Record ID No. |
1826 |
Author(s) |
Ngakou A., Tamo M., Parh I.A., Nwaga D., Ntonifor N.N., Korie S., Nebane C.L.N , 2008 |
Affiliation |
International Institute of Tropical Agriculture, 08 BP 0932 Tri Postal, Cotonou, BENIN |
Title |
Management of cowpea flower thrips, Megalurothrips sjostedti (Thysanoptera, Thripidae), in Cameroon |
Source. Vol.(no):Page |
Crop Protection.27(3-5):481-488p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
BENIN, Africa |
Abstracts |
A series of experiments were conducted in Cameroon to investigate options for
managing cowpea flower thrips, Megalurothrips sjostedti, via arbuscular mycorrhiza fungi,
rhizobia and Metarhizium anisopliae. Six cowpea fields were established in three agroecological
zones over a 3-year period. The abundance of both larvae and adults of M. Sjostedti was assessed
on plants grown from (1) seeds co-inoculated at sowing with arbuscular mycorrhiza fungi (AMF) and
rhizobia (mycorrhiza/rhizobia); (2) non-inoculated seeds and plants sprayed three times with M.
Anisopliae (Metarhizium); (3) seeds co-inoculated at sowing with AMF and rhizobia and plants
sprayed three times with M. Anisopliae (mycorrhiza/rhizobia/Metarhizium); (4) non-inoculated
seeds and plants sprayed three times with the synthetic insecticide deltamethrin; and compared
with (5) a control consisting of non-inoculated seeds and unsprayed plants. Results indicate that
thrips infestation was associated with the flowering cycle and was higher in the first than in
the second cropping season in most agroecological zones. In general, M. Sjostedti larval and
adult counts were significantly higher (P<0.01) in the control than in other treatments. Compared
with the control, treatment insecticide obtained the highest reduction of adults (range 52-95%)
and larvae thrips population (64-97%), followed by mycorrhiza/rhizobia/Metarhizium.(29-56%) and
(29-49%), mycorrhiza/rhizobia (31-49%) and (24-52%), and Metarhizium (25-58%) and (5-52%),
respectively. In all of the above treatments, the reduction of thrips led to a subsequent
increase of seed yield, although it was not always significant. Apart from two cases (Ngaoundere
2000 and Nkolbisson 1999), biological treatments (Metarhizium, mycorrhiza/rhizobia and
mycorrhiza/rhizobia/Metarhizium) consistently reduced grain yield loss in the trials compared
with the control at Ngaoundere in 1999 and Maroua 2001. These results are discussed in the
context of sustainable management of M. Sjostedti populations on cowpea. (C) 2007 Elsevier Ltd.
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