Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
AENSI Jou nals
Ad ances in En i onmen al Biology
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Ame ican-Eu asian Ne wo k o Scien i ic In o ma ion (AENSI Publica ion).
Cowpea (Vigna unguicula a) and bac e ial inocula ion:
A plausible componen s o an in eg a ed managemen
s a egy o he oo pa asi ic weed S iga
he mon hica on so ghum
1Es a A Mahmoud, 2Aisha A. M. Rezig, 3Mohammed M. Hassan, 3Randa H. Elslahi, 3Magdoline
M. Ahmed, 3Rani E. Abike , 4RashidaM.A. Abusin, 3Migdam E. Abdel Gani, 3Abdel Gaba E.T.
Babike
1Sudan Academy o Sciences (SAS).
2Sudan Uni e si y o Science and Technology, College o Ag icul u al S udies, Sudan.
3En i onmen and Na u al Resou ces and Dese i ica ion Resea ch Ins i u e, Na ional Cen e o Resea ch, Kha oum, Sudan.
4Bah i Uni e si y, College o Ag icul u e, Pes s and Plan Heal h, Kha oum, Sudan.
Add ess Fo Co espondence:
Mohammed M. Hassan, En i onmen and Na u al Resou ces and Dese i ica ion Resea ch Ins i u e, Na ional Cen e o Resea ch,
Kha oum, Sudan.
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Recei ed 22 May 2016; Accep ed 18 July 2016; A ailable online 8 Augus 2016
ABSTRACT Two se s o g eenhouse expe imen s we e conduc ed o in es iga e he e ec s o i) so ghum in e c opping wi h cowpea geno ypes and
seeds le el o S iga on S iga incidence on so ghum Wad Ahmed, ii) in e c opping o cowpea, bac e ial s ains and ino ganic phospho us
on S iga he mon hica pa asi ism and so ghum g ow h. T ea men s we e a anged in a andomized comple e block design wi h ou
eplica ions. In he i s g eenhouse expe imen , i espec i e o in e c opping, S iga eme gence p og essi ely inc eased wi h seed bank size.
In e c opping, signi ican ly, educed S iga eme gence and d y weigh . Base on he o e all means o S iga eme gence, in e c opping o
B301 and T100K-901-6 cowpea geno ypes wi h so ghum educed S iga eme gence by 95- 45% and 96-52% a 1 – 16mg/po o S iga seed
bank, espec i ely as compa ed o con ol. A consis en p og essi e decline in so ghum heigh , lea a ea and d y weigh was e iden in sole
so ghum c op wi h inc easing S iga seed bank size. , In e c opped so ghum, in a iably, imp o ed so ghum g ow h han sole so ghum. In
he second expe imen , in e c opping wi h cowpea, inocula ed wi h Rhizobium leguminosa um alone o in combina ion wi h phospho us,
delayed and ep essed S iga eme gence, signi ican ly in compa ison o sole so ghumwi h a educ ion anging be ween 98 and 92%,
espec i ely. Howe e , signi ican inc emen s o lea a ea we e only a ained when so ghum in e c opped wi h Rhizobium inocula ed
cowpea, alone o in combina ion wi h phospho us a 92 kg ha-1 by 56 and 50%, espec i ely. In e c opping wi h cowpea inocula ed wi h
Rhizobium alone o in combina ion wi h phospho us a 46 kg ha-1inc eased so ghum d y weigh signi ican ly as compa ed wi h he
co esponding con ol. In conclusion, cowpea geno ypes inocula ed wi h he bac e ial combina ion, in a iably achie ed he highes
educ ions in S iga eme gence as well as he highes inc ease in he measu ed so ghum g ow h a ibu es.
KEYWORDS: cowpea, so ghum, bac e ial s ains, phospho us, incidence, S iga seeds size
INTRODUCTION
In e c opping is a po en ial bene icial sys em o c op p oduc ion. I o e s a be e u iliza ion o na u al and
labo esou ces, p o ides sa e gua ds agains ailu e o single c op, gi es g ea e yield and e u n pe uni a ea,
and minimizes he sp ead o pes s and diseases [1].Phospho us is one o se e al elemen s which a ec ni ogen
2 Es a A Mahmoud e al, 2016
Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
ixa ion, and along wi h ni ogen, i is a p incipal yield-limi ing nu ien in ag icul u al p oduc ion [2]. The
applica ion o phospho us could hus, enhance maximum exploi a ion o he ad an ages o biological ni ogen
ixa ion (BNF) mechanism by legumes. Hence, he use o g ain legumes in smallholde c opping sys ems is
being widely p omo ed and has ecei ed subs an ial a en ion ac oss A ica as an al e na i e s a egy o enhance
soil e ili y and imp o e g ain yields [3].
High illi e acy among a me s, lack o awa eness o he S iga li e cycle and he una oidable low c op
p oduc i i y a ising om he damage he pa asi e in lic s while sub e anean, makes a me s eluc an o accep
and/o adop pos -eme gence con ol measu es [4]. Deple ion o he soil seed bank o S iga by suicidal
ge mina ion, which in ol es ge mina ion o he seeds in absence o o away om he hos oo s, is a po en ial
con ol op ion and has been s ongly ad oca ed by se e al au ho s [5, 6]. Hence he e is a need o look o
simple echniques as componen s o an in eg a ed S iga con ol package which is adap able o he A ican
si ua ion. Legume o a ion ope a es h ough wo majo mechanisms, suicidal ge mina ion o S iga he mon hica
seeds in he soil and imp o emen o soil e ili y. Sibha u [7] obse ed ha S iga in es a ion dec eased wi h
inc easing o ganic ma e o he soil and ha o ganic ma e con en seemed o be he mos impo an ac o
which p ese ed he soil e ili y. Since soil mic obial biomass lou ishes be e in a medium ich in o ganic
ma e , o ganic o ino ganic soil amendmen s may inc ease soil supp essi eness o S iga he mon hica and also
imp o e soil condi ions o inc ease yield o subsequen ce eal. In his wo k, wo g eenhouse expe imen s we e
conduc ed o s udy he e ec s o in e c opping o selec ed cowpea geno ypes and S iga seed le el on S iga
pa asi ism and so ghum g ow h as well as he supp essi e e ec s o cowpea inocula ed wi h hizobia, BMP,
ino ganic phospho us each alone o in combina ion on S iga pa asi ism and so ghum g ow h.
MATERIALS AND METHODS
Seeds:
So ghum cul i a Wad Ahmed was ob ained om he Ag icul u al Resea ch Co po a ion, Sudan. Tow
cowpea geno ypes B301 and T100K-901-6we e ob ained om he In e na ional Ins i u e o T opical Ag icul u e
(IITA) Ibadan Nige ia. S iga he mon hica, seeds we e collec ed om so ghum in es ed ields.
Mic obial Bio- e ilize s:
The bac e ial s ains (Rhizobium leguminosa um and Bacillus mega he ium a . phospha icum (BMP))
(selec ed on basis o hei abili y o supp ess S. he mon hica ge mina ion.) we e ob ained om En i onmen and
Na u al Resou ces and Dese i ica ion Resea ch Ins i u e (ENRDRI), Na ional Cen e o Resea ch (NCR),
Kha oum, Sudan. Au ocla e s e ilized ( o 20 min a 15 ba s and 121 ⁰C o 20 min) yeas ex ac manni ol and
mea pep one b o h media we e inocula ed by Rhizobium leguminosa um (TAL 1399 and Bacillus mega he ium
a . phospha icum (BMP), espec i ely.
Gene al:
Two se s o g een- house expe imen s we e conduc ed a he College o Ag icul u al S udies (CAS), Sudan
Uni e si y o Science and Technology, In bo h expe imen s, unless o he wise men ioned, po s (36 cm i.d. and
32 cm in heigh ), pe o a ed a he bo om, we e illed wi h 7 kg sand mix (2:1) p epa ed by mixing soil
collec ed om CAS a m wi h i e sand. S. he mon hica seeds we e mixed wi h he op 10 cm o soil in each
po . So ghum Wad Ahmed seeds (5/po ) we e plan ed. Cowpea geno ypes B301 and T100K-901-6seeds (7/po )
we e plan ed as a companion c op. So ghum and cowpea seedlings we e hinned o 2 and 3, espec i ely, 7 days
a e eme gence. Sole so ghum, S iga in es ed and S iga ee so ghum in e c opped wi h cowpea we e
included as con ols o compa ison. All po s we e i iga ed a 2–3 days in e als h oughou he g owing pe iod.
Weeds o he han S. he mon hica we e emo ed by hand. Eme gen S iga plan s we e coun ed weekly s a ing
h ee weeks a e c op eme gence. S iga coun and so ghum heigh we e de e mined 30, 60 and 90 days a e
sowing (DAS). Lea a ea was es ima ed by mul iplying he leng h o he second lea om op by hal o
maximum wid h o he lea a 30, 60 and 90 DAS. A ha es , so ghum and S iga shoo s, each, we e cu a
g ound le el, ai -d ied and weighed.
Fi s expe imen , e ec s o in e c opping and le el o S iga seeds on S iga incidence and so ghum g ow h:
Soil was inocula ed wi h di e en le els o S iga seeds (0, 1, 2, 4, 8, 16 and 32mg/po ). So ghum seeds
(5/po ) we e plan ed a Ca. 2 cm. soil dep h. Cowpea B301 and T100K-901-6 seeds (7/po ) we e plan ed as a
companion c op. So ghum and cowpea geno ypes we e hinned as desc ibed abo e. S iga eme gence, so ghum
heigh s, lea a ea, so ghum and S iga d y weigh s we e measu ed as desc ibed abo e.
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Second expe imen , e ec s o in e c opping, bac e ial s ains and ino ganic e ilize on S iga incidence and
so ghum g ow h:
In he g een house expe imen in e c opping was in eg a ed wi h inocula ion o Rhizobium leguminosa um
TAL1399, phospho us solubilizing bac e ium (Bcillus mega he ium a phospha icum)as well as ino ganic
phospho us. Soil in es ed wi h S. he mon hica seeds, placed in plas ic po s, was sown wi hso ghum c . Wad
Ahmed and cowpea T100K-901-6 as desc ibed abo e. Cowpea seeds we e ei he inocula ed wi h Rhizobium
leguminosa um and B. mega he ium each alone o in combina ions wi h ino ganic e ilize . Aliquo s (15 ml
each)o each o he espec i e bac e ial suspensions ( (10-4 dilu ion) we e injec ed, wi hin he oo zone, a each
po . I iga ions we e ca ied ou e e y 2 days. Phospho us was applied a wo doses 46 kg ha-1 and92 kg ha-1,
immedia ely a e sowing. The expe imen was conduc ed in a RCBD wi h ou eplica ions. Da a o so ghum
lea chlo ophyll con en we e aken a 30, 45, 60 and 75 DAS by using a SPAD-502 Chlo ophyll Me e
(Minol a). Lea a ea was measu ed a 30, 45, 60 and 90 DAS. S iga eme gence, so ghum heigh , lea a ea and
shoo d y weigh o so ghum and S iga we e measu ed as desc ibed abo e.
Resul s:
G eenhouse expe imen s:
Fi s expe imen , e ec s o in e c opping and le el o S iga seeds on S iga incidence and so ghum g ow h
E ec s on S iga eme gence:
S iga eme gence, on so ghum, i espec i e o in e c opping, inc eased wi h ime and seed bank size. A 30
DAS, a e age S iga eme gence on sole so ghum a he lowes seed bank size was 3 plan s/po (Table1).
Inc easing S iga seed bank o 8 o 16 mg/po u he inc eased he pa asi e eme gence, albei no signi ican ly.
A he highes seed bank size (32mg/po ),S iga eme gence inc eased signi ican ly (Table 1).So ghum
in e c opped wi h cowpea B301 a he lowes seed bank size (0.3 plan / po ) displayed he lowes eme gence
(Table 1). Inc easing S iga seed bank size o 8 o mo e /po inc eased S iga eme gence signi ican ly in
compa ison o he lowes seed bank size. While, no any S iga eme gence was obse ed in so ghum
in e c opped wi h cowpea T100K901 a he lowes seed bank size. Howe e , a p og essi e, albei non-
signi ican inc ease in eme gence was obse ed up o a seed bank o 8 -16mg/po . Inc easing S iga seed bank
size o 32mg pe po , u he inc eased S iga eme gence by mo e han 4- old (Table 1).
A 60 DAS, S iga eme gence, i espec i e o seed bank size, showed conside able inc ease in compa ison
o ha eco ded a 30 DAS (Table 1). A 90 DAS, S iga eme gence showed a simila end. The a e age S iga
eme gence a he lowes and highes seed bank we e 13.3 and 25 plan s /po , espec i ely (Table 1). So ghum
in e c opped wi h cowpea B301 and T100K-901-6, inc easing S iga seed bank size o 16 and 32mg pe po
u he inc eased S iga eme gence by mo e han 2- o-4- old, espec i ely (Table 1). In he o e all mean, S iga
eme gence on so ghum in e c opped wi h cowpea B301 and T100K-901-6 geno ypes educed S iga eme gence
by 95- 45% and 96-52% a 1- 16mg/po , espec i ely as compa ed o he espec i e con ol.
D y weigh :
S iga d y weigh , i espec i e o in e c opping, p og essi ely inc eased wi h inc easing seed bank size
(Table 2). On sole so ghum, S iga d y weigh p og essi ely inc eased wi h seed bank size. Inc easing S iga
seed bank o 2 mg pe po inc eased S iga d y weigh by 74.9%. A S iga seed bank size o 4, 8, 16 and 32 mg
pe po he inc ease in S iga d y weigh was 133.7, 216, 257, and 275.7%, espec i ely in compa ison o he
lowes seed bank size (Table 2).S iga d y weigh on so ghum in e c opped wi h cowpea B301, albei
p og essi ely inc eased wi h seed bank (Table 4.9). Inc easing seeds bank size o 16 and 32 mg/po esul ed in
signi ican inc ease in d y weigh . S iga on so ghum in e c opped wi h cowpea T10K-901-6 displayed 19 g a
he lowes S iga seed bank size. A Fu he inc ease in seed bank o 8, 16 and 32 mg inc eased S iga d y weigh
by 52.6, 75.3 and 84%, espec i ely. Ac oss he seed bank size, sole so ghum sus ained he highes S iga d y
weigh ollowed by so ghum in e c opped wi h cowpea B301 and T100K-901-6 (Table 2).
E ec s on so ghum heigh :
So ghum heigh , i espec i e o in e c opping, displayed a p og essi e dec ease wi h S iga seed bank size
and inc eased wi h ime (Table3). In gene al, so ghum in e c opped wi h cowpea, i espec i e o he la e
geno ype o S iga seed bank size, displayed be e g ow h han sole so ghum. S iga ee so ghum, when
in e c opped wi h cowpea, i espec i e o geno ype o da e o obse a ion, displayed an inc ease in heigh o
27.7-64.5% in compa ison o he co esponding sole so ghum ea men . In sole so ghum a 30 DAS, S iga seed
bank a 1-8mg/po in lic ed insigni ican (5.1-20.9%) dec ease in heigh (Table 3). Inc easing S iga seed bank
size o 16 and 32 mg pe po educed so ghum heigh by 27.2and39.9%, espec i ely (Table 3). S iga seed bank
1 o 2 mg pe po educed so ghum heigh , albei no signi ican ly. Inc easing S iga seed bank size o 4 mg pe
po o mo e esul ed in signi ican educ ions in so ghum heigh . While, so ghum in e c opped wi h cowpea
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Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
T100K-901-6 did no show a signi ican educ ion in heigh a he lowes le el. The highes educ ion (36.5%)
was obse ed a he highes S iga seed bank (Table 3). A 60 DAS, educ ion in so ghum heigh ollowed mo e
o less simila ends. A 90 DAS, S iga seed bank size a 2 and 4 mg pe po educed so ghum heigh by 2 and
17.1%, espec i ely. Inc easing S iga seed bank size o 8 mg pe po o mo e, educed (24.5-36.7%) so ghum
heigh signi ican ly. In cowpea B301 and T100K-901-6, a seed bank o 4 mg /po o mo e esul ed in signi ican
educ ions. The highes educ ion (31.7 and 45%) was obse ed a he highes le els, espec i ely (Table 3).
Lea a ea:
So ghum lea a ea, i espec i e o in e c opping o ime, dec eased wi h inc easing S iga seed bank size
(Table 4).A 30 DAS, sole so ghum, in a iably, showed a p og essi e decline in lea a ea wi h S iga seed bank
size in compa ison o he S iga ee con ol (Table 4). The educ ions in lea a ea a S iga seed bank o 8, 16
and 32mg/po we e 47.8, 54.9, and 66.4%, espec i ely. So ghum in e c opped wi h cowpea geno ypes did no
show signi ican educ ion in lea a ea, i espec i e o he pa asi e seed bank size. A 60 DAS, he lea a ea o
sole so ghum showed a p og essi e inc ease in compa ison o he eco ds made a 30 DAS, i espec i e o
S iga seed bank size (Table 4).A 90 DAS, lea a ea showed mo e o less he same end, a p og essi e decline
wi h S iga seed bank size. In e c opping wi h cowpea B301 and T100K-901-6, i espec i e o S iga in es a ion
inc eased so ghum lea a ea in compa ison o sole so ghum (Table 4). A consis en p og essi e decline in lea
a ea was in a iably a ec ed wi h inc easing S iga seed bank size. Howe e , he o e all e ec ac oss S iga
seed bank le els was a p og essi e decline wi h inc easing seed bank size wi h signi ican educ ions a ained a
he highes S iga in es a ion le els (16 and 32 mg/po ). So ghum in e c opped wi h cowpea T100K-901-6,
i espec i e o ime, showed a consis en decline in lea a ea wi h S iga seed bank size (Table 4).
D y weigh :
So ghum d y weigh i espec i e o in e c opping dec eased wi h inc easing S iga seed bank size (Table
5). S iga seed bank size a 1and 2 mg/ po educed so ghum d y weigh by 7.7 and 22.5%, espec i ely.
Inc easing S iga seed bank size o 4, 8, 16 and 32 mg/ po educed so ghum d y weigh by 31.9, 39.3, 54.8 and
60.7 %, espec i ely in compa ison o he espec i e S iga ee con ol.
In e c opped so ghum in a iably showed signi ican ly highe d y weigh han he sole c op (Table 5).
Howe e , i showed mo e o less he same ends in educ ion wi h S iga seed bank as sole so ghum in
compa ison o he espec i e S iga ee con ol (Table 5). S iga ee so ghum in e c opped wi h cowpea B301
and T100K-901-6 displayed a d y weigh o 134.8 and 150g, espec i ely (Table 5). S iga a he lowes seed
bank educed so ghum d y weigh by 2 and 4 %, he obse ed educ ion was no signi ican . Inc easing S iga
seed bank o 8, 16 and 32 mg/ po dec eased so ghum d y weigh by 60.7- 70.3 %, and 57.7-67.3%, espec i ely
and he obse ed educ ions we e signi ican .
Second expe imen , e ec s o in e c opping, bac e ial s ains and ino ganic phospho us on S iga incidence and
so ghum g ow h:
E ec s on S iga:
Resul e ealed ha mos o ea men s dec eased S iga eme gence conside ably in compa ison o he
con ol (Table 6). Fu he mo e, S iga eme gence p og essi ely inc eased wi h ime. A 30 DAS, S iga
eme gence was e y low as only 0.33 S iga plan s eme ged on he un ea ed con ol. Howe e , no any S iga
eme gence was obse ed on so ghum in e c opped wi h cowpea T100K-901-6 geno ype alone o in combina ion
wi h Rhizobium, BMP and phospho us a he highes dose. A 60 DAS, S iga eme gence inc eased,
subs an ially, and was highes on he un e ilized un-inocula ed con ol (7 S iga plan s/ po ). In e c opping wi h
cowpea inocula ed wi h each o Rhizobium alone o o BMP each alone o in combina ion wi h phospho us a 92
kg ha-1 educed S iga eme gence in he ange o 93-100%, espec i ely. A 75 DAS, S iga eme gence on sole
so ghum showed simila end as in 60 DAS. Cowpea in e c opping ea ed wi h Rhizobium plus phospho us a
he highes dose comple ely inhibi ed S iga eme gence. A 90 DAS, in e c opping wi h cowpea, p e iously
inocula ed wi h Rhizobium alone o in combina ion wi h phospho us a 92 kg ha-1 educed S iga eme gence by
92 and 96%, espec i ely as compa ed wi h he co esponding con ol. The S iga eme gence da e was delayed
by 75 days in cowpea p e iously ea ed wi h Rhizobium plus phospho us a 92 kg ha-1, compa ed o he con ol.
E ec s on so ghum heigh (cm.):
So ghum heigh , i espec i e o ea men , displayed p og essi e inc ease wi h ime and dec eased wi h
S iga in es a ion (Table. 7).In gene al, he majo i y o he ea men s esul ed in heigh s compa able o he
co esponding con ol (S iga in es ed sole so ghum). Sole so ghum displayed be e g ow h han so ghum
in e c opped wi h cowpea, in p esence o absence o S iga. A 30 DAS, cowpea inocula ed wi h Rhizobium
alone o in combina ion wi h phospho us, BMP plus phospho us esul ed in a signi ican inc ease in plan heigh
compa able o he co esponding con ol. Among o he ea men s, so ghum in e c opped wi h cowpea,
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Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
p e iously inocula ed wi h he combina ion o BMP plus Rhizobium plus phospho us a 46 kg ha-1 o 92 kg ha-1,
displayed he highes g ow h. A 60 DAS, so ghum in e c opped wi h cowpea inocula ed wi h he combina ions
o Rhizobium plus BMP plus phospho us a 92 kg ha-1,Rhizobium plus BMP plus phospho us a 46 kg ha-1,
sus ained he highes g ow h as compa ed o he co esponding con ol. A 90 DAS, S iga educed so ghum
heigh signi ican ly as compa ed wi h he co esponding con ol. Among all ea men s, Rhizobium alone o in
combina ion wi h phospho us plus BMP we e he mos s imula o y e ec on so ghum g ow h. So ghum heigh
was nega i ely co ela ed wi h S iga eme gence.
Chlo ophyll con en :
A 30 DAS, he e we e signi ican di e ences be ween he ea men means wi h ega d o so ghum
chlo ophyll con en (Table 8). Among ea men s, so ghum in e c opped wi h cowpea T100K-901-6, p e iously
inocula ed wi h BMP plus phospho us a he highes dose displayed he highes chlo ophyll con en . A 60 and
90 DAS, SPAD alue declined wi h ime as well as S iga in es a ion.
Lea a ea:
Lea a ea, i espec i e o in e c opping o ime, dec eased wi h S iga in es a ion (Table 9).So ghum ee
S iga plan in he con ol po had he highes lea a ea. A 30 DAS, sole so ghum, in a iable, showed a
p og essi e decline in lea a ea wi h S iga albei no signi ican ly, in compa ison o he S iga ee con ol.
In e c opping wi h cowpea inocula ed wi h Rhizobium plus phospho us a 92 kg ha-1inc eased so ghum lea a ea
by 70% in compa ison o sole so ghum. A 60 DAS, lea a ea o sole so ghum showed a p og essi e inc ease in
compa ison o he eco ds made a 30 DAS. In e c opping wi h cowpea inocula ed wi h he combina ion o
Rhizobium and BMP plus phospho us a 92 kg ha-1 inc eased so ghum lea a ea by 9%, in compa ison o sole
so ghum. A 90 DAS, lea a ea showed mo e o less he same end, a p og essi e decline wi h S iga
in es a ion. Howe e , signi ican inc emen s we e only a ained a so ghum in e c opped wi h cowpea
inocula ed wi h Rhizobium alone o in combina ion wi h BMP plus phospho us a 92 kg ha-1by 56 and 50%,
espec i ely.
D y weigh :
The e we e signi ican di e ences among he ea men means wi h ega ds o o al so ghum biomass
(Tables 10). So ghum d y weigh i espec i e o in e c opping dec eased wi h S iga in es a ion (Tables 10).
S iga ee so ghum and in es ed c op showed oo d y weigh o 68 and 36/po , espec i ely (Table 10).
In e c opped so ghum in a iable showed highe d y weigh han he sole c op. All ea men inc eased oo d y
weigh signi ican ly as compa ed o he con ol. Cowpea inocula ed wi h Rhizobium inc ease so ghum oo d y
weigh signi ican ly as compa ed o sole so ghum con ol. Almos all ea men s inc eased shoo d y weigh as
compa ed o he con ol. Among o he ea men s so ghum in e c opped wi h cowpea inocula ed wi h BMP
alone o in combina ion wi h Rhizobium plus phospho us a 46 kg ha-1 sus ained he highes shoo d y weigh .
Discussion:
Soil e ili y deple ion is he majo limi ing ac o in c op p oduc ion in A id and semi-a id lands [8].
Con inuous mono-c opping o ce eal c ops wi hou allowing has wo sened he si ua ion. S iga he mon hica, a
pa asi ic weed, has long been belie ed o be co ela ed wi h he declining soil e ili y s a us. Legumes hold
g ea po en ial as sou ces o high p o ein ood and eed [9]. They also enhance N up ake and plan capaci y o
wi hs and d ough [10]. No mally, o op imal legume-Rhizobium symbiosis o occu , a su icien amoun o
phospho us is equi ed, while ce eals need conside ably la ge amoun s o bo h N and P o op imal g ow h [11].
I is no ewo hy ha a plan species may p oduce se e al s igolac ones which di e signi ican ly in hei
ge mina ion inducing ac i i y (GIA) and ha he main s igolac one om so ghum and cowpea we e epo ed o
be so golac one and alec ol, espec i ely [12]. Cowpea is no pa asi ized by S. he mon hica, howe e , i is a
hos o he closely ela ed species S.gesne iodies. In he p esen wo k a holis ic app oach was adop ed wi h he
objec i es o p o iding in o ma ion on in e c opping in g eenhouse expe imen s whe e in e c opping was
in eg a ed wi h inocula ion o R. leguminosa um and B. mega he ium a phospha icum, a phospho us
solubilizing bac e ium and ino ganic phospho us. In he i s g eenhouse expe imen , i espec i e o
in e c opping, S iga eme gence p og essi ely inc eased wi h seed bank size (Table 1). Howe e , in e c opping
wi h cowpea, i espec i e o ime and seed bank size delayed and ep essed S iga eme gence, signi ican ly in
compa ison o sole so ghum whe e he educ ions a ied be ween 50 and 100% and 1and 30 % a he lowes and
highes seed bank size, espec i ely. The educ ion in he pa asi e eme gence could be as poin ed ou by Pa ke
and Riches [ 5], in simila si ua ions, due o induc ion o ge mina ion by he ad ancing cowpea oo s away om
hose o so ghum and/o compe i ion be ween cowpea oo s and hose o so ghum o he ju enile S iga
ge milings. Ni ogen ixed by he legumes has also been poin ed as a eason o S iga con ol. Incidence o
S iga is known o nega i ely co ela e wi h soil e ili y, pa icula ly ni ogen a ailabili y [13]. S iga d y
weigh , in a iably, inc eased a a as e a e on sole so ghum han in e c opped plan s (Table 5). A he lowe

6 Es a A Mahmoud e al, 2016
Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
seed bank size, S iga d y weigh om unde so ghum in e c opped wi h cowpea T100K-906-1 educed by
22.8%. A S iga seed bank size o 4 - 32 mg/po in e c opping wi h cowpea B301 and T100K-906-1 educed
S iga d y weigh by 39.5- 49.2.% and 59.5 – 61.7%, espec i ely. The educ ion in S iga d y weigh is
consis en wi h he educ ions in eme gence ins iga ed by in e c opping wi h cowpea. The high anspi a ion a e
enhances ans e o hos xylem sap in o he pa asi e. In e c opping shades he soil and lowe s he empe a u e.
Fu he mo e educed anspi a ion and pho osyn hesis o he pa asi e esul ing om shading by he in e c op, as
epo ed in simila si ua ions [4, 5], could accoun , a leas in pa , o a conside able p opo ion o he loss in
d y weigh . So ghum heigh , i espec i e o in e c opping, displayed a p og essi e dec ease wi h S iga seed
bank size (Table 3). Howe e , he in e c opped so ghum wi h cowpea geno ypes appea ed o display be e
g ow h han sole so ghum. Lea a ea, i espec i e o in e c opping, dec eased wi h S iga seed bank size (Table.
4). Lea a ea was in a iably highe o in e c opped so ghum. As indica ed by he magni ude o he educ ion in
lea a ea wi h ime i would appea ha limi ed eco e y in lea a ea occu ed wi h ime. So ghum in e c opped
wi h cowpea geno ype T100K-901-6 displayed less educ ion in lea a ea han he one in e c opped wi h cowpea
B301 and sole so ghum c op. So ghum d y weigh , i espec i e o in e c opping, p og essi ely declined wi h
S iga seed bank. Howe e , d y weigh o in e c opped so ghum, i espec i e o S iga seed bank size, was
in a iably highe han ha o sole so ghum. The d y weigh o in e c opped S iga ee so ghum was abou 2-
old ha o he espec i e S iga ee sole so ghum. Such a di e ence could be a ibu ed, a leas in pa , o
di e ences in he geno ypes used. In he p esen s udy cowpea geno ypes wi h p os a e and sp eading habi
we e employed. Fu he mo e, cowpea is a legume and a ni ogen ixe . T ans e o ni ogen and possibly
phospho us om legumes o neighbo ing non-leguminous plan s om decaying cowpea oo s and nodules has
been epo ed by [12, 14]. Gbehounou and Adango [14] poin ed ou ha in e c opping wi h cowpea leads o
highe yield, and ha his may be ela ed o he bene i s o ni ogen ixa ion unde cowpea c opping, as well as a
educ ion in leaching o soil nu ien s by cowpea co e .
In he second expe imen , ea men s comp ising so ghum in e c opped wi h cowpea T100k-901-6,
inocula ed wi h B. mega he ium, R. leguminosa um, phospho us o hei combina ions sus ained and main ained
signi ican ly less S iga eme gence han sole so ghum (Table6). A ea ly season, educ ions in S iga eme gence
on so ghum in e c opped wi h cowpea T100k-901-6 inocula ed wi h B. mega he ium, R. leguminosa um and
hei combina ion we e 43,89 and 69%, espec i ely, in compa ison o ha on sole so ghum. Howe e , he
educ ion was inc eased in p esence o phospho us alone o in combina ion o bac e ial s ains (54 -100%). I is
no ewo hy, albei di e ences be ween he indi idual ea men s we e o en no signi ican , ha inocula ing
cowpea wi h he bac e ial combina ions and phospho us we e he mos e ec i e in supp essing he pa asi e
eme gence. Howe e , in e c opping wi h cowpea, inocula ed wi h R. leguminosa um alone o in combina ion
wi h phospho us, i espec i e o ime, delayed and ep essed S iga eme gence, signi ican ly in compa ison o
sole so ghum whe e he educ ion a ied be ween 98 and 92%, espec i ely. The educ ion in he pa asi e
eme gence could be as poin ed ou by Pa ke and Riches [5], in simila si ua ion, due o induc ion o
ge mina ion by he ad ancing cowpea away om hose o so ghum and/o compe i ion be ween cowpea oo s
and hose o so ghum o he ju enile S iga ge milings. Fu he educed anspi a ion and pho osyn hesis o he
pa asi e esul ing om he shading by he in e c opped plan s [5]. These indings ag ee wi h Musyoka [ 15].
S iga eme gence was delayed in cowpea ea ed wi h Rhizobium plus phospho us a 92 kg ha-1. In e c opping
cowpea geno ypes may cause suicidal ge mina ion o some o S iga seeds whe eas he bac e ial inoculum
would inhibi S iga ge mina ion and/o eme gence [ 16]. Supp ession o S iga eme gence, d y weigh and he
inc ease in so ghum d y weigh and he associa ion o he maximum inc emen s wi h he combina ion o R.
leguminosa um plus B. mega he ium and phospho us a e consis en wi h epo s by Musyoka[ 15] who obse ed
o e 2-3- old inc ease in so ghum and g asses g ow h a ibu es on in e c opping o so ghum wi h cowpea
inocula ed wi h a comme cial Rhizobium s ain oge he wi h u he supplemen a ion o ino ganic phospho us.
They a ibu ed he imp o emen o cowpea in e c opped so ghum and g asses in legume/g ass pas u es o
inc eased a ailabili y o ni ogen h ough biological ni ogen ixa ion. Fu he mo e, S iga in es a ion and
damaging e ec s a e also linked wi h low soil e ili y and ha ni ogen and phospho us play key oles in he
pa asi ic synd ome [4]. The use o legumes oge he wi h inocula ion wi h Rhizobium as e ealed by
Musyoka[15] and phospho us solubilizing bac e ia as shown in his s udy may p o ide he cheapes iable
op ion o he esou ce- cons ain sub-Saha an A ican a me s o imp o e soil e ili y and consequen ly imp o e
c op pe o mance and S iga managemen . These esul s demons a ed ha S iga bio-con ol based on bac e ial
inoculum inco po a ion and he in e c opping sys em cons i u e each an e ec i e con ol me hod agains S.
he mon hica and hei syne gis ic e ec is mo e e ec i e o educe he pa asi e in es a ion. Soil mic oo ganisms
and in e c opping in e e ing wi h ea ly de elopmen al s ages we e hough o as possible al e na i es and/o
iable supplemen s o o he con ol me hods [17].
7 Es a A Mahmoud e al, 2016
Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
Conclusions:
The echnical and economic easibili y o in eg a ing in e c opping wi h cowpea geno ypes B301 and
T100K-901-6, inocula ed wi h R. leguminosa um TAL1399and he phospho us solubilizing bac e ium B.
mega he ium a phospha icum wi h exis ing measu es o S iga managemen should be conside ed and
e alua ed unde a me ’s ield condi ions adop ing an e icien pa icipa o y app oach. Fu he s udies a e
needed o unde s and he impac o a me managemen p ac ices on S iga in es a ion and soil e ili y.
Table 1: E ec s o so ghum in e c opping wi h cowpea and seed le el o S iga on S iga incidence (S iga eme gence)
S iga seed le el (mg/po )
S iga eme gence (plan /po )
Time a e c op sowing (Days)
30
60
90
Mean
a-Sole so ghum
1
3.0 (±1.1) c
7.0 (±1.6) d
13.3 (±1.9) d
7.8 d
2
6.5 (±0.6) bc
12.0 (±1.5) c
17.5 (±1.0) cd
12.0 c
4
7.5 (±0.6) b
13.5 (±0.6) bc
21.3 (±0.9) abc
14.1 bc
8
9.5 (±0.6) b
15.0 (±0.4) bc
20.0 (±1.1) bc
14.8 b
16
10.0 (±2.7) b
16.3 (±1.3) ab
23.0 (±1.6) ab
16.4 b
32
14.3 (±0.9) a
18.5 (±0.6) a
25.0 (±1.8) a
19.3 a
Mean
8.5 c
13.7 b
20.0 a
b-cowpea B301
Mean
1
0.3 (±0.3) d
0.5 (±0.3) d
0.5 (±0.3) d
0.4 e
2
0.8 (±0.5) cd
1.5 (±0.6) d
1.8 (±0.6) cd
1.3de
4
1.5 (±1.0) cd
2.3 (±0.9) cd
2.5 (±0.9) cd
2.1 d
8
3.3 (±0.5) c
4.5 (±1.6) c
5.5 (±1.3) c
4.4 c
16
6.8 (±0.9) b
8.8 (±0.9) b
11.8 (±1.5) b
9.1 b
32
13.0 (±1.5) a
16.8 (±1.0) a
24.8 (±2.5) a
18.2 a
Mean
3.6 a
4.9 a
6.7 a
ccowpeaT100K901-6
1
0.0 (±0.0) c
0.5 (±0.5) c
0.5 (±0.5) c
0.3 d
2
0.8 (±0.5) bc
1.3 (±0.8) c
1.0 (±0.4) c
1.0 d
4
1.8 (±0.8) bc
2.3 (±1.1) c
2.5 (±1.3) c
2.2 cd
8
3.3 (±1.8) bc
4.0 (±1.5) c
4.5 (±1.7) c
3.9 c
16
5.3 (±1.3) b
9.0 (±0.8) b
9.5 (±1.6) b
7.9 b
32
10.0 (±3.1) a
17.0 (±2.2) a
19.0 (±2.4) a
15.3 a
Mean
3.0 a
4.9 a
5.3 a
Table 2: E ec s o so ghum in e c opping wi h cowpea and seed le el o S iga on S iga d y weigh
S iga seed le el
(mg/po )
S iga d y weigh (g)
Sole So ghum
B301
T100K-901-6
Mean
1
24.3 (±2.4) d
30.5 (±2.3) c
19.0 (±2.3) c
24.6 d
2
42.5 (±6.2) cd
32.0 (±0.9) c
21.8 (±1.5) bc
32.1 cd
4
56.8 (±7.4) bc
34.5 (±5.0) bc
23.0 (±3.1) bc
38.1 bc
8
76.8 (±15.9) ab
40.8 (±4.2) abc
29.0 (±3.5) ab
48.8 ab
16
86.8 (±2.5) a
44.0 (±5.3) ab
33.3 (±4.7) a
54.7 a
32
91.3 (±2.4) a
46.3 (±3.1) a
35.0 (± ) a
57.5 a
Mean
63.0 a
38.0 b
26.8 c
42.6
Table 3: E ec s o so ghum in e c opping wi h cowpea and seed le el o S iga on so ghum g ow h (so ghum heigh )
So ghum heigh (cm)
Time a e sowing (Days)
S iga seed le el (mg/po )
30
60
90
Mean
a- Sole so ghum
0
15.8 (±1.8) a
19.0 (±2.0) a
24.5 (±2.6) ab
19. a
1
15.0 (±2.2) ab
18.8 (±1.9) a
26.3 (±1.8) a
20 a
2
14.0 (±0.9) ab
18.8 (±1.5) a
24.0 (±1.6) abc
18.9 ab
4
15.5 (±1.0)a
18.3 (±1.3) a
20.3 (±1.3) bcd
18 ab
8
12.5 (±1.0) abc
16.5 (±0.6) ab
19.8 (±0.9) cde
16. abc
16
11.5 (±0.6) bc
15.8 (±0.5) ab
18.5 (±0.6) de
15. bc
32
9.5 (±1.0) c
13.3 (±0.9) b
15.5 (±0.6) e
12. c
Mean
13.4 c
17.2 b
21.3 a
8 Es a A Mahmoud e al, 2016
Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
b-cowpeaB301
0
24.8 (±2.9) a
27.8 (±3.4) a
31.3( ±2.4) a
27.9 a
1
22.8 (±3.1) ab
24.3 (±3.0) ab
30.5 (±1.7) a
25.8 ab
2
18.8 (±1.1) abc
22.3 (±2.1) abc
26.5 (±2.5) ab
22.5 bc
4
20.5 (±1.3) bc
21.8 (±1.4) bc
24.5 (±1.8) bc
22.25 bc
8
18.3 (±0.9) bc
19.3 (±0.5) bc
22.3 (±1.1) bc
19.9 c
16
17.5 (±0.6) bc
19.0 (±0.7) bc
21.5 (±1.3) bc
19.3 c
32
15.3 (±0.9) c
17.5 (±0.6) c
20.0 (±0.7) c
17.6 c
Mean
19.8 b
21.7 b
25.2 a
c- T100K-901-6
0
26.0 (±1.5) a
30.3 (±1.3) a
34.5 (±1.7) a
30.3 a
1
24.3 (±3.1) ab
29.3 (±1.5) ab
30.5 (±1.6) ab
28.0 ab
2
21.0 (±1.5) bc
28.3 (±1.2) ab
29.0 (±0.7) ab
26.1 abc
4
20.0 (±1.1) bc
27.0 (±3.0) abc
27.5 (±3.3) b
24.8 bc
8
19.3 (±0.8) c
23.8(±2.7) bcd
25.0 (±2.6)bc
22.7 cd
16
18.0 (±1.1) c
21.5 (±2.6) cd
24.3 (±2.1) bc
21.3 cd
32
16.5 (±0.6) c
19.0(±1.7) d
19.0 (±2.4) c
18.2 d
Mean
20.7 a
25.6 a
27.1 a
Table 4: E ec s o so ghum in e c opping wi h cowpea and seed le el o S iga on so ghum lea a ea
Lea a ea(cm2)
S iga seed le el (mg/po )Day A e Sowing (DAS)
30 60 90 means
a-Sole so ghum
0
45.0 (±6.1) a
53.3 (±5.3) a
73.6 (±6.7) a
57.3 a
1
38.1 (±5.9) ab
54.0 (±9.3) a
69.9 (±6.4) ab
54.0 ab
2
32.9 (±7.6) abc
46.0 (±11.0) ab
60.7(±10.8)ab
46.5 ab
4
28.1(±7.5) bcd
43.2 (±9.6) ab
58.1(±9.4) bc
43.1 abc
8
23.5 (±5.3) bcd
39.2 (±8.4) ab
55.8(±7.9) bc
39.5 abc
16
20.3 (±4.2) cd
37.4 (±6.7) ab
50.7 (±4.8) bc
36.1 bc
32
15.1 (±2.4) d
23.1 (±2.8) b
36.1 (±4.0) c
24.8 c
Mean
29.0 c
42.3 b
57.8 a
b-B301
0
141.8 (±30.3) a
170.4 (±27.1) a
176.8(±19.0)a
163.0 a
1
130.1 (±15.0) a
160.0 (±8.7) ab
173.5(±31.3)a
154.5 ab7
2
123.4 (±14.6) a
143.8(±12.5) bc
166.1(±16.7)a
144.4 abc
4
117.5 (±15.3) a
139.6(±7.3) abc
149.4(±25.1)a
135.5 abc
8
114.6 (±13.9) a
130.4(±10.4)abc
134.1(±21.0)a
126.4 abc
16
104.1 (±15.1) a
126.6(±12.4) bc
118.4(±17.8)a
116.3 bc
32
95.6 (±13.4) a
106.8 (±12.7) c
116.4(±18.6)a
106.0 c
Mean
118.1b
139.6 a
147.8 a
c-T100K-901-6
0
157.4 (±19.8) a
171.8 (±11.5) a
182.9 (±13.2) a
170.7 a
1
154.3 (±17.4) a
157.6 (±9.2) a
163.5 (±17.5) a
158.5 ab
2
142.0 (±14.0) a
150.7 (±9.9) a
155.6 (±16.8) a
149.4 ab
4
138.2 (±29.4) a
148.1 (±20.2) a
155.2 (±26.3) a
147.1 ab
8
124.2 (±18.4) a
144.6 (±16.1) a
144.9 (±21.9) a
137.9 ab
16
118.7 (±21.7) a
131.7 (±7.2) a
142.1 (±11.7) a
130.8b
32
104.2 (±23.4) a
128.3 (±31.1) a
138.3 (±24.0) a
123.6 b
Mean
134.1b
147.5 ab
154.6 a
Table 5: E ec s o so ghum in e c opping wi h cowpea and seed le el o S iga on so ghum d y weigh
S iga seed
le el(mg/po )
So ghum d y weigh (g)
Sole so ghum
B301
T100K-901-6
Mean
0
67.5 (±11.2) a
134.8 (±19.4) a
150.0 (±16.6) a
117.4 a
1
62.3 (±7.6) ab
131.8 (12.7) a
144.0 (±13.5) ab
112.7 a
2
52.3 (±4.9) abc
104.8 (±11.6) ab
116.3 (±12.2) bc
91.1 b
4
46.0 (±8.9) bcd
73.0 (±18.1) bc
84.3 (±13.0) cd
67.8 c
8
40.3 (±4.8) cd
53.0 (±8.3) c
63.5 (±8.8) de
52.3 cd
16
30.5 (±1.4) d
52.5 (±4.3) c
58.0 (±3.4) de
47.0 cd
32
26.5 (±3.5) d
40.0 (8.4) c
49.0 (±4.3) e
38.5 d
9 Es a A Mahmoud e al, 2016
Ad ances in En i onmen al Biology, 10(7) July 2016, Pages: 1-11
Mean
46.5 b
84.3 a
95.0 a
Table 6: E ec s o so ghum in e c opping wi h cowpea, bac e ial s ains and ino ganic e ilize , on S iga eme gence Days a e sowing
(DAS)
S iga eme gence
day a e sowing (DAS)
T ea men s
30
60
90
I.C s(+)
0.0000 A
2.3333 A
6.3333 AB
so ghum s(+)
0.3333 A
7.10 A
16.000 A
I.C +P1
0.6667 A
2.0000 A
2.3333 B
I.C +P2
0.0000 A
2.6667 A
4.6667 AB
I.C+ izo
0.0000 A
0.6667 A
2.0000 B
I.C + izo+P1
0.3333 A
3.6667 A
4.6667 AB
I.C + izo+P2
0.0000 A
0.0000 A
1.0000 B
I.C + BMP
0.6667 A
7.3333 A
10.000 AB
I.C + BMP+P1
0.6667 A
5.3333 A
4.0000 B
I.C + BMP+P2
0.0000 A
7.0000 A
8.6667 AB
I.C +BMP+Rizo
0.0000 A
3.6667 A
4.0000 B
I.C +BMP+Rizo+P1
0.6667 A
3.6667 A
3.0000 B
I.C +BMP+Rizo+P2
0.0000 A
1.3333 A
6.0000 AB
S anda d e o (±)
0.57
4. 42
5.56
I.C.: So ghum in e c opped wi h cowpea;P1 and P2: Phospho us a 46 kg ha-1 and 92 kg ha-1, espec i ely. izo: Rhizobium
leguminosa um:BMP: B.mega he ium; +: in p esence o S iga; -: in absence o S iga
Table 7: E ec s o so ghum in e c opping wi h cowpea, bac e ial s ains and ino ganic e ilize on so ghum heigh
So ghum heigh (cm)
day a e sowing (DAS)
T ea men s
30
60
90
I.C s(-)
78.50 A
80.83 AB
76.00 ABCD
so ghum s(-)
73.28 AB
86.36 A
92.94 A
I.C s(+)
54.17 BC
62.08 E
71.17 ABCD
so ghum s(+)
54.67 BC
73.5 ABCDE
69.78 ABCD
I.C +P1
63.00 ABC
64.33 DE
52.50 BCD
I.C +P2
54.75 BC
73.8 ABCDE
67.17 ABCD
I.C+ izo
70.33 ABC
70.1 BCDE
78.00 ABC
I.C + izo+P1
75.00 AB
69.75 BCDE
49.83 CD
I.C + izo+P2
75.67 AB
78.00 ABC
75.17 ABCD
I.C + BMP
62.67 ABC
66.75 CDE
60.79 BCD
I.C + BMP+P1
50.50 C
60.88 E
57.02 BCD
I.C + BMP+P2
71.33 ABC
70.91 BCDE
49.17 D
I.C +BMP+Rizo
67.83 ABC
68.58 BCDE
64.33 ABCD
I.C +BMP+Rizo+P1
76.83 A
76.25 ABCD
77.00 ABCD
I.C +BMP+Rizo+P2
76.83 A
80.50 AB
80.67 AB
S anda d e o (±)
10.51
6.44
14.07
I.C.: So ghum in e c opped wi h cowpea;P1 and P2: Phospho us a 46 kg ha-1 and 92 kg ha-1, espec i ely. izo: Rhizobium
leguminosa um:BMP: B.mega he ium; +: in p esence o S iga; -: in absence o S iga
Table 8: E ec s o so ghum in e c opping wi h cowpea, bac e ial s ains and ino ganic e ilize , on chlo ophyll con en on so ghum
Chlo ophyll con en
Day A e Sowing (DAS)
T ea men s
30
60
90
I.C s(-)
36.600 AB
27.667 BC
21.36 ABC
so ghum s(-)
39.167 A
37.933 A
29.367 A
I.C s(+)
30.500 C
24.20 BCD
14.76 BCD
so ghum s(+)
35.633 AB
30.067 AB
23.700 AB