
Japan 1 5% W.P. 25 mg/kg a.i. 6 300 3 7 0.09, 0.10 0.06, 0.07 0.15, 0.17
1982 in spray 14 0.05, 0.05 0.03, 0.04 0.08, 0.09
(0.0025%) 21 0.02,<0.006 0.01,<0.004 0.03,<0.01
3 000 3 7 0.09, 0.09 0.07, 0.07 0.16, 0.16
14 0.08, 0.08 0.06, 0.06 0.14, 0.14
21 0.09, 0.06 0.06, 0.04 0.15, 0.10
Spain 10% E.C. 25 mg/kg a.i. Sprayed 4 0 0.06 0.04 0.10
1982 in spray to "run- 1 0.05 0.04 0.09
(0.0025%) off" 3 0.04 0.03 0.07
7 0.03 0.02 0.05
50 mg/kg a.i. Sprayed 4 0 0.07 0.06 0.13
in spray to "run- 1 0.07 0.05 0.12
(0.005%) off" 3 0.07 0.06 0.13
7 0.04 0.03 0.07
South 10% E.C. 40 mg/kg a.i. Sprayed 1 0 0.06 0.05 0.11
Africa in spray to "run- 1 0.08 0.06 0.14
1982-83 (0.007%) off" 2 0.06 0.05 0.11
(80 g/ha) 4 0.07 0.05 0.12
8 0.07 0.06 0.13
16 0.06 0.05 0.11
32 0.02 0.02 0.04
TABLE 1. (continued)
Country/ Formulation Rate Volume No. Interval last Residues (mg/kg)
year (g a.i./ha) of spray spray to
(l/ha) sampling (days) R157836 Rl19321 Total
80 mg/kg a.i. Sprayed 1 0 0.21 0.16 0.37
(.0.008%) to "run- 1 0.24 0.19 0.43
(160 g/ha) off" 2 0.24 0.18 0.42
4 0.18 0.13 0.31
8 0.14 0.10 0.24
16 0.11 0.08 0.19
32 0.12 0.09 0.21
United 10% E.C. 45 g a.i./ha 560 1 0 0.03 0.02 0.05
Kingdom 2 7 0.02 0.01 0.03
1982 14 <0.006 <0.004 <0.01
45 g a.i./ha 560 1 0 0.04 0.03 0.07
7 0.02 0.02 0.04
14 0.01 <0.004 <0.014
1x18 g a.i./ha 560 3 14 0.04 0.02 0.06
and
2x45 g a.i./ha
1x24 g a.i./ha 560 2 40 0.01 0.01 0.02
and
1x60 g a.i./ha
25 mg/kg a.i. Sprayed 2 0 0.05, 0.12 0.04, 0.09 0.09, 0.21
in spray to "run- 1 0.06, 0.11 0.05, 0.08 0.11, 0.19
(50 g/ha) off" 3-4 0.04, 0.12 0.03, 0.09 0.07, 0.21
7 0.04, 0.08 0.04, 0.06 0.08, 0.14
TABLE 1. (continued)
Country/ Formulation Rate Volume No. Interval last Residues (mg/kg)
year (g a.i./ha) of spray spray to
(l/ha) sampling (days) R157836 Rl19321 Total
50 mg/kg a.i. Sprayed 2 0 0.12, 0.11 0.10, 0.09 0.22, 0.20
in spray to "run- 1 0.12, 0.16 0.09, 0.13 0.21, 0.28
(100 g/ha) off" 3-4 0.08, 0.17 0.06, 0.12 0.14, 0.29
7 0.07, 0 12 0.06, 0.09 0.13. 0.21
1 The duplicate results are on replicate samples from the same trial
2 The duplicate results are on single samples from two different trials in different locationsœ
TABLE 2. Cyhalothrin Residues in Apples and Pears from Supervised Trials, South Africa1
Application
Interval spray Total residues
Rate Volume No. to sampling (mg/kg)
(mg/kg a.i.) of spray (days) Apples Pears
40 Sprayed to 1 0 0.11 0.12
"run-off" 1 0.14 0 17
(80 g/ha) 2 0.11 0.16
4 0.12 0.16
8 0.13 0.16
16 0.11 0.14
32 0.04 0.07
80 Sprayed to 1 0 0.37 0.29
"run-off" 1 0.43 0.29
(160 g/ha) 2 0.42 0.32
4 0.31 0.25
8 0.24 0.21
16 0.19 0.17
32 0.21 0.14
1 All trials done in 1982 using 10 percent E.C. formulation
TABLE 3. Cyhalothrin Residues in Cabbage from Supervised Trials
Residues (mg/kg)
Country/ Rate Volume No. Interval last
year Formulation (g a.i./ha) of spray spray to R157836 Rl19321 Total
used (1/ha) sampling (days) Cyhalothrin
Spain 10% E.C. 20 300 4 0 0.44 0.31 0.75
1983 3 0.25 0.18 0.43
(on 7 0.18 0.13 0.32
Chinese
cabbage) 40 300 4 0 0.58 0.43 1.0
3 0.28 0.21 0.49
7 0.28 0.20 0.48
United 1 5% W.P. 75 3 000 2 14 - - 0.06, 0.08
Kingdom 3 0 - - 0.36, 0.34
1983 3 0.01, 0.04 0.01, 0.03 0.02, 0.07
7 0.01, 0.01 0.01, 0.004 0.02, 0.01
14 <0.006,<0.006 <0.004,<0.004 <0.01,<0.01
United 10% E.C. 10 225 6 0 0.07 0.04 0.11
States 1 0.06 0.03 0.09
1982 3 0.02 0.01 0.03
7 0.01 0.01 0.02
20 225 6 0 0.20 0.13 0.33
1 0.05 0.04 0.09
3 0.05 0.02 0.07
7 0.04 0.03 0.07
1 The duplicate results are on single samples from two different varieties on the same site sprayed at the same time.
After six weeks, 54 percent of the radioactivity was still present as
the intact pyrethroid. Some photoisomerization was indicated by the
interconversion of cis and trans isomers and of Z and E
isomers, although even after six weeks the combination of the two
enantiomer pairs making up cyhalothrin itself still predominated.
Cyhalothrin was degraded on cabbage leaves to polar compounds that
could be converted to organosoluble materials by acid hydrolysis.
1RS-cis- and 1RS-trans-3-(ZE-2-chloro-3,3,3-trifluoroprop-
1-enyl)-2,2-dimethylcyclopropanecarboxylic acids were the major
hydrolysis products, accounting for approximately 8 percent of the
radioactivity present (Curl & Leahey, 1983).
A cabbage plant was sprayed eight times at weekly intervals with
14C-cyclopropyl-labelled cyhalothrin, prepared as an aqueous dilution
of a 10 percent E.C. formulation, at a rate of 25 g a.i./ha. The plant
was left exposed to all weather conditions without shelter. One week
after the final spray, total radioactive residues in the outer leaves
and in the heart were 1.13 and 0.003 mg cyhalothrin equivalents/kg,
respectively, equivalent to 0.44 mg/kg on a whole cabbage basis; 80
percent of the radioactive residue in the outer leaves was unchanged
cyhalothrin and the pattern of metabolism was the same as for a single
application. The effects of photoisomerization were less marked in
this study than in the one involving the single application, probably
because most of the residues resulted from the final spray (Curl &
Leahey, 1983).
Evidence for the fate of the alcohol part of the molecule after
ester hydrolysis was provided by studies on the structurally-similar
compound cypermethrin, which were reviewed by the 1979 meeting and in
which 14C-benzyl-labelled material was used. In outdoor studies on
lettuce and apples, cypermethrin itself was still the dominant part of
the residue after three weeks. On apple fruit and lettuce, most of the
remainder of the radioactivity was present as polar materials, which
individually were in too small amounts for detailed study. On apple
leaves, compounds identified included 3-phenoxybenzoic acid,
3-(4-hydroxyphenoxy)benzoic acid, 3-phenoxybenzaldehyde and
3-phenoxybenzyl alcohol, either free or as conjugates.
Samples of apples and peaches from trials in Japan have been
analysed for residues of cyhalothrin, 3-phenoxybenzoic acid,
3-(4-hydroxyphenoxy)-benzoic acid and 1RS-cis-3-(Z-2-chloro-
3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylic acid
(HCVA). In all cases, residues of the metabolites were very much
smaller than those of cyhalothrin (Table 4) (Sapiets, 1984d; Swaine,
Sapiets et al., 1983a, h).
TABLE 4. Cyhalothrin and Metabolite Residue in Apples and Peaches, Japan 1
Residue (mg/kg)
Crop Interval last
application to Cyhalothrin HCVA 3-phenoxy- 3-(4-hydroxyphenoxy)-
sampling benzoic acid benzoic acid
(days)
Apple 7 0.16 0.02 <0.02 <0.05
14 0.14 <0.01 <0.02 <0.05
21 0.13 0.01 <0.02 <0.05
7 0.16 0.04 <0.02 <0.02
14 0.09 0.02 <0.02 <0.02
21 <0.02 <0.01 <0.01 <0.02
Peach 7 0.30 0.05 <0.02 <0.02
14 0.25 0.08 <0.02 <0.05
21 0.12 0.03 <0.02 <0.02
7 0.30 0.07 0.02 <0.02
14 0.22 0.03 <0.02 <0.02
21 0.12 0.02 <0.02 <0.02
1 All trials done in 1982 using a 5 percent W.P. formulation
In Soil
At residue levels that are likely to occur under normal field
conditions, cyhalothrin is degraded rapidly in soil. When a sandy loam
soil was treated with 14C-cyclopropyl-labelled cyhalothrin, only 28
percent of the recovered radioactivity was present as cyhalothrin
after five weeks incubation under aerobic conditions; 30 percent was
evolved as 14C-labelled carbon dioxide and 3.5 percent of the
recovered radioactivity was due to 1RS-cis-3-(Z-2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropane-carboxylic acid.
Approximately 19 percent of the radioactivity was not extracted using
acetonitrile at room temperature followed by soxhlet extraction with
aqueous acetonitrile (Bewick & Zinner, 1981).
Using soil thick-layer descending chromatography in three soils,
cyhalothrin was shown to have low mobility in soil which was
considerably less than that of atrazine (Stevens & Poole, 1981).
In Water
14C-cyclopropyl-labelled cyhalothrin was incubated with river
water/sediment mixtures contained in quartz flasks. The flasks were
either exposed to sunlight or were maintained under dark conditions by
covering them with aluminium foil. In the dark, degradation of
cyhalothrin was slow (over 80 percent unchanged after 32 days).
However, when exposed to sunlight the cyhalothrin degraded with a
half-life of approximately 20 days in both river water/sediment
mixtures. The rate at which the parent compound was lost from the
aqueous phase was, however, much more rapid than its rate of
degradation in the whole water/sediment system. This was due to the
ready absorption of cyhalothrin onto the sediment. The major
degradation process was simple ester cleavage of the molecule,
producing 1RS-cis- and 1RS-trans-3-(ZE-2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylic acids. After
32 days irradiation, the compounds together represented 36 to 47
percent of the radioactivity applied to the water/sediment systems.
Some photoisomerization also occurred (Hall & Leahey, 1983).
In Processing
Cyhalothrin residues on cabbage are present mostly in the outer
leaves. Therefore, the extent to which these outer leaves are removed
before consumption has a major bearing on residues on cabbage at the
point of consumption. In a field residue trial in the United Kingdom,
cyhalothrin residues were found to be mainly in the seven outermost
leaves (Sapiets, 1984b).
In the cabbage metabolism work reviewed above, one week after the
last of eight weekly sprays of 25 g a.i./ha, total radioactive
residues in the outer leaves and in the hearts were 1.13 and 0.003 mg
cyhalothrin equivalents/kg, respectively, equivalent to 0.44 mg/kg on
a whole cabbage basis. Eighty percent of the radioactivity in the
outer leaves was due to unchanged cyhalothrin (Curl & Leahey, 1983).
Cyhalothrin levels on cabbage treated in Japan and from which
leaves had been stripped before the crop was submitted for analysis
were also extremely small (<0.01 mg/kg) (Swaine et al., 1983g).
A comparison of cyhalothrin residues from two concurrent trials
with the same 10 percent E.C. formulation, applied at the same rates
in the same location in Spain on Chinese cabbage, from which outer
leaves were not stripped, and on common cabbage, from which leaves
were stripped before the crop was submitted for analysis, showed very
much larger residues in the former (Table 5) (Sapiets, 1984a,e).
METHODS OF RESIDUE ANALYSIS
The crops were prepared for analysis by mincing or chopping until
a homogeneous sample was obtained. For small fruits the whole sample
was prepared; large vegetables, e.g. cabbage, were quartered and
opposite quarters taken. Samples were extracted using 50 percent
acetone in hexane and the extracts washed with water. Co-extractives
were removed by liquid-liquid partition chromatography where necessary
(crops requiring this clean-up include cabbage). All crops were
cleaned up using Florisil adsorption chromatography. Final
quantitative determination of cyhalothrin residues was by gas-liquid
chromatography, using electron-capture detection. The limit of
determination for total cyhalothrin isomers is 0.01 mg/kg.
An internal standard procedure was used for the quantitative
measurement of residues. The internal standard compound, a synthetic
pyrethroid analogue in which a bromine atom is substituted for the
chlorine atom on the vinyl side chain, was added to each sample prior
to extraction. The response ratio of cyhalothrin to internal standard
in the final extract of each sample was used for quantitative
measurement of residues. The use of the internal standard allows the
size of the sample aliquot processed through the method to be reduced
without loss of accuracy. In addition, as the recovery of pyrethroid
is effectively monitored for each sample, the precision of the assay
is significantly improved using this procedure. Calibration curves
plotted for amount of cyhalothrin versus response ratio of cyhalothrin
to internal standard gave linear regression lines (correlation
coefficient r > 0.99) with an intercept passing through the origin
(Sapiets & Swaine, 1983).
APPRAISAL
Cyhalothrin is a new photostable synthetic pyrethroid insecticide
and acarcide with a level of activity, demonstrated by required dose
rates, between deltamethrin and the other related compounds permethrin
and cypermethrin. Since it is not systemic, residue levels depend on
the amount applied and the efficiency of application.
TABLE 5. Cyhalothrin Residues on Cabbage and Chinese Cabbage, Spain 1
Application
Residues (mg/kg)
Crop Rate Volume No. Interval last
(g a.i./ha) of spray spray to R157836 Rl19321 Total
(1/ha) sampling (days) Cyhalothrin
Cabbage (wrapper 20 300 4 0 0.03 0.02 0.04
leaves stripped 3 0.01 0.01 0.02
off before 7 0.01 0.01 0.02
analysis)
40 300 4 0 0.02 0.01 0.03
3 0.04 0.02 0.06
7 0.01 0.01 0.01
Chinese cabbage 20 300 4 0 0.44 0.31 0.75
(wrapper leaves 3 0.25 0.18 0.43
not stripped off 7 0.18 0.13 0.32
before analysis)
40 300 4 0 0.58 0.43 1.0
3 0.28 0.21 0.49
7 0.28 0.20 0.48
1 All trials done in 1983 using 10 percent E.C formulation
The uses considered by the meeting were on pome fruit and cabbage
only. The proposed GAP is up to 100 mg/l (0.01 percent) in the spray,
100 g a.i./ha, per application on apples and pears with a 14-day
interval between the last application and harvest. Rates are
approximately 10-20 g a.i./ha on cabbage, up to six applications are
used with an interval of 2-4 days between the last application and
harvesting.
The meeting noted that the maximum rate of application used in
the trials on pome fruit was not well defined. The highest
concentration used was 80 mg/l in the spray; this sprayed to 'run-off'
might equate with a high-volume spray of 2 000 l/ha, i.e. 160 g
cyhalothrin/ha. Initial deposits from a single application indicated
that residues up to 0.5 mg/kg could be expected; this decreased to
about 0.2 mg/kg in 14 days. In several other trials, at lower spray
concentrations, residues did not exceed 0.2 mg/kg as initial deposits,
even when very high volumes were applied and the total rate of
application approached 160 g a.i./ha. Although on some occasions some
residues diminished with time, several trials showed virtually no
decrease in residues over the first 14 days after application. The
meeting concluded that more attention should be given to initial
deposits and that residues could reach 0.5 mg/kg, especially at the
higher rates and volumes needed to control fruit tree red spider mite.
This estimate of the maximum residue level was considered suitable for
establishing a temporary MRL and should be reviewed in 1986 in the
light of more residues data.
The data on cabbage were considered inadequate for the estimation
of a maximum residue level.
RECOMMENDATIONS
The following maximum residue level was estimated and recommended
as suitable for use as a temporary MRL.
Temporary MRL Preharvest interval on which
(mg/kg) recommendation is based (days)
Pome fruit 0.5 14
FURTHER WORK OR INFORMATION
Required (by 1986)
1. Further residues data on pome fruit.
2. Further information on GAP in use of cyhalothrin on pome fruit.
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PP563B008 submitted by ICI Plant Protection Division to FAO.
(Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues in apples
1983c from Spain in 1982. Residue Data Report No. PP563B007
submitted by ICI Plant Protection Division to FAO.
(Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues in apples
1983d from UK in 1982. Residue Data Report No. PP563B001 submitted
by ICI Plant Protection Division to FAO. (Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues in pears from
1983e Cyprus in 1982. Residue Data Report No. PP563B005 submitted
by ICI Plant Protection Division to FAO. (Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues in cabbage
1983f from USA in 1982. Residue Data Report No. PP563B006
submitted by ICI Plant Protection Division to FAO.
(Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues in cabbage
1983g from Japan in 1982. Residue Data Report No. PP563B002
submitted by ICI Plant Protection Division to FAO.
(Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues in peaches
1983h from Japan in 1982. Residue Data Report No. PP563B004
submitted by ICI Plant Protection Division to FAO.
(Unpublished)
Swaine, H., Sapiets, A. & Burke, S. Cyhalothrin residues n pears
1984 from South Africa in 1982-3. Residue Data Report No.
PP563B013 submitted by ICI Plant Protection Division to FAO.
(Unpublished)