Formation et recherche en agroécologie horticole au Sénégal : exemples de deux études de cas portant sur les ravageurs du chou (Plutella xylostella) et de la tomate (Tuta absoluta) dans la zone des Niayes

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1

Par Karamoko DIARRA, Professeur

UCAD – DAKAR – SENEGAL; Email: karamoko.diarra@ucad.edu.sn

Réunion Réseau Africain de Travail sur les rongeurs Soudano-Sahéliens Elargie aux partenaires

Université Cheikh Anta DIOP, DAKAR, SENEGAL

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2

In Senegal, the university level training in agricultural-related fields is provided by four (/5) universities :

› Université de Thiès

› Université Gaston Berger › Université de Ziguinchor

› Université Cheikh Anta Diop › Université du SSK

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3

Université de Thies is recognized as the institution with a traditional undergraduate degree in agriculture:

B.S. in forestry and agriculture (ISFAR) at Bambey The instruction program focuses on :

•Integrated management of pests, •Horticulture

• Seed breeding and production,

•Forages, Animal nutrition and health •Cotton,

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4

Engineer in agronomy of Superior National School

of Agriculture (ENSA) at Thies

The instruction program focuses on : •Crop production,

•Livestock production,

•Agricultural economics and rural sociology, •Agricultural engineering

M.Sc. of Forestery

Formations

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5

University of Ziguinchor –UZ, a fourth university located in the Casamance region in the south . UZ has a department of Agriculture and Rural development.

It has developping more applied program of agro-forestry B.S. Degree

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Université Gaston Berger UGB is the second university in Senegal. It has recently initiated a College of

Agricultural Science, which complements programs in Economics and Business:

› B.S. in

› Agricultural Sciences › Aquaculture and

› Food Technology,

› Pre-B.S. Degree Programs Education includes use of farms

collaboratively operated

with local communities as well as the university farm

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7

Université Cheikh Anta Diop –UCAD is one of the

strongest university in west Africa

It has recently committed itself to develop

more applied programs of research and

training in agriculture, such as :

3 BS:

› B.Sc. Degree of Agriculture and

Entrepreneurship

› B.Sc. in Fisheries and Aquaculture

› Livestock production

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10 M.Sc.

› Plant and Microbial Biotechnology (BIOVEM) › Agroforestry, Ecology and Adaptation (AFECA) › Plant Production and Protection (PPV)

› Taxonomy, Biodiversity, Ethnobotany and Natural resources Management & Environment

› Sustainable Management of Horticultural Agro-Ecosystems (GEDAH)

› Nutrition and Food

› Fishing & aquaculture

› Chemistry & Analytical Aspects

› Quality Management in bio-industries

8

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6 Doctoral Training in agricultural science:

üPlant and Microbial Biotechnology and Plant Breeding

üAgroforestry and Ecology

üPlant Production and Protection

üKnowledge and Management of Biodiversity

üHorticulture and Urban and peri urban agriculture (2013)

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10

Recherche

Financement:

Programme Horizon Francophone de l’AUF et AI CIRAD

EC'OIE OOCifo:R..UE SCliENCES DEL~ \U, iDE LA SAllfiE !E'F. DE. L'!ID~i'\liRO?t-:.\"E..~

I'.~'C."ill"I.'rE DES SCIENCES Er TEC.-m,.,'IQUES

1BiEsE DE DOCIOR..U

spD!ife: iEutomologie·

Ga1Jo,S(]I1W

TIDi'e·: Q.sfioom~d.'es.populatiomde·PlN.~ ::c.y!osMio. L (I..EpidDpll!n:

~lliil!ae:, p:riDdJ!illl ~ur du dl.o1JI au. ~

Diredem de Ua!st : Km:il:Jm'loo, m:rum...t. Prof'e5iew: t:in.JWre.. Fs: 1UC~.

lembres : Ka:ndio'IIFd .. "OB .. >t, Prof55!!m ~ I .. ~· ·.

Dr. DooCJJiqu.e BOEDA:F'. O!m:h.irur HD.R.. cmAD ~

Dr. Emi::_ ViDior OOL Y lli'ecti!W' df! IKh.err.ll; ESRA1'CDH Dr.~ !B!RE\[;tUl.T, C'l':erdJsnr CJ:R.A.Th'Pe:i")'.it

Life, bis'I!11J !rails o:l l'l001yzus soto.lmvskii l(unljumuv {H'I'mellllplem: Euloplflfule}, a parasftoid ollhe dl11mondbact molb

G. Sow''. LArwl'l~akis". S. iassy''". K 1Jiari9J1

&n Bordar'

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lx~l]tnmllltltfTKJpcJ. fleitd~\bL33.No.l.pp.38-4S..2DlJ Cl~,r'W1.3

doi:ltU01?/S17f2?58.t1~

Performance of the parasitoid Oomyzus

sokolowskii (Hymenoptera: Eulophidae)

on its host Plutella. Xtjlostella.

(Lepidoptera: Plutellidae) under laboratory conditions

Gallo Sow'•, Laurence Arvanitakis2_,_Saliou_Niass_y', Karamoko Diarra1 and Dominique Bordat2 1

Laboratoire de Parasitologie, Depa.rtement de Biologic Animale~ Paculte des Sciences et Techniques, Equipc Production et Protection lntegrees en AgroCcosystemcs hortioolcs, Universite Cheikh Anta Diop de Dakar (UCAD), BP 5005, Dakar, Sen"l!!'~ 2_Laborat_oire_d_e_B_i_odi_versite

des all?ystcmes horticotes TAB/L, Campus intematimal de BatUarguet, ORAD, 34398 Montpelfier Cedex 5, France

Folia Hon. 2511 (2013): 3-12

DOt 1CI.247&'Ttlelrt·2D1J.OD[)1

ORIGINAL ARTICLE Open3CCM8

FoLIA

HoRTICULTURAE Pubtl6hed b)' the-Poll m Socle-;y

tor Hor11cl1~ Science-st~ce 1989

The relationship between the diamondback moth,

climatic facto•·s, cabbage crops and natu•·alenemies

in a tropical a1·ea Gal/o Soov', Karamoko Diarra'*, Loureuce .dn'OJ1ilokis1

, Domiuique Bordat'

' D@panement de Biolo~e-A.nimsle., FaOJ.lte des. Sciemes et Tec:hniques Equipe Produaion a ProtectioD IntegrH:s. eD AgrcH!c.osystfine-s B.onicoles UCAD, BP500S Dakar-Fann, S""'gal 2 _{Laboratoire- B}_i_od_h:ers:i_t_{i! des AgroKosys}_c_eme_s_eo_Horti

culmre-UR-HortSys, L~ B-103, Campus l!ll!emati.o!La.l de Baillarguet, CIR.AD

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r.mc:e-11

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Université Cheikh Anta DIOP de Dakar (UCAD)

K. Diarra et al. , EQUIPE 2PIA, UCAD, Dakar, Senegal

Seasonal abundance of major cabbage

insect pests and their natural enemies

in Senegal

Programme AIRD

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Introduction

—

In Senegal, insect pests are a major constraint to

the improvement of yield and quality of

vegetable crops

—

Chemical control is the main strategy developed

by farmers to protect their crop -> loss of

biodiversity, resistance, etc.

—

Need to design

ecologically-based

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Plutella xylostella

Lepidopteran pests of cabbage

(15)

Plutella xylostella Helulla undalis

Chrysodeixis chalcites Crocidolomia binotalis

Lepidopteran pests of cabbage

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Plutella xylostella (L.) ·

« T eigne du chou »

Lepidoptera ; Plutellidae

I Les: adultes de la c Teigne " sont de petits

papiltons de 15 mm de longueur enlfiroo. les ailes ant~rieures de la femelle ( 1' sont de

couleur brun clair avec une zone plus pale suT le oos.. les a!les du mile sont plus !Oocees, La zone

d01S3le est blanche (2).

l les arufs som dep~s de fa~on isolee ou par petits f.roupes ne depass:ant pas une vmgtame

d'umes (1~ A l'edosion, les chenilles penetrent

dans les feuiDes, faisant apparaitre des traces

blanches en fonne de virgule (4).

l l::les le OeUlci~me stade, el!es consomment le

dessous des feouilles (5) jusqua la nymphose qui

s'efl'ectue J;l!T la plante (6).. Par forte attaque, les feouilles sont perfomes de nombreux trous empe -ch;antla formation de lapomme (7)..

cirad

Hellula undalis (F.)

« Borer du chou »

Lepidoptera; Pyralidae

I L"aa:oup!ement (1) all1!11 des !'emergence des ~uhes..

I Le.s oeufs (2} sont d ~poses isolement sous

les feoui11es. Des leur eclosion, les chen;lles

pen~trent a l'interieur de la plante en se

concentrant dans les neTVUTes prindpales des

feuilles. O'autres se ~isent sur le bourgeon

central ~3) qu'elles devoren1,. puis penetreont dans

latige(4).

I La nymphose s'effeclue sur la planle au m!lr.eu

des excremen!s des chenU!es. Prives d'axe central,

les choux apparaissent pfats (5) et le depart

cle certains bourgeons allilla.!res provoque la

fonnation d'un chou a plusieurs pomme.s, le

ren-dant impropreab vente (6).

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Objectives

1.

Characterizing the major insect pests of cabbage

in the main vegetable-producing area in Senegal

(Niayes),

2.

Evaluating the impact of pest management

practices and natural enemies (especially

parasitoids) on the regulation of the diamondback

moth, Plutella xylostella (Lepidoptera:

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• 32 focal fields

Study area (Niayes)

— _Yearly

précipitations : 500 mm max.

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—

_{From October 2012 to January 2013}

(hot dry season), from transplanting to harvest,

—

24 plants per field were observed every three weeks:

plant diameter, number of major lepidopteran pests,

—

3089 larvae and nymphs were reared at the lab to

evaluate the rate of parasitism,

—

_{Cultural practices, including insecticide spraying,}

were recorded.

Monitoring

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—

P. xylostella was by far the major pest of cabbage

during this season, especially in the South of Niayes.

Pests and infestation

(21)

—

Parasitoids were mainly represented by

Oomyzus sokolowskii (Hymen., Eulophidae).

Parasitoids and parasitism

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—

The percentage of parasitized larvae varied

from 0 to 33% according to fields (n=3090).

Parasitoids and parasitism

% parasitism (P. xylostella) Max Min

a*

b

c

*GLM Logistic regression

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—

The percentage of parasitized larvae

decreased with time…

Parasitoids and parasitism

% parasitism

(P. xylostella)

a*

b

c

*GLM Logistic regression

Nb days post transplanting

c

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—

_{A positive correlation between the percentage of}

infested sprouts and the number of insecticide

treatments performed was observed, suggesting low

efficiency of treatment and putative insecticide

resistance in populations of the diamondback moth.

Insecticide and resistance

% infested sprouts (transf. asin√)

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Conclusion et Perspectives

—

Plutella xylostella is the major pest for cabbage

in Senegal

—

Biological control could be an alternative to

insecticide use, provided …

—

This study, to continue with a new range of

variables including landscape, should contribute

to improve management practices of insect pests

towards an "ecologically-based" intensification

of agricultural production systems.

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Tuta absoluta,

une nouvelle menace pour

la production de tomate au S

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Tuta absoluta (Meyrick) ·

Lepidoptera ; Gelechiidae

I Les aduttes de 5 mm environ sont de couleur

brun griJatre (1). A l'edOSJoo, la cnen'Jie (2'

penetre dans la l"euiDe et mine le pareocnyme.

I Les feuilles attaquees se dessechent ( 3). La

chenille penetre dans la tige et mme celle-ci 14 ).

91e peut egalement s'attaquer au fruit (S }. I La nymphose s'effectue sur la feuiUe dans un

cocon SO)'I!UX (6).

Gl-C't)o...l,

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D

é

tection de

Tuta absoluta

en cultures de

tomate plein champ dans la zone des Niayes

Méthodologie

— Suivi d’un réseau de

parcelles

— Sud, centre et nord Niayes

— Observation toutes les

trois semaines de 3 feuilles sur 24 plants par parcelle

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D

é

tection de

Tuta absoluta

en cultures de

tomate plein champ dans la zone des Niayes

Saison 1 (24 parcelles) Octobre-décembre 2012

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Saison 1 (24 parcelles)

Octobre-décembre 2012 Saison 2 (26 parcelles)Février-avril 2013

D

é

tection de

Tuta absoluta

en cultures de

tomate plein champ dans la zone des Niayes

Tuta absoluta Tuta absoluta

clans les Niayes (Senegal) clans les Niayes (Senegal)

• absence e absence

• presence e presence

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D

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D

é

gâts sur feuilles de tomate

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D

é

tection de

Tuta absoluta

sur d

’

autres cultures de Solanac

é

es

—

aubergine

(Solanum melongena)

—

diakhatou

(35)

T. Brévault1_{, O. Ndoye}2_{, M.}

Diatte3_{, S. Sylla}3_,

G. Bernadas1_,

S. Gueye2 _{& K. Diarra}3

Programme Peers-Biobio

Une r

é

elle menace pour la fili

è

re mara

î

ch

è

re!

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Programme

Programme «« Doctorants du Sud 2013Doctorants du Sud 2013 »»sur le sujet sur le sujet «« Invasion de la Invasion de la

mineuse de la tomate, Tuta absoluta, en Afrique sub

mineuse de la tomate, Tuta absoluta, en Afrique sub--saharienne : saharienne :

dynamique, niche

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