Pepper Rootstock Graft Compatibility and Response to Meloidogyne javanica and M. incognita.

Abstract

Resistance of pepper species (Capsicum annuum, C. baccatum, C. chinense, C. chacoense, and C. frutescens), cultivars and accessions to the root-knot nematodes Meloidogyne incognita race 2 and M. javanica, and their graft compatibility with commercial pepper varieties as rootstocks were evaluated in growth chamber and greenhouse experiments. Most of the plants tested were highly resistant to M. javanica but susceptible to M. incognita. Capsicum annuum AR-96023 and C. frutescens accessions as rootstocks showed moderate and relatively high resistance to M. incognita, respectively. In M. incognita-infested soil in a greenhouse, AR-96023 supported approximately 6-fold less nematode eggs per gram root and produced about 2-fold greater yield compared to a nongrafted commercial variety. The commercial variety grafted on AR-96023 produced a yield as great as the non-grafted variety in the root-knot nematode-free greenhouse. Some resistant varieties and accessions used as rootstocks produced lower yields (P < 0.01) than that of the non-grafted variety in the noninfested greenhouse. Use of rootstocks with nematode-resistance and graft compatibility may be effective for control of root-knot nematodes on susceptible pepper.

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Pepper Rootstock Graft Compatibility and Response to Meloidogyne
javanica and M. incognita1
Yuji Oka,2Rivka Offenbach,3and Shimon Pivonia3
Abstract: Resistance of pepper species (Capsicum annuum, C. baccatum, C. chinense, C. chacoense, and C. frutescens), cultivars and
accessions to the root-knot nematodes Meloidogyne incognita race 2 and M. javanica, and their graft compatibility with commercial
pepper varieties as rootstocks were evaluated in growth chamber and greenhouse experiments. Most of the plants tested were highly
resistant to M. javanica but susceptible to M. incognita. Capsicum annuum AR-96023 and C. frutescens accessions as rootstocks showed
moderate and relatively high resistance to M. incognita, respectively. In M. incognita-infested soil in a greenhouse, AR-96023
supported approximately 6-fold less nematode eggs per gram root and produced about 2-fold greater yield compared to a non-
grafted commercial variety. The commercial variety grafted on AR-96023 produced a yield as great as the non-grafted variety in the
root-knot nematode-free greenhouse. Some resistant varieties and accessions used as rootstocks produced lower yields (P < 0.01)
than that of the non-grafted variety in the noninfested greenhouse. Use of rootstocks with nematode-resistance and graft compat-
ibility may be effective for control of root-knot nematodes on susceptible pepper.
Key words: Capsicum spp., graft compatibility, Meloidogyne incognita, Meloidogyne javanica, nematode control, pepper, resistance,
root-knot nematodes, rootstock.
Pepper (Capsicum annuum) is one of the most impor-
tant vegetable crops in Israel. Most common pepper
varieties are susceptible to the southern root-knot
nematode Meloidogyne incognita. This nematode has
been managed with soil fumigants, mainly methyl bro-
mide. The mandated elimination of methyl bromide
will make nematode control more difficult and require
alternative control methods (Noling and Becker,
1994). Also, the trend of reduced use of nematicides
due to concerns for the environment and safe food
require environmentally friendly nematode control
methods, including use of resistant varieties. Unfortu-
nately, no pepper varieties resistant to the root-knot
nematodes are available in Israel. Grafting of suscep-
tible commercial varieties onto nematode-resistant
rootstocks is an alternative method to developing new
resistant varieties. Use of grafted vegetable plants has
not been popular in Israel, but restricted availability of
fumigant nematicides and increased interest in organic
farming likely will increase the use of grafting as a
method to manage soilborne diseases, including root-
knot nematodes. At present, grafted seedlings of to-
mato (Lycopersicon esculentum), eggplant (Solanum mel-
ongena), and watermelon (Citrullus lanatus) are com-
mercially available in Israel. Ros et al. (2002) indicated
that use of pepper rootstocks is an effective method to
control M. incognita.
In the present study, resistance of accessions of
Capsicum spp., pepper cultivars, and rootstocks to Is-
raeli populations of M. javanica and M. incognita host
race 2 was evaluated in growth chamber and green-
house studies, and their compatibility as rootstocks with
commercial pepper cultivars also was tested under
greenhouse conditions.
Materials and Methods
Nematode inoculum: Eggs of Meloidogyne incognita host
race 2 and M. javanica were extracted from pepper (C.
annuum cv. Celica) and tomato (Lycopersicon esculentum
cv. Daniela) roots, respectively (Hussey and Barker,
1973). Second-stage juveniles (J2) that emerged from
the eggs on a sieve were collected daily and stored at
15 °C. Only J2 no more than 5 days old were used in
experiments.
Pepper genotypes: The Capsicum genotypes used in the
study are listed in Table 1.
Growth chamber experiments: One-month-old seedlings
of pepper varieties Nivla, Charleston Hot, Carolina Cay-
enne, Carolina Wonder, and Charleston Belle and the
accessions, 7470 of C. baccatum, 7494 of C. chacoense,
7472 of C. chinense, and 7475 and 7493 of C. frutescens
were planted singly in 250-ml plastic pots filled with
dune sand (pH 7.8) and inoculated with 1,500 J2 of M.
incognita or M. javanica 2 days after planting. The plants
were maintained at 27 ± 2 °C in a growth chamber with
13-hour days and fertilized with 25 ml of a 0.1% solu-
tion of fertilizer (20-20-20, N-P-K) every 2 weeks. Five
weeks later, galling indexes (GI) were assessed accord-
ing to a 0-to-5 scale (0 = no infection, 1 = 1–20% of roots
galled, 2 = 21–40%, 3 = 41–60%, 4 = 61–80%, and 5 =
81–100%), and number of eggs per root system was
counted. A second experiment was conducted with cv.
Ohad and the rootstocks AR-96023, AR-96025, RS-27,
and RS-28. Plants were inoculated with 1,500 J2 of M.
javanica or M. incognita and maintained under the same
conditions as described above. In a third experiment,
Celica and the rootstocks AX 592, AX 568, EV 359,
AR-96023, AR-96025, Nun 9435, and Snooker were in-
oculated with 1,500 J2 of M. javanica or M. incognita and
Received for publication 24 July 2003.
1Supported by the Chief Scientist’s Fund of the Ministry of Agriculture and
Rural Development.
2Research Nematologist, Nematology Unit, Gilat Research Center, Agricul-
tural Research Organization, M. P. Negev 85280, Israel.
3Extension Agronomist and Research Plant Pathologist, Arava Research and
Development, Yair Experiment Station, M. P. Arava 86825, Israel.
The authors thank M. Di Vito and R. L. Fery for reviewing the manuscript, N.
Tkachi and S. Shuker for dedicated technical assistance, and R. L. Fery, A. Levi,
and the seed companies for supplying seeds.
E-mail: okayuji@volcani.agri.gov.il
This paper was edited by P. A. Roberts.
Journal of Nematology 36(2):137–141. 2004.
© The Society of Nematologists 2004.
137

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maintained under the same conditions described
above. All experiments were performed with 5 replica-
tions/genotype and nematode species.
Greenhouse resistance experiments: Grafted seedlings
were prepared with Charleston Hot, Carolina Cayenne,
AR-96023, AR-96025, RS-27, RS-28, and RS-50 as root-
stocks and cv. Celica as the scion by tube grafting (Lee
and Oda, 2003). Ungrafted Celica seedlings served as
controls. The grafted and non-grafted seedlings were
planted in sandy soil (pH 7.4) in a greenhouse ground
bed infested with M. incognita host race 2. Mean pre-
plant nematode density in the top 20 cm of soil, esti-
mated from 32 samples each consisting of three sub-
samples of 200 cm3soil, was 13.5 ± 15.8 J2/50 g. The
planting area was divided into 32 plots of 2.25 m2(1.5
× 1.5 m) arranged in a randomized complete block
design with four replicates. Eight plants were planted
on 13 September 2001 in each plot. Galling index (0–5)
and number of nematode eggs per g roots were re-
corded 42 days after planting. In the second experi-
ment, conducted the following year, seedlings of non-
grafted and grafted Celica on AR-96023 and Snooker
were planted on 4 September 2002 in the same green-
house. The experimental unit was 20 plants in two lines
on a bed of 4.0 × 1.5 m with four replicates. Mean
pre-plant nematode density in the top 20 cm of soil,
estimated from 12 samples each consisting of four sub-
samples of 200 cm3soil, was 17.7 ± 24.5 J2/50 g. Stan-
dard drip-irrigation, fertilization, insect disease, and fo-
liar disease control methods for pepper in the region
were performed. The plants were harvested from 25
December 2002 to 2 April 2003, and GI (0-10) and
number of nematode eggs per g roots were recorded at
the end of the experiment (Bridge and Page, 1980).
Greenhouse compatibility experiments: Seedlings of non-
grafted and grafted Celica on rootstocks AR-96023, AR-
96025, RS-27, RS-28, RS-29, and RS-50 and on cultivars
Charleston Hot, Carolina Cayenne, Carolina Wonder,
and Charleston Belle were planted in a non-infested
greenhouse on 5 September 2001. The soil was treated
with methyl bromide (600 kg/ha) 21 days before plant-
ing to control fungal diseases and weeds. The experi-
mental unit was 20 plants in two lines on a bed of 4.0 ×
1.5 m with two replicates, where means and SD of yield
were calculated. The pepper plants were harvested
from 9 December 2001 to 19 May 2002. In the second
experiment, conducted the following year, seedlings of
non-grafted and grafted Celica on Snooker, RA-96023,
C. chacoense accession 7494, and C. frutescens accessions
7475 and 7493 as well as seedlings of non-grafted and
grafted Parker on AR-96023 were planted on 4 Septem-
ber 2002 in another non-infested greenhouse 21 days
after treatment with methyl bromide (600 kg/ha). The
experimental unit was 20 plants in two lines on a bed of
4.0 × 1.5 m with four replicates. Pepper plants were
harvested from 18 December 2002 to 12 May 2003.
Standard drip irrigation, fertilization, insect disease,
and foliar disease control methods for pepper in the
region were performed in the two experiments.
Data analysis: Data were subjected to analysis of vari-
TABLE 1. Capsicum genotypes tested for resistance to Meloidogyne incognita and M. javanica.
Capsicum speciesGenotypeUsea
Host
statusb
Origin
C. baccatum
C. chacoense
C. chinense
C. frutescens
C. frutescens
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
C. annuum
Capsicum sp.
7470
7494
7472
7475
7493
Charleston Hot
Carolina Cayenne
Carolina Wonder
Charleston Belle
Celica
Nivla
Parker
Ohad
AR96023
AR96025
RS-27
RS-28
RS-29
RS-50
AX 592
AX568
EV 359
Snooker
Nun9453
A. Levi, Bet-Dagan, Israel
A. Levi, Bet-Dagan, Israel
A. Levi, Bet-Dagan, Israel
A. Levi, Bet-Dagan, Israel
A. Levi, Bet-Dagan, Israel
R. L. Fery, USDA, Charleston, SC, USA
R. L. Fery, USDA, Charleston, SC, USA
R. L. Fery, USDA, Charleston, SC, USA
R. L. Fery, USDA, Charleston, SC, USA
Enza Zaden, Enkhuizen, Netherlands
De Ruiter Seeds, Bergschenhoek, Netherlands
De Ruiter Seeds, Bergschenhoek, Netherlands
Hazera, Brurim, Israel
Milchan Bros., Ramat-Gan Israel
Milchan Bros., Ramat-Gan Israel
Milchan Bros., Ramat-Gan Israel
Milchan Bros., Ramat-Gan Israel
Milchan Bros., Ramat-Gan Israel
Milchan Bros., Ramat-Gan Israel
Tarsis, Beer-Sheva, Israel
Tarsis, Beer-Sheva, Israel
Nirit Seeds, Hadar, Israel
Syngenta Seeds, Westeinde, Netherlands
Nunhems Zaden, Haelen, Netherlands
F
F
F
F
F
F
F
F
R
R
R
R
S
S
S
S
RS
RS
RS
RS
RS
RS
RS
RS
RS
RS
RS
T
T
T/R
R
aCommercial use: fruit production (F), rootstock (RS).
bHost status indicated by the supplier: resistant (R), tolerant (T), susceptible (S).
138 Journal of Nematology, Volume 36, No. 2, June 2004

Page 3

ance, and means were separated according to Tukey-
Kramer HSD test (? = 0.05). All calculations were per-
formed with JMP (SAS Institute, Cary, NC).
Results
Growth chamber experiments: The GI and number of M.
javanica eggs on most of the accessions, pepper culti-
vars, and rootstocks were low in experiment 1, except
the numbers of eggs on Nivla, C. chinense 7472, and C.
chacoense 7494 (Table 2). Among the plants inoculated
with M. incognita, Carolina Cayenne and the C. frutescens
accessions had lower GI and numbers of eggs than
those of the control Nivla (Table 2). The nematode-
resistant cultivars Charleston Belle and Carolina Won-
der were susceptible to the M. incognita race 2 isolate.
Among the rootstocks tested in experiments 2 and 3,
only AR-96023 had lower GI (P < 0.001) and numbers
of M. incognita eggs (P < 0.01) on the roots than those
of the susceptible cultivars (Table 2). The rootstock
Snooker had intermediate resistance to M. incognita.
On some rootstocks in experiment 3, M. javanica re-
produced at low levels (Table 2).
Greenhouse resistance experiments: In the M. incognita-
infested greenhouse, the rootstock AR-96023 and
Charleston Hot and Charleston Cayenne had lower GI
(P < 0.001) and numbers of nematode eggs (P < 0.01)
than those of the susceptible control Celica in the first
experiment (Table 3). In the second experiment, the
rootstock AR-96023 had lower GI than the susceptible
cultivars (P < 0.001) (Table 4). The yield of Celica
grafted on AR-96023 was more than 2-fold that of non-
grafted Celica (Table 4). The rootstock Snooker, which
was heavily galled, did not increase the yield of the
cultivar, though the number of nematode eggs was
lower (P = 0.03) than that on Celica roots (Table 4).
Greenhouse compatibility experiments: In the non-
infested greenhouse, yields of Celica grafted on the
rootstocks were the same or slightly lower than that of
the non-grafted Celica plants in the first experiment
(Table 3). In contrast, the yield of Celica grafted on
Charleston Hot or Charleston Belle was lower than that
of the non-grafted plants. In the second experiment,
Celica grafted on the rootstock AR-96023 had similar
yield to the non-grafted Celica, but the yield and per-
centage of exportation grade fruit of Parker grafted on
the rootstock were lower (P = 0.005) than those of non-
grafted Parker (Table 4). The yield and percentage of
exportation grade fruit of Celica grafted on the acces-
TABLE 2.
system on pepper genotypes inoculated with Meloidogyne javanica or
M. incognita in pots in a growth chamber.
Root galling index (GI) and number of eggs per root
Pepper genotypes
M. javanicaM. incognita
GI (0–5)
Eggs/root
systema
GI (0–5)
Eggs/root
systema
Experiment 1
C. annuum cultivar
Nivla
Carolina Wonder
Charleston Belle
Carolina Cayenne
C. frutescens accession
7475
7493
C. chinense
7472
C. chacoense
7494
C. baccatum
7470
1.3 a
0 b
0 b
0 b
19,650 a3.7 a
2.5 bc
2.8 abc
0.8 d
104,625 a
74,813 ab
90,000 a
33,188 b
0 b
0 b
0 b
0 b
0 b
0 b
0 b
0.3 d
1.4 d
8,265 bc
4,125 c
0.8 a 24,563 a 2.1 c62,813 ab
0.9 a 16,219 a0.4 d 16,875 abc
0 b 0 b
Experiment 2
3.2 ab87,000 a
C. annuum cultivar
Ohad
C. annuum rootstock
AR-96023
AR-96025
RS-27
RS-28
0.5 a 16,867 a2.5 a 109,710 a
0 b
0 b
n.t.b
0 b
0 b
0 b
n.t.
0 b
Experiment 3
0.8 c
2.0 ab
1.8 b
1.7 b
38,563 b
108,790 a
68,157 a
84,103 a
C. annuum cultivar
Celica
Capsicum rootstock
AX 592
AX 568
AR-96023
AR-96025
EV 359
Snooker
Nun 9453
0.7 ab 9,500 a3.3 ab 112,800 ab
1.0 a
0 c
0 c
0 c
0.5 abc
0.3 bc
0 c
18,750 a3.2 ab
2.9 b
0.8 c
2.9 b
3.0 b
1.3 c
3.3 ab
139,600 a
146,600 a
43,800 c
127,875 ab
133,800 ab
85,200 bc
139,250 ab
0 c
0 c
0 c
6,000 a
1,625 b
0 c
Data are means of five replicates. Means within a column followed by the
same letter in each experiment are not different according to Tukey-Kramer
HSD test (? = 0.05).
aStatistical analysis of eggs/root system data was done after log10(x + 1)
transformation.
bn.t. = not tested.
TABLE 3.
of root on non-grafted and grafted pepper cultivars and rootstocks
grown in a greenhouse infested with Meloidogyne incognita, and yield
in uninfested soil.
Root galling index (GI) and number of eggs per gram
Cultivar and rootstock
Infested soila
Fruit yield in
uninfested soilc
Total (kg)d
Exp.
(%)c
GI (0–5)Eggs/g rootsb
Non-grafted cv. Celica
Grafted cv. Celica on
AR-96023
AR-96025
RS-27
RS-28
RS-29
RS-50
Charleston Hot
Charleston Belle
Charleston Cayenne
Charleston Wonder
4.7 a 29,947 a 72.3 ± 3.574.5
0.7 c
4.8 a
3.8 ab
3.1 b
4.0 ab
4.7 a
0.2 c
4.4 a
0.7 c
n.t.f
4,117 b
29,002 a
27,506 a
10,192 ab
18,168 ab
24,570 a
1,800 b
20,193 ab
2,295 b
n.t.
75.0 ± 0.7
72.1 ± 3.8
61.9 ± 38.3
68.2 ± 2.1
69.3 ± 1.7
66.3 ± 2.8
47.9 ± 0.4
47.4 ± 13.0
59.5 ± 11.6
65.0 ± 0.4
73.0
76.0
76.0
73.0
75.5
71.0
63.5
71.0
69.5
71.5
aData are means of four replicates. Means within a column followed by the
same letter are not different according to Tukey-Kramer HSD test (? = 0.05).
bStatistical analysis of eggs/g root data was done after log10(x + 1) trans-
formation of six replicates.
cData are means and SD of two replicates.
dMeans ± SD of two experimental units, each containing 20 plants.
ePercentages of exportation grade fruit.
fn.t. = not tested.
Pepper Rootstock Response to Meloidogyne spp: Oka et al. 139

Page 4

sion 7475 of C. frutescens were lower (P < 0.001) than
that of non-grafted Celica plants. No root galls were
found on ungrafted Celica roots at the end of the two
experiments.
Discussion
Use of resistant rootstocks is an effective control
method for plant-parasitic nematodes. Fruit trees such
as Prunus spp., Citrus spp., Vitis spp. are usually grafted
onto rootstocks possessing resistance to soilborne
pathogens and pests, including nematodes. Rootstocks
are also used to improve plant growth. Use of grafted
vegetable seedlings, especially watermelon, melon, cu-
cumber, tomato, and eggplant, has been popular in
some countries, such as Japan (Lee and Oda, 2003).
Withdrawal of effective nematicides and adverse effects
of the use of pesticides have promoted development
and use of rootstocks in vegetable crops. In the present
study, Capsicum spp. accessions, rootstocks, and culti-
vars were tested for resistance to M. incognita and M.
javanica as well as their graft compatibility to commer-
cial pepper cultivars. All the plants tested in the experi-
ments were highly to moderately resistant to M. ja-
vanica. Carolina Wonder and Charleston Belle, which
have been reported to be resistant to M. incognita race
3 (Fery et al., 1998), were not resistant to race 2 of the
nematode in our study. The difference in our results
from those reported by other authors may be due to the
nematode races and populations, and also the tempera-
ture in our study. The accessions of C. frutescens were
highly resistant to both M. javanica and M. incognita.
The accession of C. chacoense was also resistant to M.
incognita, but it was not immune to M. javanica. Several
accessions of Capsicum spp. have been tested for resis-
tance to four Meloidogyne species, and different levels of
resistance to the nematodes were found (Di Vito et al.,
1991). Resistance of C. chinense lines has also been re-
ported (Fery and Thies, 1997; Thies and Fery, 2000).
The rootstock AR-96023, the lines of C. frutescens, and
hot pepper cv. Charleston Hot and Carolina Cayenne
showed resistance to M. incognita in both growth cham-
ber and greenhouse experiments.
Soil temperature may be an important factor for
nematode resistance in pepper plants, similar to resis-
tance to Meloidogyne species in tomato based on the Mi
gene (Holtzmann, 1965). The resistance to M. incognita
of one line each of C. annuum, C. chacoense and C. fru-
tescens and three lines of C. chinense was reported to be
stable at a soil temperature of 38 °C (Di Vito et al.,
1995), but in other reports the resistance was broken by
temperatures higher than 32 °C (Thies and Fery, 1998,
2000). In our greenhouse experiments, soil tempera-
ture (10-cm depth) rose above 32 °C early in the grow-
ing season; however, AR-96023 roots had far fewer galls
than the susceptible cultivar and the rootstock
Snooker. This result suggested that AR-96023 is likely to
be a heat-stable resistant rootstock. Use of resistant
rootstocks, in addition to reduction of plant damage
caused by nematodes, may reduce nematode popula-
tions in soil and may serve as a rotation crop (Thies et
al., 1998; Thies and Fery, 2002). However, increased
nematode incidence and population aggressiveness
were reported after using the same rootstocks in the
same soil (Ros et al., 2002).
Another important feature of rootstocks is their com-
patibility with commercial varieties used as scions. An
incompatible rootstock may result in a lower yield of a
scion cultivar than that of the ungrafted cultivar even in
TABLE 4.
in a greenhouse infested with Meloidogyne incognita, and fruit yield of the non-grafted and grafted cultivars on the rootstocks grown in
uninfested soil.
Root galling index (GI) and number of eggs per gram of root on pepper cultivars and grafted rootstocks and accessions grown
Cultivar, rootstock, and accession
Infested soil
GI (0–10)a
Eggs/g rootsb
Fruit yieldc
Fruit yield in uninfested soilc
Total (kg)Exp. (%)d
Total (kg)Exp. (%)d
Parker
Non-grafted
Grafted on AR-96023
Celica
Non-grafted
Grafted on
AR-96023
Snooker
C. chacoense 7494
C. frutescens 7475
C. frutescens 7493
n.t.e
n.t.
n.t.
n.t.
n.t.
n.t.
n.t.
n.t.
54.4 a
47.9 b
65.3 a
50.0 b
7.8 a 46,800 a 20.2 b29.3 ab70.3 a 63.8 a
0.7 b
6.5 a
n.t.
n.t.
n.t.
8,343 c
29,400 b
n.t.
n.t.
n.t.
43.8 a
26.8 b
n.t.
n.t.
n.t.
37.3 a
15.3 b
n.t.
n.t.
n.t.
68.6 a
53.0 a
44.8 a
6.3 b
49.4 a
53.5 ab
57.0 ab
53.5 ab
25.0 b
44.0 ab
aData are means of four experimental units containing 20 plants each. Means within a column followed by the same letter in each cultivar are not different
according to Tukey-Kramer HSD test (? = 0.05).
bStatistical analysis was done after log10(x + 1) transformation of four replicates.
cMeans of four experimental units, each containing 20 plants.
dPercentages of exportation grade fruit.
en.t. = not tested.
140 Journal of Nematology, Volume 36, No. 2, June 2004

Page 5

the absence of nematodes. The accessions of C.
chacoense and C. frutescens and Charleston Hot and Caro-
lina Cayenne showed high resistance to M. incognita;
however, the cultivar Celica grafted on most of these
rootstocks gave lower yields than that of the ungrafted
cultivar in non-infested greenhouse experiments. Graft-
ing of two Capsicum spp. may not always result in low
compatibility. Grafting between different species (inter-
specific) and even genera (inter-generic) is well ac-
cepted in vegetable crops grown from grafted seedlings
(Lee and Oda, 2003).
A problem of using grafted seedlings is their rela-
tively high cost, although their use would offset the cost
for pest management, particularly that of soil disinfes-
tations. Cost of a grafted vegetable seedling is as much
as 5-fold higher than that of a non-grafted seedling in
Israel. Development of improved grafting technology
and horticultural practices in the future may reduce the
cost of the seedlings and the number of plants per area.
The results of the present study suggest that use of
nematode-resistant pepper rootstocks can be an effec-
tive control method, especially when nematode-
resistant cultivars are not available or nematicides can-
not be used, such as in organic farming systems. Root-
stocks possessing resistance to M. incognita races and
good graft compatibility with commercial varieties can
be developed by careful selection for the resistance and
compatibility.
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Capsicum spp. to Italian populations of four species of Meloidogyne.
Nematologia Mediterranea 19:43–46.
Di Vito, M., G. Zacheo, F. Catalano, and G. Oreste. 1995. Effect of
temperature on stability of resistance to root-knot nematode (Meloido-
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