Control of parasitic nematodes (A)

The use of the compound 2R,5R-dihydroxymethyl-3R,4R-dihydroxypyrrolidine (DMDP) ##STR1## or an acid addition salt thereof in controlling diseases caused by parasitic nematodes in plants or mammals.

FIELD OF INVENTION 
This invention relates to the control of diseases caused by parasitic 
nematodes in plants and mammals. 
PRIOR ART 
Since the early 1940s many chemical compounds active against plant 
parasitic nematodes have been available. These have often displayed 
undesirable toxic effects, for example the fumigant dibromochloropropane 
was withdrawn from the market in 1977, as it was thought to cause 
sterility in workers. During the 1960's fumigant type nematicides were 
largely superseded by granular systemic nematicides. These have been in 
use since then, a representative compound being oxamyl. These compounds 
are mainly oximecarbamates or organophosphate derivatives, and because of 
their toxicity have to be used in a strictly controlled manner. 
Accordingly it would be of benefit to have anti-nematode agents that are 
environmentally favourable, i.e. being non-toxic themselves and in their 
degradation products to non-target organisms. 
Additional prior art is referred to in a separate section after "Summary of 
the Invention", without which its context would not be clear. 
SUMMARY OF THE INVENTION 
The present invention provides the use of the compound 
2R,5R-dihydroxymethyl-3R,4R-dihydroxypyrrolidine (DMDP) 
##STR2## 
or an acid addition salt thereof, for use in controlling diseases caused 
by parasitic nematodes in plants, including crops, and in mammals. The 
invention also includes seeds, dressed, coated or impregnated with DMDP or 
a said salt thereof. 
The mechanism through which DMDP controls diseases caused by parasitic 
nematodes in plants may include any nematotoxic, nematostatic or 
anti-feedant effect on either adult or juvenile nematodes, inhibition of 
hatching of larval forms of nematodes, inhibition of root gall formation 
by nematode feeding, and further extends to any effect on a nematode that 
prevents its acquisition and/or transmission of plant viruses. 
DMDP is of natural origin and has been shown to display low phytotoxicity. 
ADDITIONAL PRIOR ART 
The discovery and extraction of DMDP is described by L. E. Fellows and G. 
W. J. Fleet in "Alkaloid Glycosidase Inhibitors from Plants" (In "Natural 
Products Isolation", G. H. Wagman and R. Cooper, Eds., Elsevier, 
Amsterdam, 1988, pp 540-565). In that review certain properties of DMDP, 
including insecticidal and insect deterrent activity, both as determined 
experimentally in feeding tests, are referred to. They are more clearly 
described in L. E. Fellows, Chemistry in Britain pp 842-844 (1987). These 
and other properties of DMDP are more extensively reviewed in Chapter 11 
of "Plant Nitrogen Metabolism", Plenum Publishing Corporation, 1989, pp 
395-427, by L. E. Fellows et al., especially at pages 410 (which refers to 
S. V. Evans et al., Entomol. Exp. Appl. 37, 257-261 (1985), 411 (which 
refers to the authors' own work and to W. M. Blaney et al., Entomol. Exp. 
Appl. 36, 209-216 (1984) and 415. See also L. E. Fellows et al., in 
"Swainsonine and Related Glycosidase Inhibitors", L. James, A. D. Elbein, 
R. J. Molyneux and C. D. Warren, Eds., Iowa State University Press, 1989, 
pp 396-416. The properties of DMDP referred to therein are not indicative 
of an anti-nematode effect. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A further advantage of DMDP lies in its mode of application when treating 
plants, especially crops. Many existing anti-nematode compounds are 
applied to the soil by broadcasting and incorporated using rotary 
cultivation. DMDP can be applied to the leaves, which, somehow produces an 
anti-nematode action in the roots of the plant. Possibly DMDP is 
translocated through the phloem, but this is not certain. Hence, DMDP may 
be applied in the form of a foliar spray instead of or in addition to the 
above-mentioned conventional means of application. A suitable dosage for 
soil application of DMDP is from at least 24 to at most 48 kg/ha at 20 cm 
depth. DMDP may also be applied by pre-treating plant seeds before sowing. 
DMDP is water-soluble and can therefore be applied without a surfactant or 
dispersing agent. The preferred concentration of active ingredient and 
rate of application depend on the mode of application and type of effect 
desired, e.g. they may differ for nematotoxicity and for inhibition of 
virus transmission. For foliar spraying it is suggested that normally the 
plants be sprayed with a solution containing 0.01 to 3-5 g./liter, 
preferably 0.01 to 1.0 g./liter of the active ingredient, until the spray 
runs off. Lower concentrations can be more useful in some circumstances, 
while higher concentrations will often be tolerable. 
DMDP displays its properties against a wide range of nematodes affecting 
plants, e.g. root-knot nematodes, cyst nematodes and virus-transmitting 
nematodes. Of particular note is its activity against the crop-damaging 
nematodes of the following genera: Meloidogyne, Globodera, Heterodera, 
Radopholus, Pratylenchus, Hirschmanniella, Scutellonema, Helicotylenchus, 
Tylenchus, Rotylenchus, Ditylenchus, Longidorus, Xiphinema. With regard to 
nematodes which infest mammals, DMDP is active against a wide range of 
helminthic nematodes, especially those of the following genera: 
Haemonchus, Teladorsagia, Nematodirus, Trichostrongylus, Dictyocaulus and 
Cooperia, particularly the species Haemonchus contortus and Teladorsagia 
circumcincta (previously classified as Ostertagia circumcincta). 
DMDP may be extracted from Derris elliptica Benth (Leguminosae) as 
described by A. Welter et al (Phytochem., 1976, 15, 747-749) or may be 
synthesized from D-glucose (Fuhrman et al., Nature, 1984, 307, 755-758); 
G. W. J. Fleet and R. W. Smith Tetrahedron Letters 26 (11) 1465-1468 
(1985) or from L-sorbose (P. Card et al., J. Org. Chem., 1985, 50, 
891-893). 
The above description of DHDP applies also to its acid addition salts, 
which can be any which are compatible with the intended use, e.g. 
agriculturally or veterinarily acceptable if the use is on plants or 
non-human animals respectively. Such salts can be made in the conventional 
way from the free base.

The following Examples illustrate the invention. "Tween" is a Registered 
Trade Mark. The units "ppm" signify a solution containing mg. of test 
compound per liter of water, in solutions for in vitro tests or in 
solutions for application to leaf surfaces. In the Examples, "DMDP" means 
the free base. 
EXAMPLE 1 
Virus Acquisition and Transmission Experiments 
The effect of a chemical on virus acquisition by a nematode vector was 
tested by exposing virus-free nematodes to a virus infected source plant 
in the presence of the test chemical. By comparing subsequent rates of 
virus transmission between treated and untreated nematodes the efficacy of 
the chemical can be determined. 
Whether a chemical affects the transmission of the virus can be determined 
by applying the chemical after the nematodes have acquired the virus, at 
the time they are about to feed on receptor plants. 
Experiments were performed in 25 cm.sup.3 plastic pots maintained in 
temperature controlled cabinets (Taylor & Brown, Nematol. medit., 1974, 2, 
171-175) using three week old seedlings of Petunia hybrida Vilm. The 
nematode/virus combination used was Xiphinema diversicaudatum vectoring 
Arabis Mosaic Virus. 
Petunia seedlings were potted in 22 ml of 3:1 sand/loam mixture. 
Forty-eight hours later the plants were inoculated with virus. After a 
further 24 hours 5 adult nematodes were added to each pot. (The test 
chemicals are added at this time if virus acquisition is being tested.) 
There were 10-15 replicates of each treatment. After 4 weeks the nematodes 
were extracted, and then added to the soil in which virus-free receptor 
plants were growing. (If virus transmission is being tested, the test 
chemicals are added at this time.) After a further 4 weeks the nematodes 
were again extracted and counted. The galls on the roots of the receptor 
plants were counted, the roots macerated and the sap applied to the leaves 
of Chenopodium quinoa plants (virus indicators). 
Twelve days later the C. quinoa plants were examined for the symptoms of 
the virus. There were 10-15 replicates of each treatment in both virus 
tests. In all cases controls were run in which no chemicals were added. 
The chemicals tested were DMDP (15 and 30 ppm) and a conventional 
nematotoxic compound oxamyl (7 ppm). 
Table 1a shows the effect of DMDP inhibiting root gall formation and per 
cent virus acquisition as compared to the control value. 
Table 1b shows the effect of DMDP inhibiting root gall formation and per 
cent virus transmission as compared to the control value. 
TABLE 1a 
______________________________________ 
Feeding and acquisition of Arabis Mosaic Virus 
by Xiphinema diversicaudatum 
Mean No. % virus No. of 
Treatment galls/root acquisition 
Replicates 
______________________________________ 
Control 1.5 33 15 
DMDP 15 ppm 0.5 (66%) 27 (18%) 15 
DMDP 30 ppm 0.4 (74%) 7 (79%) 14 
Oxamyl 7 ppm 
0.3 (80%) 0 (100%) 10 
______________________________________ 
() is % reduction in treatment compared to control 
TABLE 1b 
______________________________________ 
Feeding and transmission of Arabis Mosaic Virus 
by Xiphinema diversicaudatum 
Mean No. % virus No. of 
Treatment galls/root transmission 
replicates 
______________________________________ 
Control 1.5 64 11 
DMDP 15 ppm 
0.4 (74%) 72 (0%)* 10 
DMDP 30 ppm 
0.5 (66%) 18 (72%) 11 
Oxamyl 7 ppm 
0.7 (53%) 1 (98%) 11 
______________________________________ 
() is % reduction in treatment compared to control 
*treatment values higher than control 
EXAMPLE 2 
Hatch Test 
The hatch test examines the effect of the test chemicals on the egg hatch 
of Globodera pallida, the white Potato Cyst Nematode (PCN). 
Ten PCN cysts of uniform size and colour were put in a tube with 0.25 ml of 
the test compound solution (concs. 50 ppm and 100 ppm) and 0.75 ml of 
potato root diffusate. Root diffusate normally stimulates the juveniles to 
hatch from eggs in the cysts. There were 4 replicates of each treatment. 
Twice each week the liquid was removed and the number of hatched live and 
dead juveniles counted. The diffusate/chemical mixture was replenished 
after each nematode count. The tubes were stored at 19.degree. C. between 
counts. 
Table 2a shows the number of hatched juveniles, dead or alive, as the means 
from four replicates. The same data are also expressed as % effect. This 
Table shows that DMDP greatly decreases the number of juveniles hatching 
from cysts. 
This experiment was repeated using Globodera rostochiensis. Table 2b shows 
the % decrease in nematodes alive as compared to the control after 4 
weeks. From Table 2b, it can be seen that DMDP provides better effects 
than its acid salt. 
TABLE 2a 
______________________________________ 
Potato Cyst Nematode Hatch Test 
Hatched Juveniles 
Total Juveniles 
Live Dead Hatched 
Treatments (% increase)* 
(% increase)* 
(% decrease)* 
______________________________________ 
15 days exposure 
Control 698 16 714 
DMDP 50 ppm 
374 (46) 68 (325) 442 (38) 
DMDP 100 ppm 
203 (71) 91 (468) 294 (59) 
24 days exposure 
Control 1257 32 1289 
DMDP 50 ppm 
1056 (16) 112 (250) 1168 (9) 
DMDP 100 ppm 
601 (52) 150 (368) 751 (42) 
______________________________________ 
TABLE 2b 
______________________________________ 
Globodera rostochiensis cyst Hatch Test 
Conc (ppm) 
Test Compound 
220 100 50 25 12.5 6.25 3.12 
______________________________________ 
DMDP 32 38 52 52 41 0 10 
DMDP.HCl 0 0 0 0 27 31 21 
______________________________________ 
*All percentages are based on the control value 
EXAMPLE 3 
In Vitro Toxicity Test 
Groups of ten active adult Xiphinema diversicaudatum were hand-picked into 
individual watchglasses containing distilled water. At a given time the 
batches of nematodes were transferred into 1 ml aliquots of test compound, 
at various concentrations of the test compound, or for the control into 1 
ml of distilled water. There were three replicates of each treatment. At 
two intervals, viz. 48 and to 72 hours, the number of nematodes which were 
immobilised were recorded. They were considered as immobile if they failed 
to move when stimulated by prodding with a bristle. All tests were carried 
out at 5.degree. C. 
Table 3a shows the in vitro toxicity of DMDP over a range of 
concentrations. The percent immobility shown is corrected for control 
immobilities using Abbott's formula. Note the decrease in in vitro 
toxicity at 200 ppm and above. There is also an anomalous drop in toxicity 
at 25 ppm. 
In similar tests differences in toxicity to adult and juvenile nematodes 
were found. Table 3b shows the EC.sub.50 values (effective concentration 
required to immobilise 50% of the total number of nematodes) calculated 
from the results. 
This experiment was repeated, replacing X. diversicaudatum with Globodera 
rostochiensis. These results are shown in Table 3c, from which it can be 
seen that both DMDP and its acid salt are toxic to nematodes. 
TABLE 3a 
______________________________________ 
In vitro toxicity (adult Xiphinema diversicaudatum) 
Conc (ppm) 
10 25 50 100 200 500 
Test compound 
Percent immobility 
______________________________________ 
DMDP 48 hrs 15 5 11 35 0 0 
72 hrs 39 9 63 78 4 0 
______________________________________ 
TABLE 3b 
______________________________________ 
In vitro toxicity EC.sub.50 values (ppm) (Xiphinema diversicaudatum) 
Nematode stage 
Test duration 
Test compound 
tested 48 hrs 72 hrs 
______________________________________ 
DMDP Adult 87.0 44.0 
DMDP Juvenile 94.0 0.08 
______________________________________ 
TABLE 3c 
______________________________________ 
In vitro toxicity (Globodera rostochiensis) 
Conc (ppm) 
Test Compound 
2.5 10 25 50 100 
______________________________________ 
DMDP 25 37 44 50 37 
DMDP.HCI 88 56 50 50 50 
______________________________________ 
EXAMPLE 4 
Table 4 shows the dose-dependent activity of DMDP, using three tests: the 
split-pot experiment, the mini-pot experiment and the gall test 
experiment. 
a. Split-pot test 
The test shows whether the anti-nematode agents of the invention have a 
repellent or antifeedant effect on the nematodes and/or a nematicidal 
effect. 
A `split-pot`, i.e. a pot divided into two sections by a fine mesh material 
(see Alphey et al, Revue Nematol. 1988, 11(4), 399-404), was used. Each 
side was filled with 37 ml of soil (3:1 sand:loam mixture). Test compounds 
at the concentrations shown in Table 4 were added to the soil on the side 
in which a Petunia seedling had been planted. To the other side 100 adult 
Xiphinema diversicaudatum were added. There were 8 replicates of each 
treatment. 
After 21 days the two halves of the pot were separated and the nematodes 
were extracted from the soil in each half. Root galls were recorded on 
plants from the treated sides (Table 4a(i)). The numbers of live and dead 
nematodes from each half were counted and are shown in Table 4a(ii). 
Table 4a(i) shows that DMDP has an antifeedant action against nematodes at 
all concentrations tested. Table 4a(ii) shows that 80 ppm DMDP also 
possesses a nematotoxic effect in that on the plant side more nematodes 
were immobilised than in the pot to which oxamyl was applied. 
b. Mini-pot test 
This test identifies the nematicidal effect of the chemical in soil and its 
effect on nematode feeding behaviour. 
Petunia seedlings were planted in 22 ml of soil (sand:loam--3:1). The test 
compound solution or water (control) with 5 or 10 adult Xiphinema 
diversicaudatum were added to the soil. There were 10 replicates for each 
treatment. After 3 weeks the nematodes were extracted and the number of 
galls induced by nematode feeding on the roots were recorded and expressed 
as a mean per cent reduction of the control value. 
Table 4b shows that DMDP has a nematode repellent or antifeedant action. 
The most effective rate of DMDP was 25 ppm. 
c. Gall test 
In the gall test, tomato seedlings, stimulated to produce fine adventitious 
roots by removing the main root system, were planted in tubes containing 
25 g of fine, sieved dry sand, 350 Meloidogyne incognita (J2) and DMDP, in 
solution in water. The effect of DMDP on the ability of the nematodes to 
gall the plant roots was studied over a 10-12 day period. A water control 
was included in the test. There were 10 replicates of each treatment. 
Table 4c shows the results, from which it will be seen that DMDP is equally 
effective in the range 2.5-25 ppm but less effective at 50 and 240 ppm. 
The various tests indicate similar levels of activity of DMDP used between 
2.5 ppm and 100 ppm 
TABLE 4 
______________________________________ 
4a.(i) Split-pot Experiment (X. diversicaudatum/Petunia) 
Mean reduction galls/root 
Chemical/conc (ppm) 
as % of control 
______________________________________ 
DMDP/15 63 
DMDP/30 83 
DMDP/80 89 
______________________________________ 
______________________________________ 
4a.(ii) Mean numbers of nematodes recovered after 21 days in the 
planted and non-planted sides of the split pot 
(X. diversicaudatum/Petunia) 
Total Mobile Immobile 
Nematodes 
Nematodes Nematodes 
Test conc No No No 
Chemical 
(ppm) Plant plant 
Plant plant 
Plant plant 
______________________________________ 
DMDP 16 27 15 24 10 3 5 
DMDP 32 24 14 21 11 3 3 
DMDP 80 25 15 12 11 13 4 
Oxamyl 15 17 21 13 14 4 7 
Control -- 33 16 31 12 2 4 
______________________________________ 
______________________________________ 
4b. Mini-pot Experiment (X. diversicaudatum/Petunia) 
Mean reduction 
galls/root as % of control 
Chemical/conc (ppm) 
5 nematodes/pot 
10 nematodes/pot 
______________________________________ 
DMDP/8 70 -- 
DMDP/14 70 -- 
DMDP/25 94 72 
DMDP/50 72 83 
DMDP/100 65 100 
______________________________________ 
______________________________________ 
4c. Gall Test (M. incognita/Tomato) 
Chemical/conc (ppm) 
Reduction in galls/root as % of control 
______________________________________ 
DMDP/2.5 76 
DMDP/12.5 70 
DMDP/25 72 
DMDP/50 50 
DMDP/240 47 
______________________________________ 
EXAMPLE 5 
Mode of Application 
a) root application 
To test whether the anti-nematode agent would be more effective when taken 
up systemically by plants, the mini-pot test was adapted. The roots of 
Petunia hybrida were removed and the cut ends of the stems from which the 
newly formed roots were growing were put in a solution of test compound 
(concentration as shown in Table 5) for 24 hours prior to the start of the 
experiment. The effects of these treated plants to X. diversicaudatum were 
compared to that of plants whose cut ends had been immersed in water for 
24 hours. Table 5 shows that root uptake following soil application is a 
suitable method of treatment with DMDP. 
b) foliar application 
The mini-pot test and gall test described in Example 4 were repeated but 
the test compounds were administered by being painted on to the leaves of 
the tomato seedlings. In these tests, 0.4 ml test compound in solution in 
water at 200 ppm, or water alone, together with 0.05% "Tween 80" wetting 
solution, were painted onto the leaves. 
The reductions in galling of 86% in the mini-pot test and 79% in the gall 
test, over the controls, show that the effect of the test compounds was 
expressed in the root system to provide protection against nematodes. 
TABLE 5 
______________________________________ 
Activity following uptake through root - details as in text 
Mini-pot test: Petunia/Xiphinema diversicaudatum (21 days) 
% reduction in root galling 
Chemical/conc (ppm) 
relative to controls 
______________________________________ 
Oxamyl/50 92 
DMDP/15 83 
DMDP/30 100 
DMDP/100 58 
______________________________________ 
EXAMPLE 6 
Phytotoxicity Data 
DMDP was tested on three different plant species at 200 ppm for 14 days 
using methods outlined in the mini-pot test. The seedlings were then left 
to grow for 16 days and the % growth measured relative to control plants. 
Root length and shoot length were also measured. 
Table 6 shows the effect of DMDP on plant growth. All figures are % growth 
relative to controls (100%=same as control, &gt;100%=greater than control). 
Rye grass when treated with DMDP only grew to 65% of the control weight. 
This may not be significant in the field as the concentration of DMDP (200 
ppm) used was twice its effective dosage required to control nematodes. 
TABLE 6 
__________________________________________________________________________ 
Phytotoxicity data (all at 200 ppm soil water) 
Root length Shoot length 
Total weight 
Chemical 
TOM OSR 
RG TOM OSR 
RG TOM OSR 
RG 
__________________________________________________________________________ 
Oxamyl 
107 84 108 91 95 93 103 104 
107 
DMDP 90 98 105 90 97 74 100 100 
65 
__________________________________________________________________________ 
Plants 
TOM = Tomato (cv. Moneymaker) 
OSR = Oilseed rape (cv. Bienvenue) 
RG = Rye grass (cv. Melle) 
EXAMPLE 7 
Canister Test 
Small 60 ml clear canisters were filled with approximately 25 g soil. 1 ml 
test compound and 1 ml water containing 1500 PCN eggs was added. Small 
pieces of Desiree potato with sprout were placed into the compost. Lids 
pierced 3-4 times were used to close the canisters. The canisters were 
then put on a tray, covered with black polythene and Kept at a constant 
20.degree. C. After 4 weeks the first cyst count was taken, then every 
following week until the end of the eighth. Table 7 shows the % reduction 
in cysts, as compared to the control. It can be seen that DMDP was 
effective in reducing the number of cysts developing. 
TABLE 7 
______________________________________ 
Canister test (Globodera rostochiensis) 
% reduction in cysts 
Conc (ppm) 
Test Compound 
3.12 6.26 12.5 25 50 100 200 
______________________________________ 
DMDP 7 0 14 46 43 35 7 
DMDP.HCl 0 0 0 7 7 43 0 
______________________________________ 
EXAMPLE 8 
Methods of Application II 
As an extension to Example 5, further experimentation was undertaken in 
sand and soil, or a variety of plants and nematodes to demonstrate the 
different methods of applying DMDP. 
8(1) Sand Drench Test in a Tube 
Glass tubes (7.5 cm.times.2.5 cm) were filled with 24.5 g sieved dried 
sand. 4 ml nanopure water was added and a hole made in the sand. 1 ml test 
compound and 1 ml water containing 350 Meloidogyne javanica were added 
immediately before a tomato seedling was planted in the hole. All tubes 
were then left for 14 days. In this experiment and in B(2) below, 
seedlings were prepared by having their roots cut off and fine 
adventitious roots allowed to regenerate prior to use. Table 8(1) shows 
the effect of DMDP and its acid salt over a range of concentrations. 
Results are shown as % reduction in live nematodes as compared to a 
control (no test compound). 
8(2) Sand Foliar Test in a Tube 
3 glass tubes (7.5 cm.times.2.5 cm) were filled with 24.5 g sieved dried 
sand. 5 ml nanopure water was added and a tomato seedling planted in the 
tube. Non-absorbant cotton wool was inserted around the base of the 
seedling to protect the sand from the test chemical to be sprayed. The 
tubes were placed in an incubator overnight. Next day, each plant was 
sprayed with 0.1 ml test chemical from an airbrush and returned to the 
incubator. On the following day, 1 ml water containing 350 Meloidogyne 
javanica was added to each tube. All tubes were then left for 14 days. 
Table 8(2) shows the effect of DMDP and its acid salt on a range of 
plants. Results are shown in % as in Table 8(1). 
8(3) Foliar Application 
2.5 cm pots were filled with 75 g of Levington universal and sand in a 3:1 
ratio. Tomato plants (34 days old) were planted in these pots and 1 ml of 
water added. The soil was protected with filter paper and the pots left 
overnight in a glasshouse. Next day, each plant was sprayed with 0.3 ml 
test compound from an airbrush and then left in the glasshouse Overnight. 
Next day the filter paper was removed and 350 Meloidogyne javanica or 
Meloidogyne incognita in 1 ml water were added to the soil. The pots were 
then left for 12 days after which the number of live and dead nematodes 
were counted. Table 8(3) shows the effect of DMDP on a) Meloidogyne 
javanica and b) Meloidogyne incognita. 
8(4) Soil Application 
The procedure of 8(3) was repeated, except that on the first day, 1 ml test 
compound and 1 ml water with nematodes were added to the soil and the pots 
left for 14 days. Results are shown in the usual manner in Table 8(4). 
TABLE 8(1) 
______________________________________ 
Sand Drench 
% reduction in galling by M. javanica 
Conc (ppm) 
Test Compound 
200 100 50 25 10 5 1 
______________________________________ 
DMDP.HCl 47 51 30 18 43 13 
DMDP (Expt. 1) 
77 72 79 76 
DMDP (Expt. 2) 
56 57 53 56 68 63 71 
______________________________________ 
TABLE 8(2) 
______________________________________ 
Sand Foliar 
% reduction in galling by M. javanica 
Conc (ppm) 
Plant Test Compound 
3200 2400 1600 800 400 
______________________________________ 
Tomato DMDP 59 0 9 
DMDP.HCl 18 5 9 
Peppers DMDP 7 7 30 0 
DMDP.HCl 9 0 7 0 
Aubergines 
DMDP 38 43 34 9 
DMDP.HCl 44 50 19 19 
______________________________________ 
TABLE 8(3) 
__________________________________________________________________________ 
Soil Foliar % reduction in galling by a) M. javanica 
b) M. incognita 
Conc 
Test Compound 
1600 
1000 
800 
400 200 
100 50 
25 10 
1 0.1 
__________________________________________________________________________ 
a) DMDP 27 27 22 22 
a) DMDP 35 28 22 39 
34 
b) DMDP 24 24 26 
30 31 
b) DMDP 23 
22 
__________________________________________________________________________ 
TABLE 8(4) 
______________________________________ 
Soil Drench % reduction in galling by a) M. javanica 
b) M. incognita 
Conc (ppm) 
Test Compound 
100 50 20 10 1.0 0.1 0.01 
______________________________________ 
DMDP 28 19 21 
DMDP 28 30 29 20 8 
______________________________________