Slide1 l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

Are Nematodes a Problem in SRI? PowerPoint PPT Presentation


  • 128 Views
  • Uploaded on
  • Presentation posted in: General

Are Nematodes a Problem in SRI? . J.S. Prasad, Ch. Padmavathi, R.M. Kumar, and L.V.Subba Rao. Directorate of Rice Research, Rajendranagar, Hyderabad-500 030. INTRODUCTION.

Download Presentation

Are Nematodes a Problem in SRI?

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Slide1 l.jpg

Are Nematodes a Problem in SRI?

J.S. Prasad, Ch. Padmavathi,

R.M. Kumar, and L.V.Subba Rao

Directorate of Rice Research,

Rajendranagar, Hyderabad-500 030


Slide2 l.jpg

INTRODUCTION

  • High yields of rice declined in Brazil and China after 3-4 years under aerobic conditions, possibly due to nematodes or toxic substances (Bouman, 2002).

  • Yield differences between aerobic and flooded rice ranged from 8 to 69%, the differences attributed to the build-up of nematodes (Peng et al., 2006).

  • Under controlled irrigation, even small pest problems have great impacts on yields and farmers' income.


Slide3 l.jpg

Nematode pests that could be associated with SRI

Uncontrolled irrigation can be associated with the rice root nematode

Hirschmanniella spp. – yield loss 8-23% (Kuriyan and Sheela, 1981)


Slide4 l.jpg

Controlled irrigation can be associated with the root-knot nematode Meloidogyne graminicola -- yield loss 21-64 % (Rao and Biswas, 1973)


Slide5 l.jpg

Giant cell formation induced by the root-knot nematode in phloem


Slide6 l.jpg

Materials and methods

Field Experiment – Split Plot

Treatments: SRI, Eco-SRI, and Conventional

Varieties: Rasi and Jaya

  • Greenhouse studies

  • Treatments:

  • Continuous flooding

  • Optimum moisture (OM)

  • Flooding & OM alternated at weekly intervals


Slide7 l.jpg

H.oryzaein soil as influenced by crop establishment methods


Slide8 l.jpg

H.oryzae in root as influenced by crop establishment methods


Slide9 l.jpg

Roots of freshly uprooted plant from a continuously inundated rice field


Slide10 l.jpg

Roots showing galls developed 7 days after uprooting


Slide11 l.jpg

Incidence of root-knot nematode at various moisture levels

Figures in parentheses indicate √X+0.5 transformed values


Conclusions l.jpg

CONCLUSIONS

  • Under aerobic or saturated conditions, more gall formation on the roots by root-knot nematode was observed

  • In conventional rice cultivation, H. oryzae population is more

  • In SRI fields where no water control is possible, there is need to monitor for the root nematode H. oryzae

  • Existing root knot nematode infection may not express itself, but when aerobic conditions prevail, symptoms do appear


Slide13 l.jpg

Possible impact of SRI cultivation on plant parasitic nematodes

  • Use of cono-weeder would destroy the nematodes that have invaded the roots of weed plants

  • The incorporation of weeds and organic nutrients deters movement, migration and infestation by nematode pests

  • Decomposing organic matter promotes beneficial predatory and saprophytic nematode populations


Slide14 l.jpg

Thank You


  • Login