COWPEA BREEDING IN SENEGI _ : RECENT DEVELOPMENTS' ...
COWPEA BREEDING IN SENEGI _ : RECENT DEVELOPMENTS'
NDIAGA
CISSE’
I- INTRODUCTION
Plant breeding has been dr 'ined as the current phase of trop
evo1 ution where artificial Select ioi is predominant (Simmonds, 1979).
There are many choices to be made ii a breeding program. An important
one is the choice of parental germp 1s.m to include in the program. As
a result of trop evolution and of p int breeding, local adaptation is
always present. Rapid and more relit Ile progress cari be achieved wor-
i,.
king with locally adapted parental I Iterial. This Will include; Strains
which, from performance in collectil 1 offer local adaptation OV specific
desired characters, and locally SUC~ zssful varieties. Selection of parents
cornes after the first decisions whil 1 are definition of objectives. Objec-
tives are defined on the basis of ki jwledge of the environment or the
group of similar environnient of inti -est and of the genetic features of
the trop.
From a collection made in :he fifties and subsequent yield
trials, very adapted and high yield lg materials have been identified ;
Among these, are 58-57 and "Peut" a )hotosensitive line (Sene, 1971 ;
Cisse, 1985a) the former has been rl leased as a variety and was used to
develop "Ndiambour", while the latte - has mainly served to create another
successful variety ; "Mougne".
l- Paper presented at the "Safgrad Seminar
Jr advanced national programs"
Held at III’A/Iba in from 14 to 25 November, 1988.
2 - Plant breeder, ISRA/CNRA Bambey - B.P. 5
-Ii-
II - OBJECTIVES
-
-
-
2.1 - Drouqht resistance
Cowpea is grown mainly in the North central area of Senegal this
correspond to the Louga, and part of Dit urbel regions. Rainfall has varied
between 151 to 381 mm from 1970 to 1985 with 13 years out of 16 averaging
below 300 mm and 4 not reaching 200 mm
Dancette, i!lt84). Along with the r~k
rainfall, the lengith of the wet season
as become as low as 45-60 days.
Drought is then prevalent in the area w, ere 70 % of cowpea acreage and
60 % of the production are realized.
Obtaining drought resistant vI rieties has evidently been consi-
dered as a high priority objectiv (Cissr , 1985b, 1986). Appropriate adap-
tation of trop varieties to the modal l( ngZh of the period available for
growth, wether determined by climate or by cultural practices, is of the
greatest importance (Bunting, 1985). Bic chemical or biophysical attributes
which enable plants to withstand the COI Fequences of diurnal or Longer
periods of water shortage are important
lso, but the attributes relating
to time and space are still,more import;
t according to Bunting. The relativ
success of the 1985 CB5 program in Sene!
1, appeared to support this view
(Mersch, 1985). Rainfall totalled 208 mr in the Louga station and was recorded
between July 20 and September 15. The pr gram success was essentially due to
the short cycle of the variety CB5 (60 d ys). Yield trials have previously
shown that earliness confers better adap ation in the semi-arid zones (Cisse,
1985).
Regression techniques (Finlay
Wilkinson 1963), when applied to
the “CIISS project" 4 years yield tria1
ata have shown, that 58-57, Mougne,
TN 88-63, gorom gorom are stable varieti s in Senegal with high yield poten-
tial but are medium to late maturing (Ci
One of the breeding program ob
s to improve 58-57 and
Mougne for earliness ; several crosses w
de. Some of the early
parents used are Bambey 21, CB5, IT82E-6
2 . 2 - Insects resistance
Bruchids (Callosobruchus macu
pest of cowpea. The damage is done by la
cstimated that up to 30 per cent loss in
infested seed becoming unfit for consump
storage period (Singh, 1985).
-3-
The released varieties (58-57
Mougne, Ndiambour, CB5) are a11
susceptible to bruchid. The pest is als
continuously present in a11 the
cowpea production area and is the singl
most limiting factor in successful
storage. Resistance in these conditions
ay then afford significant advantages.
From 1984 a breeding program
s initiated to improve 58-57 and Mougne
for bruchid resistance. The line IT81D
031 has been used as resistance Sourc(e.
Yhe germplasm collection at Bambey was
reened for resistance to this pest, none
of the accessions did have an acceptabl
Three insect species cari caus
damage to cowpea in the field
(Amsacta, Aphids, Thrips).
Hairy caterpillar (Amsacta mo
ch is specific to Senegal cari
completely destroy seedlings of cowpea,
ut causes little economic damage to
older plants. A germpiasm accessions (5
een reported as having some
field resistance to this pest (Sene, 19
as not been confirmed and any
other source of resistance has not been
due to unadequate screening
techniques.
Aphids (Aphis craccivora) wer
for the first time in 1984,
and have become important the followin
hids primarily infest seed-
lings, at a later stage pods cari also b
Large populations cari reduce
*yield, and in extreme cases the plant d
& Jackai, 1985).
The reported aphid resistant
as been tested against the
local pest population. Two lines (TVU 3
42-13) are used as resistant
parents in crosses with the susceptible
eties (58-57, Mougne, B21,
CB5).
Flower thrips (TaenioThrips s
amage was observed every year
at the Nioro area, in the wetter part o
Much less damage due to flower
thrips bas been observed in the drier p
y.- Louga area). The germplasm
collection was screened for resistance
thrips mainly at Nioro. The
screening method consists of sowing guar
rows 10-15 days earlier and around
&he test plots, this is intended to bui
r thrips population, and the
e.xperiment is unsprayed. Resistance is
ased upon the relative number
of pods produced and upon the thrips po
namics.Known resistance source
(TVX 3236) is also used in cross with 1
tible varieties.
- 4 -
2.3 - Diseases resistance
Survey of diseases, in the ma n cowpea production area has shown
that are prevalent ;
mosaic viruses (c wpea Aphid borne mosaic and cucumber
mosa ic), bacterial blight (caused by Xa
- thomonas campestris pv, Vignicola) ;
bacterial pustule (a strain of the bact rial blight organism), cercospora
leaf spot (cercospora cruenta) ashy Ste' blight (Macrophomina phaseolina)
lamb's Tail pod rot (Choanephora cucurb tarum), powdery mildew (Erysiphe
polygoni), web blight (Rhizoctonia sola i) (Patel, 1984-85-86-88, Gaikwad,
1987 ) .
Mosaic are very widespread an
most severe in the principal variety
(58-57) while Bambey 21 and TVX 3236 arl
consistently free of mosaic for the
last 4-5 years. Mougne and Ndiambour sh
mild mosaic symptoms. Yield loss due
to virus diseases was estimated at 20 %
Gaikwad, 1988).
Bacterial blight is most sever
in B21 and CB5, but field resistant
Ndiambour and 58-57 show some blight in
eaves. Yield loss due to bacterial
blight on Bambey 21 and CB5 cari be up to 40 % (Gaikwad, 1988).
Bacterial pustule disease is o served on a11 varieties CB5, B21,
Ndiambour, Mougne, 58-57.
Striga (Striga gesneroides) pr viously restricted to small areas, is
now encountered.in several villages.
Cercospora leaf spot is freque tly encountered in the cowpea area whille
Ashy stem blight is more restricted and
ppears in places where plants suffer
from some water stress (Patel, 1988).
Breeding act ivites have conter ed particularly mosaic virus d iseases
and bacterial blight.
III - RESULTS
3.1. - Yield potential and trop adapdation
E
Selection has been done from t
different crosses made to achieve
the objectives defined. Up to now 456 li
s have been yield tested. The pro-
cedure consist of running preliminary yi
d triais at one location ; Bambey.
The experimental designs used are random
ed complet blocks with 2 replications.
High yielding lines (Better or as good a the local checks) with good agronomie
-5-
attributes are afterwards introduced i advanced yield trials for 2 years.
i
These triais are conducted in 4 statio
and sub-stations (Bambey, Thilmakha,
Louga, Ndiol) covering the main cowpea
roduction area. Randomized complet
hlock designs are also used but with 4
The 1986 and 1987 trials hav
ery high yielding lines
have been obtained (Tables X, 2, 3).
med by the 1988 results
(Cisse, under press). Of particular in
line IS 86-275 which is
as productive as the local variety 58-
ier, although the cross
(58-57 x IT81D 1137) from which it is
ntended to improve 58-57
for bruchid resistance. A nother high
dapted line is IS86-283.
3.2 - Insect Resistance
The first objectiv of this
considered, was the improvement
of the local varieties (58-57' Mougne,
ambey 21) for bruchid resistance. The
resistant parents used were IT81D-il37
2. The best promising lines
obtained with bruchid resistance, as m
ve are 1~86-275, Is86-279,
11~86-283 with respectively 21 %, 26,8
dult emergency. The variety
58-57 has 56,3 % adult emergency.
Lines with significantly lowe
thrips population than TVX 3236
have been identified from the germplas
58-145, 58-1, 58-77)
(Gahukar, 1986) and from crosses betwe
ne and TVX 3236 (Bal, 1987),
Several crosses with di'ffere
s between 58-57, Mougne,
Elambey 21, CB5 and aphid resistant lin
IT83s-742- 13 ; IT84E- l- 108)
have been obtained. About 382 F6, F5 s
lection Will next be scree-
ned for aphid resistance and yield tes
3.3 -Disease resistance
The strategy SO far followed i
initial selection pressure for insect
resistance and others superior agronomi
traits and then screen the advanced
.
lines against diseases. Generally large
umber of lines are retained for latter
screening from crosses involving
sistant parent to bacterial
blight and/or aphid borne mosaic virus.
his strategy has some drawbacks ; Among
the thr,ee high yielding advanced b
eneration),
1s 86-275 is a
mixture of resistant and susceptib
was uniformly susceptible
and IS86-283 is susceptible to mod
to virus disease. Al1 the
three promising lines have a heter
o bacterial blight. Single
plant selection is made out of 1~8
population. These plants
are to be screened for bacterial b
es and bruchid resistance.
-6-
it is clear that a more reliable approac
is direct positive screening of
segregating populations in early genera ions and continued at a11 gene-
rations (Patel, 1988).
- 7-
Table 1 : Advanced yield tria1 1.
- - -
-~_-. _ _-
I
1
Bambey - Thilmakha /l? nbey - Thilmakha - Louga
/
1
Ndiol
/
L-ines
-l_---- -I_- -
- - -
/
1
Seed
rd.to Mat1
jeed
/d.to MatJ 100 seed 1 Seed
j
I
/
'$g/ha)
i
cg/ha) i
iJ)
/‘weight (9) 1 (kg/ha) ,
,
- - .--- .---!!L.- / .- -- ._.____ -.-‘._-_._.__ ’ _. ---.~- ’ .~ _-__- 1
/
IS86-239 N
/
1189.9
’
63.2 /
I
1393.3
I
, 652 .
I
15.3
;
132.5
I
58- 57
1663.7
64.6 I 1371.6
I
67.b
,
1 2
I 390
IS86-283 N
1652.6
!
62.4 /
1280.9
j67
1
22.7
’
1 S8b- 269 N
1616.4
/
64.2 1 1269.2
;
66.7
i
15.9
1 231.b 172.6
IS86-292 N
1596.6
1
j
64.2
/
1272.7
’
67.7
)
16.6
,
207.6
1 IS86-276 N
i 1542.9
i
62.9 1 1195.2
/
64.7
/
1 6
/
/
TVX 3236
j
1445.6
i 65.7 /
1105.4
j 62.8
’
11.6
/
167.7
,
102.5
I IS86-310 N
165
1 1161
1
67.6
i
18.5
1 119.3
’
IS86-245 N
/ 141fjs5
/ 66.5 j
1095.4
/
69
i
15.1
/
211.3
; IS86-235 N
I
1399.3 1384.5
/ 62.2 I
1052.2
1 64.4
;
18.3
1 IS86-247 N
; 66.6
j
I
’
1053.8
/ 67.6
/
15.9
/ Mougne
/
1374.5 1332.5
1
62.2 1 1046.7
1 62.3
1
14.7
/ IS86-309 N
;
1297.9
1 63.2 1 1002.7
’ 64.7
/
16.1
I IS86-252 N
1 1279.4
I
61.2 1 1015.5
1
63.2
1
15.5
1 132.5
!
i --
I
l
-
l
-.-_
l
i
I
I
j Mean ( x >
1485.2
63.9
1165.4
66.2
16
213.& -7
i
C.V. (%)
11.6
2.3
13.5
3.6
3.3
38.3
1
; LSD 0~5
171.3
1.4
127.5
1.9
0.4
118.4
/
-.-
_----I_-~
_- I
- 8
Table 2 : Advanced yield tria1 II.
-
-
-
/ .._-.___-_.. T.--.
- - - -
-
-
T------------
--- --
/
Bambey-Thilmakha
/Bambey-Thilmakl
- -~ --l--.-I
Lines
j
Louga
/
Ndiémane
, Ndiol
i
-
----.---I---p
I-----
I
I
l
Seed
d.to Mat! Seed
!d.to I
d.to Mat
Dry
1 Seed
I
/
I i
i ikghd j
: Matter
l
kgha)
I
t kg/tW )
f-.- ____.__ -_ -
..-.--- - - -
- ’ -<--- ’
j
58-57
I 1394.2
64.6
1 1083.7 /
67.1
65.2
3850 / 167.5
/
I IS86-237N
1350.9
60.2
I 1025.6 1
61.;
1 13.9
I 1250
59.5
2050 I 180.5 I
I
’
1%6-279N !I 1299.1
61.4
j
986.9 /
62.1
1 16.8
j 2081.9
58.5
2750 j 277.5
j
Mougne
I 1251.1
62.5
/ 984.1 I 64.1
I 14.4 i 1110.5
59.5
3408 l 445
I
[ .
/
1586-286N l 1248.9 j
59.7
/
965.9 i
61.1
1 13.6
j 1550 /
60.2
2150 j 337.5
/
/ IS86- 299N I 1239.5 I
62.1
/
943
I
63.;
I 17.6
I 1218.61
56.9
3313.7 ( 230
!
j TVX 3236
1214.9 /
67.6
926.6
69.;
1
/
/
1 li.3
/ 1450 j
6 4
4350 / 323
I
/
IS86-259N
1205.6 I 63.2
937.6 1 65
I 20.9
/ 1594.31
58.3
3430.9) 166.9
/
IS86-93 N
l129.6 /
65.1
/
919.7
65..
j 20
j 1007.8, '
60
3008.1; 302.5
;
IS86-76 N I 1094.6 I
64.5
833.9 i
65.1
/ 14
1
778.41
60.5
3276.81 412.5
j
/
IS86-241N 1 1057.2 j
61.5
858.9 1
64.1
I 15.9
j 1000
/
60
3175
I
IS86-253N
11033
1 62.2
792.8 I 65
1 13.5
1 1500
58.7
2400
295
1
j IS86-185N
1.009.6 /
57.6
785.6 j
60.3
/ 10.6
1 il75
56.5
3025
382.5
/
"
1 IS86-217N
1007.7 I
55.4
813.5 ! 57.5
I 13.5
I 1500
55.2
2900
315
I
j IS86-114N / 1006.5 j 58 !
779.3 j 60.5
j 12.3
i 1200
57.7
185
I
3375
,
/ IS86-2 N I
945.9
57.4
768.1 1 59.7
I 14.6
i 1175
56.2
4025
172.5
I
j IS86-168N/
826.9
58.4
/
734.6
60.3
j 14.8
1
886.6
59.6
2821.3
237.5
j
l IS86-224N/ 633.9
57.1
1
472.6
58.7
i 13.8
i
375
l
57
1725
1 110
l
I--.- --!--
1
- - - -
I
!-
1
l
i ..-~- --
I
-I---
) Mean (x)
1108.3
61
867.3
62.9
14.6
1392.3
66.5
3439.6
259
I
/
/ C.V. s
15.2
3.4
17.9
3.1
3.9
24.9
1.9
26.9
54.6 /
/ LSD 0.05
167.3
2
125.9
1.6
0.5
491.5
0.8
1321.4
200.8 /
- 9-
T a b l e 3 : Advanced yield tria1 III.
) Bambey - Thilmakha
I
fi
Bambey - Thilmakha - Louga
I
l
l
Lines
1 Seed
!CiMatter/
Seed
1 d. to Mat.
I
1100 seed
1 ( Wha) 1
(kg/hd
/
1 weight (g)
- - -
_--
-~-_
I-
I-
---+:
;
IS86-275 N /
1332
I
60.2
1196.3
j
61.6
1
16.6
!
i 58-57
I
1302.2
1
63.9
1105.6
(
65.4
I
12.1
/ TVX 3236
/
1281.9
j
64.5
1033.8
/
66
11.6
Mougne
I
1167.4
l
62.2
1019.9
1
63.8
14.9
l
IS86-63 N
j
1109.6
/
6 3
918.9
,
6 5
19.1
(
IS86-219 N
I
1080.9
I
56.1
845.6
1
58.9
i
13
l
IS86-248 N
l
1075.3
l
59.5
900.2
1
60.7
1
14.4
/
IS86- 140 N
I
1036.2
/
59
965.8
60*4
12.3
l
1 IS86-191 N
/
1015.9
l
52.9
889.8
1
l
56.1
12.7
1
I IS86-174 N
I
984.1
1
54.5
876.9
i
57.7
1
13.2
1
/ IS86-218 N
I
9 3 3 . 2
/
5 3 . 9
780.4
/
56.5
/
12.8
j
I IS86-48 N
1
914.8
1
56.9
/ IS86-36 N
;
906.6
;
57.7
709.9
1
59.1
I
14*6
l
1
733.6
1
59.4
12.6
/
""
I Bambey *l
I
726.6
1
58.9
626.1
1
61*4
I
18.1
1 IS86-121 N
l
703.9
1
56.6
527.6
I
59.4
j
11.4
1
i
I IS86-1'70 N
1
619.6
I
55.2
496.4
1
58.7
I
14.1
I
/
I
Mean
(X)
1011.9
58.4
851.7
60.6
13.9
1
,
C.V. %
19.6
2.8
25.2
2.5
3.7
l
LSD
0.05
196.7
1.6
173.5
1.2
0.4
i
::.1.:
- - - -
REFERENCES
Bal, A.B., 1987 - Rapport d'activités 1
I. ISRA-CNRA - Bambey.
Esunting, A.H., 1985 - What is this thin
:alled drought, workshop on drought
of the bean-cowpea CRSP, Durai
I, Mexico, 26-28 Août 85.
Cissé, ND.,- 1985a - L'amélioration du I ;bé au Sénégal. Dans travaux et docu-
ments du CILSS no 3, 4-8.
Cissé, ND., - 1985b - Project CRSP niébc
Rapport annuel 1984. ISRA-CNRA - Bambey.
Cissé, ND., - 1986 - Amélioration du n-ii
. Projet CRSP-niébé - Rapport annuel
1985 - ISRA-CNRA - Bambey.
Cissé, ND., 1987 - Amélioration du niébr
Projet CRSP - Rapport annuel 1986.
ISRA-CNRA Bambey.
Cissé, ND., 1988 - Amélioration du niébi
irojet CRSP-niébé - Rapport annuel 198;' -
ISRA-CNRA Bambey.
Dancette, C., - 1984 - La résistance du
ébé à la sécheresse sous climat soudano-
sahélien. Etudes techniques dl
:NRA no 10.
Cinlay, K.w. & Wilkinson, G.N., 1963 -
analysis of adaptation in a plant
breeding program. Aust. J. Ag
Res., 1963, 14.
?
Gahukar, 1986 - CILSS project annual rei
t.
Gaikwad, D.G., 1987 - Annual report on I rpea phytopathology 1986. ISRA-CNRA
Bambey.
Gaikwad,, D.G., 1988 - Annual report on ' rpea pathology 1987.
Mersch, 1985 - Operation niébé 1985 - DI
igation de la CEE - Dakar.
Patel , P.N., 1984, 1984, 1985, 86, 88 -
Ian-cowpea CRSP Trip report. UCR
Riverside Ca.
Sene, D., 1971 - L'amélioration du niébl
u CNRA de Bambey de 1959 à 1969.
L'agronomie tropicale no 26.
Simmonds, N.w., 1979 - Principles of cri
improvement.
Longman 1979. pp. 408.
Singh, S'.R. ; Jackai, L.E.N., 1985. Ins
: pests of cowpeas in Africa : Their
life cycle, Economie importan'
and potential control. In cowpea research,
production and utilization. Ji
I
wilev 1985.
NDIAGA
CISSE’
I- INTRODUCTION
Plant breeding has been dr 'ined as the current phase of trop
evo1 ution where artificial Select ioi is predominant (Simmonds, 1979).
There are many choices to be made ii a breeding program. An important
one is the choice of parental germp 1s.m to include in the program. As
a result of trop evolution and of p int breeding, local adaptation is
always present. Rapid and more relit Ile progress cari be achieved wor-
i,.
king with locally adapted parental I Iterial. This Will include; Strains
which, from performance in collectil 1 offer local adaptation OV specific
desired characters, and locally SUC~ zssful varieties. Selection of parents
cornes after the first decisions whil 1 are definition of objectives. Objec-
tives are defined on the basis of ki jwledge of the environment or the
group of similar environnient of inti -est and of the genetic features of
the trop.
From a collection made in :he fifties and subsequent yield
trials, very adapted and high yield lg materials have been identified ;
Among these, are 58-57 and "Peut" a )hotosensitive line (Sene, 1971 ;
Cisse, 1985a) the former has been rl leased as a variety and was used to
develop "Ndiambour", while the latte - has mainly served to create another
successful variety ; "Mougne".
l- Paper presented at the "Safgrad Seminar
Jr advanced national programs"
Held at III’A/Iba in from 14 to 25 November, 1988.
2 - Plant breeder, ISRA/CNRA Bambey - B.P. 5
-Ii-
II - OBJECTIVES
-
-
-
2.1 - Drouqht resistance
Cowpea is grown mainly in the North central area of Senegal this
correspond to the Louga, and part of Dit urbel regions. Rainfall has varied
between 151 to 381 mm from 1970 to 1985 with 13 years out of 16 averaging
below 300 mm and 4 not reaching 200 mm
Dancette, i!lt84). Along with the r~k
rainfall, the lengith of the wet season
as become as low as 45-60 days.
Drought is then prevalent in the area w, ere 70 % of cowpea acreage and
60 % of the production are realized.
Obtaining drought resistant vI rieties has evidently been consi-
dered as a high priority objectiv (Cissr , 1985b, 1986). Appropriate adap-
tation of trop varieties to the modal l( ngZh of the period available for
growth, wether determined by climate or by cultural practices, is of the
greatest importance (Bunting, 1985). Bic chemical or biophysical attributes
which enable plants to withstand the COI Fequences of diurnal or Longer
periods of water shortage are important
lso, but the attributes relating
to time and space are still,more import;
t according to Bunting. The relativ
success of the 1985 CB5 program in Sene!
1, appeared to support this view
(Mersch, 1985). Rainfall totalled 208 mr in the Louga station and was recorded
between July 20 and September 15. The pr gram success was essentially due to
the short cycle of the variety CB5 (60 d ys). Yield trials have previously
shown that earliness confers better adap ation in the semi-arid zones (Cisse,
1985).
Regression techniques (Finlay
Wilkinson 1963), when applied to
the “CIISS project" 4 years yield tria1
ata have shown, that 58-57, Mougne,
TN 88-63, gorom gorom are stable varieti s in Senegal with high yield poten-
tial but are medium to late maturing (Ci
One of the breeding program ob
s to improve 58-57 and
Mougne for earliness ; several crosses w
de. Some of the early
parents used are Bambey 21, CB5, IT82E-6
2 . 2 - Insects resistance
Bruchids (Callosobruchus macu
pest of cowpea. The damage is done by la
cstimated that up to 30 per cent loss in
infested seed becoming unfit for consump
storage period (Singh, 1985).
-3-
The released varieties (58-57
Mougne, Ndiambour, CB5) are a11
susceptible to bruchid. The pest is als
continuously present in a11 the
cowpea production area and is the singl
most limiting factor in successful
storage. Resistance in these conditions
ay then afford significant advantages.
From 1984 a breeding program
s initiated to improve 58-57 and Mougne
for bruchid resistance. The line IT81D
031 has been used as resistance Sourc(e.
Yhe germplasm collection at Bambey was
reened for resistance to this pest, none
of the accessions did have an acceptabl
Three insect species cari caus
damage to cowpea in the field
(Amsacta, Aphids, Thrips).
Hairy caterpillar (Amsacta mo
ch is specific to Senegal cari
completely destroy seedlings of cowpea,
ut causes little economic damage to
older plants. A germpiasm accessions (5
een reported as having some
field resistance to this pest (Sene, 19
as not been confirmed and any
other source of resistance has not been
due to unadequate screening
techniques.
Aphids (Aphis craccivora) wer
for the first time in 1984,
and have become important the followin
hids primarily infest seed-
lings, at a later stage pods cari also b
Large populations cari reduce
*yield, and in extreme cases the plant d
& Jackai, 1985).
The reported aphid resistant
as been tested against the
local pest population. Two lines (TVU 3
42-13) are used as resistant
parents in crosses with the susceptible
eties (58-57, Mougne, B21,
CB5).
Flower thrips (TaenioThrips s
amage was observed every year
at the Nioro area, in the wetter part o
Much less damage due to flower
thrips bas been observed in the drier p
y.- Louga area). The germplasm
collection was screened for resistance
thrips mainly at Nioro. The
screening method consists of sowing guar
rows 10-15 days earlier and around
&he test plots, this is intended to bui
r thrips population, and the
e.xperiment is unsprayed. Resistance is
ased upon the relative number
of pods produced and upon the thrips po
namics.Known resistance source
(TVX 3236) is also used in cross with 1
tible varieties.
- 4 -
2.3 - Diseases resistance
Survey of diseases, in the ma n cowpea production area has shown
that are prevalent ;
mosaic viruses (c wpea Aphid borne mosaic and cucumber
mosa ic), bacterial blight (caused by Xa
- thomonas campestris pv, Vignicola) ;
bacterial pustule (a strain of the bact rial blight organism), cercospora
leaf spot (cercospora cruenta) ashy Ste' blight (Macrophomina phaseolina)
lamb's Tail pod rot (Choanephora cucurb tarum), powdery mildew (Erysiphe
polygoni), web blight (Rhizoctonia sola i) (Patel, 1984-85-86-88, Gaikwad,
1987 ) .
Mosaic are very widespread an
most severe in the principal variety
(58-57) while Bambey 21 and TVX 3236 arl
consistently free of mosaic for the
last 4-5 years. Mougne and Ndiambour sh
mild mosaic symptoms. Yield loss due
to virus diseases was estimated at 20 %
Gaikwad, 1988).
Bacterial blight is most sever
in B21 and CB5, but field resistant
Ndiambour and 58-57 show some blight in
eaves. Yield loss due to bacterial
blight on Bambey 21 and CB5 cari be up to 40 % (Gaikwad, 1988).
Bacterial pustule disease is o served on a11 varieties CB5, B21,
Ndiambour, Mougne, 58-57.
Striga (Striga gesneroides) pr viously restricted to small areas, is
now encountered.in several villages.
Cercospora leaf spot is freque tly encountered in the cowpea area whille
Ashy stem blight is more restricted and
ppears in places where plants suffer
from some water stress (Patel, 1988).
Breeding act ivites have conter ed particularly mosaic virus d iseases
and bacterial blight.
III - RESULTS
3.1. - Yield potential and trop adapdation
E
Selection has been done from t
different crosses made to achieve
the objectives defined. Up to now 456 li
s have been yield tested. The pro-
cedure consist of running preliminary yi
d triais at one location ; Bambey.
The experimental designs used are random
ed complet blocks with 2 replications.
High yielding lines (Better or as good a the local checks) with good agronomie
-5-
attributes are afterwards introduced i advanced yield trials for 2 years.
i
These triais are conducted in 4 statio
and sub-stations (Bambey, Thilmakha,
Louga, Ndiol) covering the main cowpea
roduction area. Randomized complet
hlock designs are also used but with 4
The 1986 and 1987 trials hav
ery high yielding lines
have been obtained (Tables X, 2, 3).
med by the 1988 results
(Cisse, under press). Of particular in
line IS 86-275 which is
as productive as the local variety 58-
ier, although the cross
(58-57 x IT81D 1137) from which it is
ntended to improve 58-57
for bruchid resistance. A nother high
dapted line is IS86-283.
3.2 - Insect Resistance
The first objectiv of this
considered, was the improvement
of the local varieties (58-57' Mougne,
ambey 21) for bruchid resistance. The
resistant parents used were IT81D-il37
2. The best promising lines
obtained with bruchid resistance, as m
ve are 1~86-275, Is86-279,
11~86-283 with respectively 21 %, 26,8
dult emergency. The variety
58-57 has 56,3 % adult emergency.
Lines with significantly lowe
thrips population than TVX 3236
have been identified from the germplas
58-145, 58-1, 58-77)
(Gahukar, 1986) and from crosses betwe
ne and TVX 3236 (Bal, 1987),
Several crosses with di'ffere
s between 58-57, Mougne,
Elambey 21, CB5 and aphid resistant lin
IT83s-742- 13 ; IT84E- l- 108)
have been obtained. About 382 F6, F5 s
lection Will next be scree-
ned for aphid resistance and yield tes
3.3 -Disease resistance
The strategy SO far followed i
initial selection pressure for insect
resistance and others superior agronomi
traits and then screen the advanced
.
lines against diseases. Generally large
umber of lines are retained for latter
screening from crosses involving
sistant parent to bacterial
blight and/or aphid borne mosaic virus.
his strategy has some drawbacks ; Among
the thr,ee high yielding advanced b
eneration),
1s 86-275 is a
mixture of resistant and susceptib
was uniformly susceptible
and IS86-283 is susceptible to mod
to virus disease. Al1 the
three promising lines have a heter
o bacterial blight. Single
plant selection is made out of 1~8
population. These plants
are to be screened for bacterial b
es and bruchid resistance.
-6-
it is clear that a more reliable approac
is direct positive screening of
segregating populations in early genera ions and continued at a11 gene-
rations (Patel, 1988).
- 7-
Table 1 : Advanced yield tria1 1.
- - -
-~_-. _ _-
I
1
Bambey - Thilmakha /l? nbey - Thilmakha - Louga
/
1
Ndiol
/
L-ines
-l_---- -I_- -
- - -
/
1
Seed
rd.to Mat1
jeed
/d.to MatJ 100 seed 1 Seed
j
I
/
'$g/ha)
i
cg/ha) i
iJ)
/‘weight (9) 1 (kg/ha) ,
,
- - .--- .---!!L.- / .- -- ._.____ -.-‘._-_._.__ ’ _. ---.~- ’ .~ _-__- 1
/
IS86-239 N
/
1189.9
’
63.2 /
I
1393.3
I
, 652 .
I
15.3
;
132.5
I
58- 57
1663.7
64.6 I 1371.6
I
67.b
,
1 2
I 390
IS86-283 N
1652.6
!
62.4 /
1280.9
j67
1
22.7
’
1 S8b- 269 N
1616.4
/
64.2 1 1269.2
;
66.7
i
15.9
1 231.b 172.6
IS86-292 N
1596.6
1
j
64.2
/
1272.7
’
67.7
)
16.6
,
207.6
1 IS86-276 N
i 1542.9
i
62.9 1 1195.2
/
64.7
/
1 6
/
/
TVX 3236
j
1445.6
i 65.7 /
1105.4
j 62.8
’
11.6
/
167.7
,
102.5
I IS86-310 N
165
1 1161
1
67.6
i
18.5
1 119.3
’
IS86-245 N
/ 141fjs5
/ 66.5 j
1095.4
/
69
i
15.1
/
211.3
; IS86-235 N
I
1399.3 1384.5
/ 62.2 I
1052.2
1 64.4
;
18.3
1 IS86-247 N
; 66.6
j
I
’
1053.8
/ 67.6
/
15.9
/ Mougne
/
1374.5 1332.5
1
62.2 1 1046.7
1 62.3
1
14.7
/ IS86-309 N
;
1297.9
1 63.2 1 1002.7
’ 64.7
/
16.1
I IS86-252 N
1 1279.4
I
61.2 1 1015.5
1
63.2
1
15.5
1 132.5
!
i --
I
l
-
l
-.-_
l
i
I
I
j Mean ( x >
1485.2
63.9
1165.4
66.2
16
213.& -7
i
C.V. (%)
11.6
2.3
13.5
3.6
3.3
38.3
1
; LSD 0~5
171.3
1.4
127.5
1.9
0.4
118.4
/
-.-
_----I_-~
_- I
- 8
Table 2 : Advanced yield tria1 II.
-
-
-
/ .._-.___-_.. T.--.
- - - -
-
-
T------------
--- --
/
Bambey-Thilmakha
/Bambey-Thilmakl
- -~ --l--.-I
Lines
j
Louga
/
Ndiémane
, Ndiol
i
-
----.---I---p
I-----
I
I
l
Seed
d.to Mat! Seed
!d.to I
d.to Mat
Dry
1 Seed
I
/
I i
i ikghd j
: Matter
l
kgha)
I
t kg/tW )
f-.- ____.__ -_ -
..-.--- - - -
- ’ -<--- ’
j
58-57
I 1394.2
64.6
1 1083.7 /
67.1
65.2
3850 / 167.5
/
I IS86-237N
1350.9
60.2
I 1025.6 1
61.;
1 13.9
I 1250
59.5
2050 I 180.5 I
I
’
1%6-279N !I 1299.1
61.4
j
986.9 /
62.1
1 16.8
j 2081.9
58.5
2750 j 277.5
j
Mougne
I 1251.1
62.5
/ 984.1 I 64.1
I 14.4 i 1110.5
59.5
3408 l 445
I
[ .
/
1586-286N l 1248.9 j
59.7
/
965.9 i
61.1
1 13.6
j 1550 /
60.2
2150 j 337.5
/
/ IS86- 299N I 1239.5 I
62.1
/
943
I
63.;
I 17.6
I 1218.61
56.9
3313.7 ( 230
!
j TVX 3236
1214.9 /
67.6
926.6
69.;
1
/
/
1 li.3
/ 1450 j
6 4
4350 / 323
I
/
IS86-259N
1205.6 I 63.2
937.6 1 65
I 20.9
/ 1594.31
58.3
3430.9) 166.9
/
IS86-93 N
l129.6 /
65.1
/
919.7
65..
j 20
j 1007.8, '
60
3008.1; 302.5
;
IS86-76 N I 1094.6 I
64.5
833.9 i
65.1
/ 14
1
778.41
60.5
3276.81 412.5
j
/
IS86-241N 1 1057.2 j
61.5
858.9 1
64.1
I 15.9
j 1000
/
60
3175
I
IS86-253N
11033
1 62.2
792.8 I 65
1 13.5
1 1500
58.7
2400
295
1
j IS86-185N
1.009.6 /
57.6
785.6 j
60.3
/ 10.6
1 il75
56.5
3025
382.5
/
"
1 IS86-217N
1007.7 I
55.4
813.5 ! 57.5
I 13.5
I 1500
55.2
2900
315
I
j IS86-114N / 1006.5 j 58 !
779.3 j 60.5
j 12.3
i 1200
57.7
185
I
3375
,
/ IS86-2 N I
945.9
57.4
768.1 1 59.7
I 14.6
i 1175
56.2
4025
172.5
I
j IS86-168N/
826.9
58.4
/
734.6
60.3
j 14.8
1
886.6
59.6
2821.3
237.5
j
l IS86-224N/ 633.9
57.1
1
472.6
58.7
i 13.8
i
375
l
57
1725
1 110
l
I--.- --!--
1
- - - -
I
!-
1
l
i ..-~- --
I
-I---
) Mean (x)
1108.3
61
867.3
62.9
14.6
1392.3
66.5
3439.6
259
I
/
/ C.V. s
15.2
3.4
17.9
3.1
3.9
24.9
1.9
26.9
54.6 /
/ LSD 0.05
167.3
2
125.9
1.6
0.5
491.5
0.8
1321.4
200.8 /
- 9-
T a b l e 3 : Advanced yield tria1 III.
) Bambey - Thilmakha
I
fi
Bambey - Thilmakha - Louga
I
l
l
Lines
1 Seed
!CiMatter/
Seed
1 d. to Mat.
I
1100 seed
1 ( Wha) 1
(kg/hd
/
1 weight (g)
- - -
_--
-~-_
I-
I-
---+:
;
IS86-275 N /
1332
I
60.2
1196.3
j
61.6
1
16.6
!
i 58-57
I
1302.2
1
63.9
1105.6
(
65.4
I
12.1
/ TVX 3236
/
1281.9
j
64.5
1033.8
/
66
11.6
Mougne
I
1167.4
l
62.2
1019.9
1
63.8
14.9
l
IS86-63 N
j
1109.6
/
6 3
918.9
,
6 5
19.1
(
IS86-219 N
I
1080.9
I
56.1
845.6
1
58.9
i
13
l
IS86-248 N
l
1075.3
l
59.5
900.2
1
60.7
1
14.4
/
IS86- 140 N
I
1036.2
/
59
965.8
60*4
12.3
l
1 IS86-191 N
/
1015.9
l
52.9
889.8
1
l
56.1
12.7
1
I IS86-174 N
I
984.1
1
54.5
876.9
i
57.7
1
13.2
1
/ IS86-218 N
I
9 3 3 . 2
/
5 3 . 9
780.4
/
56.5
/
12.8
j
I IS86-48 N
1
914.8
1
56.9
/ IS86-36 N
;
906.6
;
57.7
709.9
1
59.1
I
14*6
l
1
733.6
1
59.4
12.6
/
""
I Bambey *l
I
726.6
1
58.9
626.1
1
61*4
I
18.1
1 IS86-121 N
l
703.9
1
56.6
527.6
I
59.4
j
11.4
1
i
I IS86-1'70 N
1
619.6
I
55.2
496.4
1
58.7
I
14.1
I
/
I
Mean
(X)
1011.9
58.4
851.7
60.6
13.9
1
,
C.V. %
19.6
2.8
25.2
2.5
3.7
l
LSD
0.05
196.7
1.6
173.5
1.2
0.4
i
::.1.:
- - - -
REFERENCES
Bal, A.B., 1987 - Rapport d'activités 1
I. ISRA-CNRA - Bambey.
Esunting, A.H., 1985 - What is this thin
:alled drought, workshop on drought
of the bean-cowpea CRSP, Durai
I, Mexico, 26-28 Août 85.
Cissé, ND.,- 1985a - L'amélioration du I ;bé au Sénégal. Dans travaux et docu-
ments du CILSS no 3, 4-8.
Cissé, ND., - 1985b - Project CRSP niébc
Rapport annuel 1984. ISRA-CNRA - Bambey.
Cissé, ND., - 1986 - Amélioration du n-ii
. Projet CRSP-niébé - Rapport annuel
1985 - ISRA-CNRA - Bambey.
Cissé, ND., 1987 - Amélioration du niébr
Projet CRSP - Rapport annuel 1986.
ISRA-CNRA Bambey.
Cissé, ND., 1988 - Amélioration du niébi
irojet CRSP-niébé - Rapport annuel 198;' -
ISRA-CNRA Bambey.
Dancette, C., - 1984 - La résistance du
ébé à la sécheresse sous climat soudano-
sahélien. Etudes techniques dl
:NRA no 10.
Cinlay, K.w. & Wilkinson, G.N., 1963 -
analysis of adaptation in a plant
breeding program. Aust. J. Ag
Res., 1963, 14.
?
Gahukar, 1986 - CILSS project annual rei
t.
Gaikwad, D.G., 1987 - Annual report on I rpea phytopathology 1986. ISRA-CNRA
Bambey.
Gaikwad,, D.G., 1988 - Annual report on ' rpea pathology 1987.
Mersch, 1985 - Operation niébé 1985 - DI
igation de la CEE - Dakar.
Patel , P.N., 1984, 1984, 1985, 86, 88 -
Ian-cowpea CRSP Trip report. UCR
Riverside Ca.
Sene, D., 1971 - L'amélioration du niébl
u CNRA de Bambey de 1959 à 1969.
L'agronomie tropicale no 26.
Simmonds, N.w., 1979 - Principles of cri
improvement.
Longman 1979. pp. 408.
Singh, S'.R. ; Jackai, L.E.N., 1985. Ins
: pests of cowpeas in Africa : Their
life cycle, Economie importan'
and potential control. In cowpea research,
production and utilization. Ji
I
wilev 1985.