Page 21 - Volume 6, Issue 1, January 2013
Basic HTML Version
© Benaki Phytopathological Institute
1
Plant Protection and IPM Department, Faculty of Ag-
riculture,
2
Plant Production Dept., Faculty of Agriculture, Mutah
University, Karak P.O. Box 7, 61710 Jordan
*
Corresponding author:
Hellenic Plant Protection Journal
6:
19-27, 2013
Ability of nitrogen containing salts to control the root-knot
nematode (
Meloidogyne javanica
) on tomato
M.R. Karajeh
1*
and F.M. Al-Nasir
2
Summary
The influence of different nitrogen containing salts and sodium chloride at gradual elec-
trical conductivity levels (ECs 2, 4, 6 and 8 mS/ cm) on the root-knot nematode (
Meloidogyne javanica
)
and their interaction with tomato was evaluated under growth chamber and greenhouse conditions.
Both ammonium chloride (NH
4
Cl) and ammonium sulfate ((NH
4
)
2
SO
4
) were more effective than ammo-
nium nitrate (NH
4
NO
3
) which was more effective than potassium nitrate (KNO
3
) and sodium chloride
(NaCl) in suppressing
M. javanica
by reducing root galling and nematode reproduction on tomato cv.
GS12. Under greenhouse conditions, the minimum significant galling index values assessed for NH
4
Cl,
(NH
4
)
2
SO
4
, NH
4
NO
3
and KNO
3
were 1.60, 2.04, 2.30 and 3.30, respectively whereas the maximum value
(4.01) corresponded to NaCl and was not statistically different from the control (4.92). A significant in-
crease in tomato growth and protein content for (NH
4
)
2
SO
4
and NH
4
NO
3
was observed. On the other
hand, in NaCl treatment, there was a decrease in dry weights and protein content due to salinity com-
pared with the control. The higher salt ECs did not affect the pH of the rhizospheric soil but slightly in-
creased its measured EC and salinity. Hence, (NH
4
)
2
SO
4
is a more suitable candidate than NH
4
Cl for the
effective control of the root-knot nematode when irrigation water is a limiting factor with high salinity
level similar to NaCl. Therefore, the use of ammonium containing salts especially (NH
4
)
2
SO
4
and NH
4
Cl
alone or in combination with other control measures may result in controlling
M. javanica
.
Additional keywords
: fertilizers, management,
Solanum lycopersicum
, suppression
Introduction
Root-knot nematodes (
Meloidogyne
Goldi
1892 - RKN) are obligate parasites of high-
er plants distributed worldwide and consid-
ered major nematode pests, causing great
crop losses annually (Sasser, 1987; Sasser
and Freckman, 1987; Nickle, 1991) and re-
duction of product quality on almost every
plant species (Anastasiadis
et al
., 2011).
Tenuta and Ferris (2004) reported that
Meloidogyne javanica
(Treub) Chitw.
reared
on solid medium and in hydroponic cul-
ture, were slightly more sensitive to specific
ion and osmotic effects than nematodes of
similar colonizer-persister groups obtained
from soil. Also, gradients of salts of the spe-
cific ion repellents (NH
4
+
, K
+
, Cl
-
, and NO
3
-
) for
M. incognita
have been demonstrated to
shield tomato (
Solanum lycopersicum
Mill.)
roots from root knot nematode infection
in soil (Marks and Sayre, 1964; Edongali and
Ferris, 1982; Ismail and Saxena, 1977; Castro
et al
., 1991), furthermore, NH
4
+
, K
+
and NO
3
-
have been recognized as beneficial for plant
growth (Castro
et al
., 1991). Root galling
and
M. incognita
reproduction efficiency in-
creased in tomato plants exposed to ammo-
nia at 76μg/m
3
, while treatments with higher
concentration (152μg/m
3
) caused nematode
suppression (Khan and Khan, 1995). Ad-
ditionally, urea and ammonium sulfate at
rates of more than 250mg N/kg soil resulted
in suppression of
M. incognita
population on
tomato plants (D’Addabbo
et al
., 1996).
Stimulation or depression effects of
some salts on various plant physiologi-
cal functions are already known, especially
when combined with other stressful agents
such as nematodes (Edongali and Ferris,
1982).
