Management of root knot nematode, Meloidogyne incognita(Kofoid and white) chitwood in vegetable cowpea
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Date
2020
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Department of Nematology, College of Agriculture, Vellayani
Abstract
The study entitled 'Management of root-knot nematode, "'Meloidogyne
incognita (Kofoid and White) Chitwood in vegetable cowpea" was conducted at
Department of Nematology, College of Agriculture, Vellayani, Thiruvananthapuram
during 2018-2020. The objectives were to screen varieties for resistance and to
evaluate efficacy of biocontrol agents, organic amendment and new nematicide
fluopyram for the management of root-knot nematode in vegetable cowpea.
Seven varieties of vegetable cowpea (5 KAU released and 2 local) were
screened for their resistance against Meloidogyne ineognita in pot culture under glass
house condition. Tie experiment was laid out in CRD with 7 treatments and 3
replications. The results levealed that local variety collected flxrm Kadakkal was
highly resistant to root-knot nematode with root-knot index 1. The local variety
performed best in reducing the multiplication of nematodes. Lowest number of egg
masses 5g roof'( 2.33), eggs egg mass' ( 63.33) and nematode population 200cc soil'
(7 33) was observed in the local variety and it showed statistically significant
variation compared to the KAU released varieties. Regarding the number of nodules
5g roof' also the Kadakkal variety showed significant superiority (22.67 nodules 5g
roof') KAU variety VS 50 was highly susceptible to M. incogniia mfestatron w.th
root-knot index 5. Highest number of egg masses 5g roof'(224.33) and number eggs
egg mass"' (147.00) was recorded in VS 50.
pot culture experiment was laid out in completely randomized design to
stanHda rHdi zzle tthhe dosJage of fluopyram for the m^an ageme^nt. o f K ^incogniu. m cowpea.
THe treatme^s w ^ ^
fluopyram 400 @ ^ ^ ,^S Og a., ha
first treatment, flu ^ 250g a.i ha' as basal application,
25 days after first ^ J^s soil drenching to the root untreated. All .e --7-:^;:::::L,yram 400 SC @ 250g a.i ha ' knot nematode infected so . ^ ^ ^
was the effective dosage or . ^ y of the treatments. Nematode
Phytotoxicity symptoms were not observed any
penetration in roots and life eyele completion was obser\'ed in untreated control
plants. M. inco^niui juveniles, adult female and male were not observed in roots of
fluopyram treated cowpea plants. Galls and egg masses were observed in uprooted
cowpea plant roots in untreated whereas in fluopyram applied treatments it was zero.
Regarding final nematode population also, no nematodes were observed in soil
samples were collected from fluopyram treated plants while in untreated control
plants it was 761.5. Number of rhizobium nodules was significantly lower in
untreated plants (17.75) while in fluopyram treated plants it ranged from 24.25 to 27.5
in 5g roots of cowpea plants.
Field experiment was conducted by using the susceptible variety (VS 50) to
stiidy the comparative effect of bio agents (Purpiireocillium lilacinum) and organic
amendment (neem cake) in comparison with chemicals fluopyram and carbosulfan.
The experiment was laid out in RED with 8 treatments and 3 replications. All the
treatments significantly reduced nematode population in soil and root compared to
untreated control. Effect of soil application of P. lilacinum (cfu 2x10*' g"') @ 10 g
^ cake @ 50 g m'^ found equally effective to basal application fluopyram
400 SC @ 250g a.i ha"' in reducing the nematode population in soil (93.03 per cent
reduction over untreated) and root (86.94 per cent reduction over untreated).
Regarding yield also effect of these two treatments was statistically on par giving
53 70 to 54.63 per cent increase over untreated. Plants treated with P. lilacinum (cfti
2x10^ g"') @ 10 g + neem cake @ 50 g m"^ showed significant superiority in
number of nodules (29.33) in root (5g). Results on reisolation of bioagents at the time
of harvest revealed that addition of organic substrate neemcake increased the
persistence of bioagent (8.33x10^ cfn g soif') in soil. Residue of fluopyram and
carbosulfan was found to be less than limit of quantification (LOQ) m cowpea pods,
which were safe for consumption.
From this study, it is concluded that vegetable cowpea variety Kadakkal local
is resistant to M. incognita. Soil application off. lilacinum (cfu 2x106 g-1) @ 10 g
+ neem cake @ 50 g m'^ can be recommended for management of M. incognita
in organic cultivation of cowpea.
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MSc
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Citation
174906