Les effets d'extraits commerciaux de l'algue marine #Ascophyllum nodosum$ sur la fécondité du nématode #Meloidogyne javanica$, élevé sur tomate (#Lycopersicon esculentum$ cv. Ailsa Craig) sont évalués. Après une génération, le nombre d'oeufs du nématode récupérés sur les plantes traitées diminue considérablement en comparaison avec les plantes témoins, traitées avec de l'eau pure. Un plus faible nombre d'oeufs sont récupérés sur les plantes infestées par des juvéniles ayant incubé dans des extraits d'algue en comparaison avec les plantes infestées par des juvéniles ayant incubé dans de l'eau pure. (Résumé d'auteur

Blunden, G.

Hankins, S.D.

Jenkins, T.

Whapham, C.A.

Horizon / Pleins textes

Fundam. appl. NemalOl., 1994,17 (2), 181-183
The role of seaweed extracts, Ascophyllum nodosum,
in the reduction in fecundity of Meloidogyne javanica
Catherine A. WHAPHAM*, TeifrynJENKlNS**, Gerald BLUNDEN* and Simon D. HANKlNS***
* School ofPharmacy & Biomedical Sciences, Park Building
** School ofBiological Sciences, King Henr)' Building,
University ofPortsmouth, King Henr)' I Streeet,
Portsmouth, Hampshire, POl 2DZ, u.K., and
*** Maxicrop Intemational Ltd, Weldon Rnad, Corby, NOTthamptonshire, NN17 1US, U. K
Accepted for publication 26 July 1993.
Summary - The effects are evaluated of commercially-available seaweed extracts, derived from Ascophyllum nodosum, on me
fecundiry ofme root-knot nematode, Meloidogynejavanica, cultured on tomato plants (Lycopersicon esculenlum cv. Ailsa Craig). The
numbers of nematode eggs recovered from plants treated wim seaweed extract were significanùy reduced after one generation,
compared to mose plants treated wim water alone. Fewer eggs were recovered from plants infected by juveniles hatched in dilutions
of me seaweed extracts compared wim mose infected by water-hatched juveniles.
Résumé - Effets des extraits d'une algue marine sur la diminution ckfécondiu de Meloidogyne javanica - Les effets
d'extraits commerciaux de l'algue marine Ascophyllum nodosum sur la fécondité du nématode Meloidogyne javanica, élevé sur tomate
(Lycopersicon esculemum cv. Ailsa Craig) sont évalués. Après une génération, le nombre d'œufs du nématode récupérés sur les
plantes traitées diminue considérablement en comparaison avec les plantes témoins, traitées avec de l'eau pure. Un plus faible
nombre d'œufs sont récupérés sur les plantes infestées par des juvéniles ayant incubé dans des extraits d'algue en comparaison avec
les plantes infestées par des juvéniles ayant incubé dans de l'eau pure.
Key-words : Ascophyllum nodosum, biological control, Meloidogyne, seaweed extract.
Non-pesticide control is being regarded favourably in
agriculture as envirorunental awareness increases. Orga-
nie amendments, such as composted leaf mould (Miller,
1977) and chitin (Godoy el al., 1983) have been sug-
gested as possible alternative methods of nematode
management.
Claims have been made in recent publications that the
application of seaweed extracts to plants has resulted in
a decreased incidence of pathogen attack. In 1977, Tar-
jan recorded that when Ascophyllum nodosum kelp ex-
tract was applied to citrus seedlings infected with Ra-
dopholus similis these seedlings weighed more, and had
fewer nematodes, than the water control seedlings.
Maxicrop and Sea-Born liquid kelp (A. nodosum) prep-
arations effectively controlled sting nematodes (Belono-
laimus longicaudalUS) on centipede grass one month after
application (Morgan & Tarjan, 1980). Featonby-Srnith
and Van Staden (1983) found that root-knot nematode
infestation in tomato plants was visibly reduced in ail
cases when a seaweed concentrate prepared from Ecklo-
nia maxima was applied as a soil drench. A similar effect
was discovered by Paracer el al. (1987) when soil
amendments of SpaLOglossum schroderi significantly re-
duced root galling of tomato plants infected with Me-
loidogyne incognita, M. arenaria and M. javanica. Sea-
/SSN 1164-5571194/02 S 4.00/ © Gauthier-Villars - ORSTOM
weed concentrate prepared from E. maxima,
significant1y suppressed the reproduction of Pralylen-
chus zeae on excised maize roots (De Waele et al., 1988).
More recently, Crouch and Van Staden (1993) rec-
orded significant increases in plant growth and reduced
infestation by M. incognita when seaweed concentrate,
prepared from E. maxima, was applied as a soil drench.
In this study the potential role of extracts of the brown
alga, Aswphyllum nodosum, in the control of the root-
knot nematode, M.javanica, was investigated. Particular
emphasis was given to their effects on the motility of the
juvenile stages and the fecundity of the adult female.
Materials and methods
SEAWEED EXTRACTS
The brown marine alga, A. nodosum, provides the
basis for the commercially-available seaweed ex tracts
marketed by Maxicrop International Ltd. These aque-
ous a1kaline extracts are formulated as Maxicrop Origi-
nal, Maxicrop Triple and Maxicrop Concentrate, which
contain approximately 8 %, 16 % and 24 % w/v seaweed
solids, respectively. Maxicrop Triple also contains add-
ed trace elements, magnesium, iron, boron, zinc and
copper being the main components.
181
C. A. Whapham et al.
TEST NEMATODE
Meloidogyne javanica was obtained from stock cul-
tures maintained on tomato plants cv. Ailsa Craig. The
enrire root baU with soil was immersed in water and the
soil removed genùy, without dislodging any egg sacs.
Eggs were extracted by vigorous shaking of infested
roots in a 1 % sodium hypocWorite solution for three
minutes. The resulting suspension was then passed
through a range of different mesh sieves (Hussey &
Barker, 1973). Eggs were fmaUy collected on a fine sieve
(38 /-Lm) and washed with several changes of tap water
to remove ail traces of sodium hypocWorite.
HATCH1NG
The recovered eggs were hatched over a period of
7 days in beakers containing either water, as a control, or
seaweed extract at a concentration of 3.6 % Maxicrop
Original or 1.8 % Maxicrop Triple or 1.2 % Maxicrop
Concentrate, which are dilutions recommended by the
manufacturers for horticultural use. The eggs were aer-
ated and left to hatch at room temperature (approxi-
mately 20 OC).
INOCULATION AND TREATMENT
A sample of 70 tomato plants, aU at the four-leaf stage
and planted in 450 cm3 (approximately) of John Innes
No. 1 soil, was divided into seven experimentaJ sets to
give ten plants per set. Two plastic, perforated pipette
tips were placed either side of the stem of each plant and
pushed into the soil to a depth of approximately 2 cm.
The infective dose, comprising 600 second stage juve-
niles Q2) of M. javanica per plant, was inoculated
through these pipettes. Forty plants received J2 which
had been hatched in tap water (water-hatched), and
batches of ten plants received J2 hatched in 3.6 % Max-
icrop Original, 1.8 % Maxicrop Triple or 1.2 % Max-
icrop Concentrate (treatrnent-hatched).
Each set of plants then received 50 ml per plant of one
of four treatrnents, applied as a root drench on a weekly
basis. A sampie of ten plants, infected with water-
hatched J2 was treated with water, and so represented
the control treatrnent. Twenty plants, ten infected with
water-hatched J2 and ten infected with juveniles which
had been hatched in 3.6 % Maxicrop Original, were
treated with 3.6 % Maxicrop Original. Twenty plants,
ten infected with water-hatched J2 and ten infected with
juveniles which had been hatched in 1.8 % Maxicrop
Triple, were treated with 1.8 % Maxicrop Triple. The
final 20 plants, ten infected with water-hatched J2 and
ten infected with juveniles which had been hatched in
1.2 % Maxicrop Concentrate, were treated with 1.2 %
Maxicrop Concentrate. The plants were maintained in
glasshouse conditions at 20 oC ± 4 oC for 45 days post-
inoculation.
The egg sacs from each plant in each experimental set
were removed using 1 % sodium hypocholorite and the
182
total numbers of eggs recovered from the sacs were
counted.
ACTIVITY ASSESSMENT
M. javanica eggs were hatched in either water or 1 %
Maxicrop Original. Activity 0[]2 in water and 1 % Max-
icrop Original was assessed using the method of Evans
and Wright (1982). Briefly, 200 viable J2 were placed
on the top of a sand colurtlll (height 2 cm) sand particle
size 250-600 /-Lm; Sigma) in a polythene tube
(3 x 0.5 cm» with nylon mesh (200 /-Lm aperture) cov-
ering the bottom end. Tubes were placed upright in a
specimen tube containing 5 ml test solution (either wa-
ter or 1 % Maxicrop Original). After 24 hours at 20 oC
the number of juveniles that had migrated through the
mesh into the outer solution was recorded.
Both methods have been sub;ected ta repetition and
consistent results have been recorded throughout the
investigations. Means and standard error of the means
are shown in the results section, using T-test compari-
sons for significance.
Results
The mean numbers of Meloidogyne javanica eggs re-
covered from each set of ten tomato plants are summar-
ised in Figure 1. There was a significant reduction in egg
recovery from plants receiving the seaweed treatrnents
compared to the water-treated controls (Fig. 1). This
difference was significant at the 5 % level for each of the
three seaweed treatrnents. AdditionaUy, there were sig-
nificanùy fewer eggs recovered from plants which had
been inoculated with J2 hatched in seaweed solutions
compared with plants inoculated with J2 that had been
water hatched (Fig. 1). This difference was sigillficant at
the 5 % level for aU three seaweed treatrnents. ln the
most extreme case, treatrnent of tomato plants with
Maxicrop Original after infection with treatrnent-
hatched J2, reduced the number of eggs produced after
one generation 18 fold when compared to the water-
treated tomato plants infected with water-hatched J2
(Fig. 1). This is a reduction of over 94 %. Maxicrop
Concentra te treated tomate plants infected with water-
hatched J2 showed a 1.5 fold reduction when compared
to the water control, a reduction of 34.9 %.
The numbers of eggs recovered from plants which
had received water-hatched J2, and which had also re-
ceived the Maxicrop treatrnents were significanùy re-
duced compared with those infected plants receiving
water treatrnents alone (Fig. 1). This difference was
significant at the 5 % level and had an average reduction
of 42.7 %.
The effect of seaweed extracts on nematode activity
was investigated using sand colurtllls and the results
demonstrate that the hatching of J2 in 1 % Maxicrop
Original had a more dramatic effect on sand colurnn
migration (95 % reduction) than an environment in
which the sand was soaked in 1 % Maxicrop Original
(50 % reduction) (Table 1). However, both variables
Fundam. appl. Nemawl.
Roie of seaweed eXlraCIS on Meloidogyne javanica
Trealmenl
Table 1. The mean percenlage (± standard error oflhe mean) ofJ2
ofMeloidogyne javanica recu:hing lhe ouler solution afier passage
lhrough sand columns (n = 5), based on an initial dose applicalion
of200J2.
Discussion
This work shows that soil drench application of sea-
weed extracts derived from Ascophyllum nodosum re-
duced Meloidogyne javanica infestation of tomato plants
compared to untreated controls. This reduction was
even greater when the infective stage juveniles used as
the inoculum had been hatched directly into the seaweed
solutions. Plants that received water-hatched juveniles,
and which were then treated weekly with seaweed ex-
tracts, also showed a significant reduction in the num-
bers of eggs recovered after one generation when com-
pared with infected plants treated with water alone.
By treatrnent-hatching of the eggs, any effect of the
treatments wouId be registered early on in the infective
J2 stage. Inoculation with treatrnent-hatched juveniles
produced significantly lower numbers of recovered eggs
than when water-hatched juveniles were used. The ac-
tivity tests support the view that reduced mobility is at
least partly responsible for low levels of penetration
which consequently affects egg number at the comple-
tion of the life cycle. Juveniles appeared viable when first
placed on the sand columns but very low numbers rni-
grated to the outer solutions after hatching in a seaweed
environment.
Further studies are aimed at the determination of the
compounds present in the seaweed extracts responsible
for reducing the level of nematode populations.
References
CROUCH, 1.]. & VAN STADEN,]. (1993). Effect of seaweed
concentrate from Ecklonia maxima (Osbeck) Papenfuss on
Meloidogyne incognita infestation on tomato J. appl. Phycol.,
5: 37-43.
DE WAELE, D., McDoNALD, A. H. & DE WAELE, E. (1988).
Influence of seaweed concentrate on the reproduction of
Pralyienchus zeae (Nematoda) on maize. Nemawlogica, 34 :
71-77.
EVANS, S. G. & WRIGHT, D.]. (1982). Effects of the nemat-
icide oxamyl on the life cycle stages of Gwbodera roslOchien-
sis. Ann. appl. Biol., 100: 511-519.
FEATONBY-SMJTH, B. C. & VAN STADEN, J. (1983). The
effect of seaweed concentrate on the growth of tomato
plants in nematode infested soil. Scienlia Hortie., 20: 137-
146.
GODOY, G. RODRIQUEZ-KABANA, R. SHELBY, R. A. & MOR-
GAN-JONES, G. (1983). Chitin amendments for control of
Meloidogyne arenaria in infested soil. II - Effects on micro-
bial population. Nernalropica, 13 : 63-74.
HUSSEY, R. S. & BARKER, K. R. (1973). A comparison of
methods of collecting inocula for Mewidogyne spp., includ-
ing a new technique. Pl. Dis. Replr, 57: 1025-1028.
MILLER, P. M. (1977). Reducing field populations of severa!
plant parasitic nematodes by leaf mould composts and sorne
other additives. Pl. Dis. Replr, 61 : 328-331.
MORGAN, K. T. & TARJAN, A. C. (1980). Management of
sting nematode on centipede grass with kelp extraets. Proc.
Ft. SI. hortic. Soc., 93 : 97-99.
PARACER, S., TARJAN, A. c., HODGSON, L. M. (1987). Ef-
fective use of marine algal products in the management of
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T ARJAN, A. C. (1977). Kelp derivatives for nematode infected
citrus trees. J. Nemawl., 9 : 287.
32%±5 %
1.8 %± 1 %
1 % Maxicrop
Origina! soaked
Colurnn
Water soaked
sand
Column
3.0 %±0.9 %
66.3 %± 6.7 %
Treatments
Water-Hatched
Juveniles
Treatment-Hatched
Juveniles
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35
produced a significant decrease in the numbers of ne-
matodes reaching the outer solution. The nematodes
hatched in 1 % Maxicrop Original solution appeared to
be viable through movement seen with the use of micro-
scope.
Fig. 1. The mean [± standard e1TOT (SEM)} number of eggs of
Meloidogyne javanica per 10malO plant (n = 10) afier lrealmenl
for 45d with water (W), Maxicrop original (MO), Maxicrop Triple
(MT) and Maxicrop Concentrale (MC). Plants had originally
been inoculated with J2s which had haLChed in élher waler ( ) or
lhe lrealment Solulion (0).
Vol. 17, n° 2 - 1994 183


The role of seaweed extracts, Ascophyllum nodosum, in the reduction in fecundity of Meloidogyne javanica

Les effets d'extraits commerciaux de l'algue marine #Ascophyllum nodosum$ sur la fécondité du nématode #Meloidogyne javanica$, élevé sur tomate (#Lycopersicon esculentum$ cv. Ailsa Craig) sont évalués. Après une génération, le nombre d'oeufs du  nématode récupérés sur les plantes traitées diminue considérablement en comparaison avec les plantes témoins, traitées avec de l'eau pure. Un plus faible nombre d'oeufs sont récupérés sur les plantes infestées par des juvéniles ayant incubé dans des extraits d'algue en comparaison avec les plantes infestées par des juvéniles ayant incubé dans de l'eau pure. (Résumé d'auteur

The role of seaweed extracts, Ascophyllum nodosum, in the reduction in fecundity of Meloidogyne javanica

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