4 II“! .’ , SYNTHESLS OF' THE ZSEARCH ...
4
II“!
.’ ,
SYNTHESLS OF' THE
ZSEARCH
ACTTVITIES ON COWPEA Pi ~OLOGY 1388
BY
D.G. G4IKWAD
Screenir.g agnir.st majc-)r di.s s e : ; iv‘as t,he mair, resear,‘:h a ‘tivi t.,; dcr*:ir:g
19~38. This included a disease nursery
scr,eenir,g f o r v i r u s re::istnr:ce
i r : the f’ield
as well as in the screer. hocse and SC.
er,i r:~: f’ot. bac terial bl 1 .:ht :*esisl;:ir?cc? ir:
the screer. hoüse. Virüs t:ro.r.smi::sion I sd-i i>s , hoth throcgh set 1 a r : i by the ir:,sects,
xf?r*e contir,cecI dürir.rr t.!:is year :?lso.
im i / ;iJ*ll’ :i s t a t i s t i c a l J; 1;: d oüt. expi!rbi.-
1’
mcr:t f o r estimation. o f yield 10s:: d u e
o ‘: Y
I~L:S vas cor,dnc ted. Jheirl i cal L;E~~O! oY
asliy stem blight was a p.ew rcsear-sch a~
ivi t,v ir;i tiated in 198’ . Hi,:hligh;.s of the
reaults of a11 these experiments are I nm;r r#ised in t,he followi ng pzragraphs .
1. Resistance screecing f o : najor di.seases :
1.1. Screening for Viri
resistance :
A field tria1 coc,sistir:g of
!3 breeding lines from advanced generations
ar.f:l 4 varieties was conducted at Djibt 3r !‘or evaluating their vir,.is res-istanlze.
Ail t:he 5 advanced generation entries rom the cross 58-57 x YY 8~1~ 1137 wAic::?
we??e repeated 4 times in a11 the sub i ia 1s developed virus irfect ion. Iiowever ,
I:!i id type as well as less vires infeci III? was developed on 2 i ines viz., 2’75 N
ar.d 2$33 N . Out o f o t h e r 4 3 F,~~~~,.~(!.‘.~,~ 1: 3.53,
-
22 ozerc) f r e e f r o m \\‘ir~s. Amongst t11e
va:‘ieties B 21 and TVx 3236 were resis IRIS wtli le 58-57 and Nd i ambo::r weI*cp s:xc:eptit)le
Al1 these entries togetherw: 1 i’ew more entries were screened in the
scree:n house under artificial ir.ocula1 3n. Ozt of’ 65 entries , 37 breedir.g lines
34S2246-4 ar.d CB
showed resistar.t
and 4 varieties viz. ,/reaction.
B 21 TVX~~ % 3
‘5 r Yougne and Ndiam2our wcre szsccpti ble . l’he
foîlowing 15 brceb kg lines were obs,el
sd t o b e f’ree o f v i r u s i n che fieid as well
as in thr screen house test. 365 N, 3t
N, ‘369 N, 371 N , 405 N, ‘+08 N: 411 N,
414 N, 415 N, 416 N, 421 N, 422 N, 42’
J > !‘30 N and 432 N.
1.2.Screenirg
f o r b a c t e r i a l
light resistance :
A set of 65 entries compris
g of 58 breeding lines from advar.ced yield
trial:s and 7 varieties were screened
ttic screer: house by aITtif j cial inoc.dlation.
l’he results indicated that 42 breedin; lir:es and 3 varieties iiz. , Mougce, TVx3236
a& T.‘I’ 84 S 2246-4 are resistant to ~?;(?y i.a:L t)light, Racter ; 3.1
Llight was seep
or! 58,-57 f o r t h e f i r s t t i m e . Out o f 1’ breeding lines which were f’ound resistant
t o vi:rus, t h e fol1.n~:‘~’ 1 3 line8 w e r e
lso found to be resistnct
t:o bacterial blight.
365 N, 368 N, 36~1 i:, : 1,; N, 408 N > ‘il
N, hl,4 N,
415 N, 416 N, 422 N, 429 N, 430 N
nr. d “32 N.
t ; sir?qLe i)lar:i selections of 2’75 N ar.ti 283 N
ag;kir:r;t tacter-ial b l i g h t i n the scrc.er: ho.use
by artificial inoculation. From thit scrrcenir.;: 9 CI:’ 275 N and 2of 283 fi bacterisl
!.)l ight, resistant plants were obtaint j which wi i l tl.1 used i n tlie cyossing program.
1 . 3 . Disease riarsery :
Out of’ 120 entrlies which ( 2mpr#ised o f ‘i!l v a r i e t i e s and 4 breedlng lines,
‘16 varieties and 11 breeding lines 1 ?re observed t:) be virus free. Some :,f alite
‘bre,eding lines (275 N and. 2 8 3 N) shc ded mixture of’ resistant and susceptible
plants. Virus resistant plants were ;elected f’rom ‘.hese lines f o r further t e s t i n g .
Hacterial blight development in the lisease nurser:: was poor. Only 7 entries
developed bacterial blight infectior mostly on the Stern. Macrophomina bl igh-t was
very heavy in the disease nursery WL i.ch might bave suppressed the develobment of
other diseases. Only 19 entries were Pound to be resistant to Macrophomina hlight;.
Cercospora infection wa:; developed 1 te. 2’7 entries were rated as suscep: ih:!.e
whi-le 9 were observed to be almos t f 3e. Choar:epho:3a pod rot and web blight were
not seen this year in thc disease nu sej’y. Twt.1 ent:‘ies viz., 78-36 and 5’:-20 were
f o u c d r e s i s t a n t t o a11 11 d i s e a s e s . ~
II. Virus transmission stuc ies :
2.1. Transmission thrc
-
-
Jgh seed :
-
-
The tria]. was conducted nt 2 locations viz., Bambey and Djibelor. ‘There
were three treatments in the tria1 cc ndccted at Banbey viz., infected seed,
healthy seed and farmers ’ seed. InPeI ted yeed showed 5.04% virus incidenc*e while
1. .OG% virus infected plants were seer ir. heal thy seed I Farmers’ seed exhibited
2.46% virus contamination. The germi.1 stion percentage in infected seed ar.d farmers’
seecl was much low than healthy seed . In the D,j ibelor tria1 where only f’armers’
Seed of a local variety was üsed, on an nverage 5.‘!9% v i r u s i n f e c t i o n occurred
through seed.
2.2. Transmission by : nsects :
The tria1 at Bambey for vii JS transmission through seed was further
cont;ined to see the effect of occurr nce of aphids on the spread of virus. The
observations recorded 42 days after ~owi.ng revealed that the virus inci.dence was
i.ncreased from ‘; .04X ~:n 2.3 .!+4% in thl infected seed while it was i.ncreased from
1 .Of\\% to 17.41% in the hen:Lthy seed. Farmers ’ seed also showed increase I.R virus
incidence from 2.46% to 19.08%. Ail.
hese increases were due to transmissIon of
virus by aphids.
I-II. Estïmatior. o f
- l o s s i n
zld ti:;e t o vires :
The resul.ts of a statisticz y l.aici oEt tria1 cor.duc: ed at Bnrnbeh
revealed that there was significant r
JC tirlr: in iield o f ;:::prc!tected plots (!Je
to mcre virzs incidence. The loss was
;timated te be 30% ( 343 Kg/ha) in this. triai.
The reszlts of correlatioc
stcdies be
3er +; seas’.’ ir.ci denc.6: a::d t h e y i e l d fkrther
showed that with the ir:crease in the
rcs i !:cider:ce there wûs sigr,if icant ri:dXc-
tion in the yield.
IV. Chemical control of ash
Stern hlight :
Ashy stem blight caused due
3 blacrophon:ina phaseolii:a was a serious
-
disease on cowpea in 1987. Hence an e
2rimer.t was initiated this year for i!,s
cor.trol with 4 seed dressers at diff
:nt doses. The resclts of the experiment
revealed that seed treatment. with gra
Y gives sarisfactory set,? germination. It
is also effective against Macrophomir
infection in the early trop growth stage.
However ,no c+j-i!ical was f’oLLr.d effecti
uEder high disease pressure in the later
stage. C:her? t h e s e chemicals: were test
in vi tro i.r. the labora: ory, granox proved
its superiority over a11 other treatn:
ts.
V. Survey of cowpea disease
Disease s i t u a t i o n duricg l/
trop season was serio. in respect of
mosaîc diseases. A very high vires ir
!ier,ce was observed on 5S-57 in ail the
cowpea areas. Howeves, the incidence
otheï diseases was much less as compared
to previous years. As usual bacterial
light was Lhe main disease on B 21. Some
of the B 21 fields were 1:adly affecte
For ‘;he f‘Irst time bacterial blight was
seen on 58-57. Macrophomina blight, w
:h ha:: very serious duri ng 1987 season, was
seen s p o r a d i c a l l y i n some o f the f i e l
. However,
it was quite serious in the
Pathology Field at Bambey q Incidence
weh ?Jight, a s well a s ::hoanephora pod r o t
was very low. Cercospora leaf’ spot, t
lgh serious on some of r.he entries, occüred
late. Brown blotch was seen on CH5 at
3mbey. f3acterial ?ustEle was comparatively
more, it was seer. in some of the mini
t triais mostly on CBg, Ndiambour and t321.
This year striga was seen at 4 locati 3. :ts incidence was quite serious at Ndatt
Fa:Ll, Sine Dieng and Keur Boumi.
VI. Summary :
Out of 65 entries tested aga nst. ~‘~.rus the following 15 breetiing 1ir:es
were observed to be virus
t h c i’ield ris well. a : ; i n the screer, llouee
test. 365 N, 368 Y, 369 N,
, 408 N, 411 N, 414 N, 115 N, 416 N. 421N
422 N, 429 N,
430 N and 432 N.
Amor.gs t the l;ari.er. *es B 2 1 ,
VX 3236 a n d 1’1’ 8 4 .S 2 2 4 6 - 4 were rcsistant
to v ir..s
Y .
Oüt o f
15 breedinrf lir.esfo
d resi:: / ant to v.irs,s, the fol lowing 13 1 in:!:;
were also r e s i s t a n t t.0 bactt,:*ial hl ig
. ‘165 tv, 368 N, 369 N, 405, 408 N, 911 N,
411: N, ‘115 N, 416 N, 422 N, 'i29 N, ‘+3
N and 4 32 N .
A disense nurser~y of i20 e n
i e s coii!:;rising o f '[9 v a r i e t i e s and !il irreeti i::g
I.ir:es yielded 1 9 entries :‘e::;st.ant to
acrophc>. lina bl.igh t and 57 res is tant to
1”. -; I”,J s unlier a heavy disease : ~~os:;u-‘~~
l)tlt,il t II~ tfisease:. . Incidence of otller
diseases vas mirzor. Two c::t!,ies viz. ,
8-36 ar:ri 59-20 were found resistant to a11
4 diseases.
In the virus transmission s dies 5.04% transmission through seed was
recorded in the infected seecl while i
was 1 .Oi,% in the healthy seed . The i’armers ’
seed shnued 2.46% and 5.79% virus con
rninatioi-. at Bambey and Dj ibelor respect ively .
Subsquently there was substantial inc
ase in t;he virus incidence at Bambey due
t o aphids.
The resalts !,f thc experime
o n es: <mation o f yield loss d.ue tc: virüs
rcvealed t h a t t h e r e w a s 30% 343 K g /
) yieici .Loss due to vi-rus.
In a chemical COI?Y.i?Ol exper
ent agr-inst ashy stem blight granox was found
superior for obtaining good +rminati
. But !.i:der the heavy disease pressure ai
later stage no chem-ical was :‘ound eff
tive .
During survey o f (.owpea d i s
ses: movai.c virus was found to be kide apread
and quitc severe in some of ;;he f i e l d
particclarly of 58-57. Ashy stem blight, was
s p c r a d i c and much less than y.987 seas
. Bacterial biight was severe in some of’ t.he
B 21 fieI.ds> F o r the f i r s t tirne bacte
a1 blight was seen on 58-57. Incidence of
other diseases was minor. St-riga was
en at 4 1 ocations viz. Ndatt Fal.1, S i n e Dieng,
keur Eoumi and Bambey.
II“!
.’ ,
SYNTHESLS OF' THE
ZSEARCH
ACTTVITIES ON COWPEA Pi ~OLOGY 1388
BY
D.G. G4IKWAD
Screenir.g agnir.st majc-)r di.s s e : ; iv‘as t,he mair, resear,‘:h a ‘tivi t.,; dcr*:ir:g
19~38. This included a disease nursery
scr,eenir,g f o r v i r u s re::istnr:ce
i r : the f’ield
as well as in the screer. hocse and SC.
er,i r:~: f’ot. bac terial bl 1 .:ht :*esisl;:ir?cc? ir:
the screer. hoüse. Virüs t:ro.r.smi::sion I sd-i i>s , hoth throcgh set 1 a r : i by the ir:,sects,
xf?r*e contir,cecI dürir.rr t.!:is year :?lso.
im i / ;iJ*ll’ :i s t a t i s t i c a l J; 1;: d oüt. expi!rbi.-
1’
mcr:t f o r estimation. o f yield 10s:: d u e
o ‘: Y
I~L:S vas cor,dnc ted. Jheirl i cal L;E~~O! oY
asliy stem blight was a p.ew rcsear-sch a~
ivi t,v ir;i tiated in 198’ . Hi,:hligh;.s of the
reaults of a11 these experiments are I nm;r r#ised in t,he followi ng pzragraphs .
1. Resistance screecing f o : najor di.seases :
1.1. Screening for Viri
resistance :
A field tria1 coc,sistir:g of
!3 breeding lines from advanced generations
ar.f:l 4 varieties was conducted at Djibt 3r !‘or evaluating their vir,.is res-istanlze.
Ail t:he 5 advanced generation entries rom the cross 58-57 x YY 8~1~ 1137 wAic::?
we??e repeated 4 times in a11 the sub i ia 1s developed virus irfect ion. Iiowever ,
I:!i id type as well as less vires infeci III? was developed on 2 i ines viz., 2’75 N
ar.d 2$33 N . Out o f o t h e r 4 3 F,~~~~,.~(!.‘.~,~ 1: 3.53,
-
22 ozerc) f r e e f r o m \\‘ir~s. Amongst t11e
va:‘ieties B 21 and TVx 3236 were resis IRIS wtli le 58-57 and Nd i ambo::r weI*cp s:xc:eptit)le
Al1 these entries togetherw: 1 i’ew more entries were screened in the
scree:n house under artificial ir.ocula1 3n. Ozt of’ 65 entries , 37 breedir.g lines
34S2246-4 ar.d CB
showed resistar.t
and 4 varieties viz. ,/reaction.
B 21 TVX~~ % 3
‘5 r Yougne and Ndiam2our wcre szsccpti ble . l’he
foîlowing 15 brceb kg lines were obs,el
sd t o b e f’ree o f v i r u s i n che fieid as well
as in thr screen house test. 365 N, 3t
N, ‘369 N, 371 N , 405 N, ‘+08 N: 411 N,
414 N, 415 N, 416 N, 421 N, 422 N, 42’
J > !‘30 N and 432 N.
1.2.Screenirg
f o r b a c t e r i a l
light resistance :
A set of 65 entries compris
g of 58 breeding lines from advar.ced yield
trial:s and 7 varieties were screened
ttic screer: house by aITtif j cial inoc.dlation.
l’he results indicated that 42 breedin; lir:es and 3 varieties iiz. , Mougce, TVx3236
a& T.‘I’ 84 S 2246-4 are resistant to ~?;(?y i.a:L t)light, Racter ; 3.1
Llight was seep
or! 58,-57 f o r t h e f i r s t t i m e . Out o f 1’ breeding lines which were f’ound resistant
t o vi:rus, t h e fol1.n~:‘~’ 1 3 line8 w e r e
lso found to be resistnct
t:o bacterial blight.
365 N, 368 N, 36~1 i:, : 1,; N, 408 N > ‘il
N, hl,4 N,
415 N, 416 N, 422 N, 429 N, 430 N
nr. d “32 N.
t ; sir?qLe i)lar:i selections of 2’75 N ar.ti 283 N
ag;kir:r;t tacter-ial b l i g h t i n the scrc.er: ho.use
by artificial inoculation. From thit scrrcenir.;: 9 CI:’ 275 N and 2of 283 fi bacterisl
!.)l ight, resistant plants were obtaint j which wi i l tl.1 used i n tlie cyossing program.
1 . 3 . Disease riarsery :
Out of’ 120 entrlies which ( 2mpr#ised o f ‘i!l v a r i e t i e s and 4 breedlng lines,
‘16 varieties and 11 breeding lines 1 ?re observed t:) be virus free. Some :,f alite
‘bre,eding lines (275 N and. 2 8 3 N) shc ded mixture of’ resistant and susceptible
plants. Virus resistant plants were ;elected f’rom ‘.hese lines f o r further t e s t i n g .
Hacterial blight development in the lisease nurser:: was poor. Only 7 entries
developed bacterial blight infectior mostly on the Stern. Macrophomina bl igh-t was
very heavy in the disease nursery WL i.ch might bave suppressed the develobment of
other diseases. Only 19 entries were Pound to be resistant to Macrophomina hlight;.
Cercospora infection wa:; developed 1 te. 2’7 entries were rated as suscep: ih:!.e
whi-le 9 were observed to be almos t f 3e. Choar:epho:3a pod rot and web blight were
not seen this year in thc disease nu sej’y. Twt.1 ent:‘ies viz., 78-36 and 5’:-20 were
f o u c d r e s i s t a n t t o a11 11 d i s e a s e s . ~
II. Virus transmission stuc ies :
2.1. Transmission thrc
-
-
Jgh seed :
-
-
The tria]. was conducted nt 2 locations viz., Bambey and Djibelor. ‘There
were three treatments in the tria1 cc ndccted at Banbey viz., infected seed,
healthy seed and farmers ’ seed. InPeI ted yeed showed 5.04% virus incidenc*e while
1. .OG% virus infected plants were seer ir. heal thy seed I Farmers’ seed exhibited
2.46% virus contamination. The germi.1 stion percentage in infected seed ar.d farmers’
seecl was much low than healthy seed . In the D,j ibelor tria1 where only f’armers’
Seed of a local variety was üsed, on an nverage 5.‘!9% v i r u s i n f e c t i o n occurred
through seed.
2.2. Transmission by : nsects :
The tria1 at Bambey for vii JS transmission through seed was further
cont;ined to see the effect of occurr nce of aphids on the spread of virus. The
observations recorded 42 days after ~owi.ng revealed that the virus inci.dence was
i.ncreased from ‘; .04X ~:n 2.3 .!+4% in thl infected seed while it was i.ncreased from
1 .Of\\% to 17.41% in the hen:Lthy seed. Farmers ’ seed also showed increase I.R virus
incidence from 2.46% to 19.08%. Ail.
hese increases were due to transmissIon of
virus by aphids.
I-II. Estïmatior. o f
- l o s s i n
zld ti:;e t o vires :
The resul.ts of a statisticz y l.aici oEt tria1 cor.duc: ed at Bnrnbeh
revealed that there was significant r
JC tirlr: in iield o f ;:::prc!tected plots (!Je
to mcre virzs incidence. The loss was
;timated te be 30% ( 343 Kg/ha) in this. triai.
The reszlts of correlatioc
stcdies be
3er +; seas’.’ ir.ci denc.6: a::d t h e y i e l d fkrther
showed that with the ir:crease in the
rcs i !:cider:ce there wûs sigr,if icant ri:dXc-
tion in the yield.
IV. Chemical control of ash
Stern hlight :
Ashy stem blight caused due
3 blacrophon:ina phaseolii:a was a serious
-
disease on cowpea in 1987. Hence an e
2rimer.t was initiated this year for i!,s
cor.trol with 4 seed dressers at diff
:nt doses. The resclts of the experiment
revealed that seed treatment. with gra
Y gives sarisfactory set,? germination. It
is also effective against Macrophomir
infection in the early trop growth stage.
However ,no c+j-i!ical was f’oLLr.d effecti
uEder high disease pressure in the later
stage. C:her? t h e s e chemicals: were test
in vi tro i.r. the labora: ory, granox proved
its superiority over a11 other treatn:
ts.
V. Survey of cowpea disease
Disease s i t u a t i o n duricg l/
trop season was serio. in respect of
mosaîc diseases. A very high vires ir
!ier,ce was observed on 5S-57 in ail the
cowpea areas. Howeves, the incidence
otheï diseases was much less as compared
to previous years. As usual bacterial
light was Lhe main disease on B 21. Some
of the B 21 fields were 1:adly affecte
For ‘;he f‘Irst time bacterial blight was
seen on 58-57. Macrophomina blight, w
:h ha:: very serious duri ng 1987 season, was
seen s p o r a d i c a l l y i n some o f the f i e l
. However,
it was quite serious in the
Pathology Field at Bambey q Incidence
weh ?Jight, a s well a s ::hoanephora pod r o t
was very low. Cercospora leaf’ spot, t
lgh serious on some of r.he entries, occüred
late. Brown blotch was seen on CH5 at
3mbey. f3acterial ?ustEle was comparatively
more, it was seer. in some of the mini
t triais mostly on CBg, Ndiambour and t321.
This year striga was seen at 4 locati 3. :ts incidence was quite serious at Ndatt
Fa:Ll, Sine Dieng and Keur Boumi.
VI. Summary :
Out of 65 entries tested aga nst. ~‘~.rus the following 15 breetiing 1ir:es
were observed to be virus
t h c i’ield ris well. a : ; i n the screer, llouee
test. 365 N, 368 Y, 369 N,
, 408 N, 411 N, 414 N, 115 N, 416 N. 421N
422 N, 429 N,
430 N and 432 N.
Amor.gs t the l;ari.er. *es B 2 1 ,
VX 3236 a n d 1’1’ 8 4 .S 2 2 4 6 - 4 were rcsistant
to v ir..s
Y .
Oüt o f
15 breedinrf lir.esfo
d resi:: / ant to v.irs,s, the fol lowing 13 1 in:!:;
were also r e s i s t a n t t.0 bactt,:*ial hl ig
. ‘165 tv, 368 N, 369 N, 405, 408 N, 911 N,
411: N, ‘115 N, 416 N, 422 N, 'i29 N, ‘+3
N and 4 32 N .
A disense nurser~y of i20 e n
i e s coii!:;rising o f '[9 v a r i e t i e s and !il irreeti i::g
I.ir:es yielded 1 9 entries :‘e::;st.ant to
acrophc>. lina bl.igh t and 57 res is tant to
1”. -; I”,J s unlier a heavy disease : ~~os:;u-‘~~
l)tlt,il t II~ tfisease:. . Incidence of otller
diseases vas mirzor. Two c::t!,ies viz. ,
8-36 ar:ri 59-20 were found resistant to a11
4 diseases.
In the virus transmission s dies 5.04% transmission through seed was
recorded in the infected seecl while i
was 1 .Oi,% in the healthy seed . The i’armers ’
seed shnued 2.46% and 5.79% virus con
rninatioi-. at Bambey and Dj ibelor respect ively .
Subsquently there was substantial inc
ase in t;he virus incidence at Bambey due
t o aphids.
The resalts !,f thc experime
o n es: <mation o f yield loss d.ue tc: virüs
rcvealed t h a t t h e r e w a s 30% 343 K g /
) yieici .Loss due to vi-rus.
In a chemical COI?Y.i?Ol exper
ent agr-inst ashy stem blight granox was found
superior for obtaining good +rminati
. But !.i:der the heavy disease pressure ai
later stage no chem-ical was :‘ound eff
tive .
During survey o f (.owpea d i s
ses: movai.c virus was found to be kide apread
and quitc severe in some of ;;he f i e l d
particclarly of 58-57. Ashy stem blight, was
s p c r a d i c and much less than y.987 seas
. Bacterial biight was severe in some of’ t.he
B 21 fieI.ds> F o r the f i r s t tirne bacte
a1 blight was seen on 58-57. Incidence of
other diseases was minor. St-riga was
en at 4 1 ocations viz. Ndatt Fal.1, S i n e Dieng,
keur Eoumi and Bambey.