Applied Soil Ecology 45 (2010) 85–91
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Applied Soil Ecology
journal homepage: www.elsevier.com/locate/apsoil
Survival of the burrowing nematode Radopholus similis (Cobb) Thorne without
food: Why do males survive so long?
Christian Chabrier
a,∗
, Philippe Tixier
a
, Pierre-Franc¸ ois Duyck
a
,
Yves-Marie Cabidoche
b
, Patrick Quénéhervé
c
a
CIRAD, UPR Systèmes Bananes et Ananas, PRAM, BP. 214 97 232 Le Lamentin, Martinique
b
INRA, UR 1321 Agrosystèmes tropicaux, Domaine Duclos, UR 135 Agrpédoclimatique de la Zone Caraïbe, 97170 Petit-Bourg, Guadeloupe
c
IRD, UMR 186 Résistance des Plantes aux Bioagresseurs, PRAM, BP. 214 97 232 Le Lamentin, Martinique
article info
Article history:
Received 17 December 2009
Received in revised form 22 February 2010
Accepted 26 February 2010
Keywords:
Nematode survivorship
Pratylenchidae
Soil solution
Andosol
Nitisol
abstract
The burrowing nematode Radopholus similis is the most damaging banana nematode. To minimize
nematicide applications, cropping systems based on fallow, crop rotation, and using clean planting mate-
rial have been developed in the French West Indies. The survivorship of R. similis in water and soil was
evaluated to optimize the collapse of its populations during the intercropping period and to better under-
stand the risk of dissemination of nematodes by run-off water. In both Andosols and Nitisols, survivorship
was significantly higher for males than for females. After 180 days, 21.7% of males and 9.8% of females
were still alive, whereas no juveniles survived after 150 days. Survivorship was much lower in water and
soil solution than in soil. The mean half-life of males was 8.8 days and only 6.2 days for females, but the
difference between sexes was less after 1 month: 8% of both males and females in the initial population
survived after 35 days. These results suggest that resource allocation for males was directed towards
reproduction, whereas females expend energy foraging and laying eggs, and are thus disadvantaged in
the absence of host plants. The relatively long survivorship of males of R. similis enables them to fecundate
females without competing for food after becoming adults.
© 2010 Elsevier B.V. All rights reserved.
1. Introduction
The burrowing nematode Radopholus similis (Cobb) Thorne is
the nematode that causes the most damage to banana (Gowen et
al., 2005; Quénéhervé, 2009). To minimize nematicide applications,
cropping systems based on fallow, crop rotation and the use of
clean planting material have been developed in the French West
Indies. To optimize the benefit of the intercropping period and to
increase the economic sustainability of banana cropping systems,
we evaluated the survivorship of R. similis in soil.
In the absence of food, temperature, humidity and soil oxygena-
tion are considered to be the main limiting factors of nematode
survival (McSorley, 2003). Because of high mean temperatures in
the French West Indies, soil temperature is not assumed to be a
limiting factor for R. similis. Results of previous studies showed
that saturated soils were less favourable than drained and even
dry natural soils (Sarah et al., 1983; Chabrier et al., 2010). Evaluat-
ing the survivorship of R. similis survival in soil solution is crucial
to determine suitable conditions to minimize nematode longevity.
To this end, we evaluated the ability of the nematode to survive in
∗
Corresponding author. Tel.: +596 596 42 30 42; fax: +596 596 42 31 00.
E-mail address: christian.chabrier@cirad.fr (C. Chabrier).
water and in soil solutions that mimicked the environment of the
capillaries in which they live.
The length of time banana plants can be cultivated without R.
similis depends on the presence of alternative host plants (Duyck
et al., 2009) and the ability of this species of nematode to dissem-
inate and re-contaminate. In previous studies, we showed that R.
similis can be spread by run-off water (Chabrier et al., 2009). The
efficiency and the length of this dissemination process depend on
the nematode’s ability to survive in water.
In our previous study on survival in the soil (Chabrier et al.,
2010), despite the fact that females were more abundant in the
initial population, males were more abundant after 70 days in the
soil without food. The present paper presents results of investiga-
tions of the survivorship of R. similis in two types of soils, at different
degrees of humidity, in soil solution and in water, with particular
focus on the influence of sex.
2. Materials and methods
2.1. Survivorship in soil
Survivorship of R. similis was measured following the method
described by Chabrier et al. (2010) for the two main soil types on
which bananas are grown in Martinique: Andosol on pumice (sam-
0929-1393/$ – see front matter © 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.apsoil.2010.02.005