Journal of Applied Microbiology (2021) 130, 424-438

M.R. Khan, Z. Haque, F. Ahamad and B. Zaidi (2021)
Biomanagement of rice root-knot nematode Meloidogyne graminicola using five indigenous microbial isolates under pot and field trials
Journal of Applied Microbiology 130 (2), 424-438
Abstract:
Aims
To ascertain the effectiveness of Aspergillus niger, Trichoderma harzianum, Pochonia chlamydosporia, Bacillus subtilis and Pseudomonas fluorescens against rice root-knot nematode, Meloidogyne graminicola, and to optimize their application methods.
Methods and Results
The relative effectiveness of five indigenous biocontrol agents (BCA) against M. graminicola on rice cv. PS-5 was tested initially in pot culture. The BCAs, A. niger, P. chlamydosporia and P. fluorescens proved more effective, and significantly reduced the nematode disease. It is hypothesized that success of a biocontrol module may vary with the BCA and application methods. Hence, the effectiveness of the above three BCAs as well as seven different treatment schemes were evaluated in naturally infested farmer's fields during 2 consecutive years. In nematode-infested plots without any BCA treatments, terminal galls formed on the roots, and plants suffered a 19–31% decrease in the growth and yield. The treatments with P. chlamydosporia or A. niger through root-dip (RD) plus one soil application (SA) at 15 days after planting were found to be highly effective against the nematode.
Conclusions
Relatively greater nematode control was achieved with RD plus two SAs (15 + 30 DAP) but statistically the effect was on par with RD + one SA at 15 DAP. These treatments significantly reduced galling (22–25%), egg mass production (21–29%) and reproduction factor (63–70%) of M. graminicola, and subsequently increased the grain yield (11–21%).
Significance and Impact of the Study
Application methods enhanced the effectiveness of BCAs against M. graminicola. The RD plus one SA at 15 DAP proved to be most effective treatment to control root-knot disease in rice. Use of multiple treatments (root dip and SA) appears cumbersome, but in view of effectiveness and limitation of chemical control in rice paddies, farmers may adopt the above module that may lead to 11–21% yield improvement.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mujeebur Rahman Khan

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne graminicola	Rice (Oryza)
Pochonia chlamydosporia (antagonist)	Meloidogyne graminicola
Pseudomonas fluorescens (antagonist)	Meloidogyne graminicola
Aspergillus niger (antagonist)	Meloidogyne graminicola