Journal of Biopesticides (2010) 3, 423-427

P. Chandramani, R. Rajendran, C. Muthiah and C. Chinniah (2010)
Organic source induced silica on leaf folder, stem borer and gall midge population and rice yield
Journal of Biopesticides 3 (2), 423-427
Abstract: Experiments were carried out in field conditions to analyse the effect of induced resistance on certain major pests of rice viz., leaf folder, stem borer and gall midge. The population of these insects were assessed at regular intervals on plants imposed with treatments including neem cake (NC),farm yard manure (FYM), Azospirillum (Azos), phosphobacterium (Phos), Silicate Solublising Bacteria (SSB) and lignite fly ash(LFA).The results revealed that the combination of FYM, three biofertilizers, lignite fly ash and neem cake applied in splits significantly reduced the incidence leaf folder (76.69%), stem borer (58.66 ) and gall midge (66.81%) as compared to NPK applied as inorganic form. The insect population was correlated with silica content and it was analysed in the leaf sheath and laminae of plants treated with organic sources of nutrients. As the age of the plant increased, silica content proportionately increased in the plants. There was significant difference in silica content on 45 and 60 DAT among treatments. The treatment viz., application of three biofertilizers, lignite fly ash along with FYM and neem cake either as basal (7.8%) or in splits recorded high silica content (8.10 %) as compared to other treatments. It was found that the occurrence of these major insects was negatively correlated with silica content. Correlation values between silica and insects were -0.789 for leaf folder, -0.930 for stem borer and -0.958 for gall midge. The main cause for the death of insects due to fly ash application was wearing of mandibles and main feeding organs of insects which resulted in functionless mandibles so that the insects of paddy die without food. Further, the incidence of major insects was negatively correlated with yield. Application of organic sources of nutritions significantly increased the rice grain yield. The treatment with biofertilizers, lignite fly ash, FYM and neem cake in splits recorded significantly higher grain yield (5.49 t/ha) which was on a par with NPK applied plots (5.38 t/ha).and the per cent increase in yield over NPK was 2%.It is concluded that application of organic sources of nutrition reduced the incidence of leaf folder, stem borer and gall midge and increased the yield in rice.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
damage/losses/economics

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Scirpophaga incertulas	Rice (Oryza)	India
	Cnaphalocrocis medinalis	Rice (Oryza)	India
	Orseolia oryzae	Rice (Oryza)	India