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S. K. Pedda Ghouse Peera ¹, P. Balasubramaniam ², M. Raghavendra Reddy ³, P. Chandramani ⁴

Affiliations
1 Agricultural College (ANGRAU), Bapatla (A.P.), IN
2 Agriculture College and Research Institute (T.N.A.U.), Coimbatore (T.N.), IN
3 University of Agricultural Sciences, GKVK, Bangalore, (Karnataka), IN
4 Agriculture College and Research Institute (T.N.A.U.), Madurai (T.N.), IN

Abstract

Field experiments were conducted to investigate the effect of graded levels of fly ash with silicate solubilizing bacteria (SSB) and FYM on the incidence of rice stem borer (Scirpophaga incertulas) (Lepidoptera: Pyralidae) in rice crop in low and high Si soils under Split Plot Design. The graded levels of fly ash incorporated in soil at five levels (0, 25, 50, 75 and 100 t/ha) one week before crop transplantation. The results of field experiment in low Si soil showed that fly ash had significant influence on the stem borer population over the control. On an average, with respect to borer incidence, higher dose of fly ash @ 100 t ha^-1 markedly decreased infestation (16.9 %) while, applications at 25 and 50 t ha^-1 permitted slightly more dead hearts incidence, but differed significantly from control. In main plot treatments, application of SSB + FYM recorded 16.1 per cent of stem borer incidence. Application of fly ash @ 100 t ha^-1 with SSB + FYM reported less per cent of dead hearts. In high Si soil, the effect of main treatments and interaction effect was non-significant. However, application of fly ash @ 100 t ha^-1 had significant effect with meagre pest incidence of 11.6 per cent. Besides application of SSB and SSB+FYM alone played a major role in maintaining ETL of stem borer. The present study implies that due to suppressive effects of Si and K present in fly ash the incidence of the rice stem borer mitigated at crop vegetative stage and the use of soil incorporation strategy can create an unfavourable condition for pests to survive.

Keywords

Rice, Scirpophaga incertula, SSB, Fly Ash.

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V. S. Indhumathi ¹, P. Chandramani ², J. Jayaraj ³, C. Chinniah ¹, P. P. Mahendran ¹, K. Kumutha ¹

Affiliations
1 Tamil Nadu Agricultural University, Agricultural College and Research Institute, Madurai – 625104, Tamil Nadu, IN
2 Tamil Nadu Agricultural University, Agricultural College and Research Institute, Kudumiyanmalai – 622104, Tamil Nadu, IN
3 Tamil Nadu Agricultural University, Grapes Research Station, Theni – 625526, Tamil Nadu, IN

Abstract

To evaluate the effect of four silicon fertilizers, field experiment was conducted in farmer’s holding at Poovanthi village of Sivagangai district, Tamil Nadu during 2017-2018 against sugarcane leaf hopper, Pyrilla perpusilla Walker and its parasitoid, Epiricania melanoleuca (Fletcher). Silicon fertilizers were applied @ 500 and 1000 kg ha^-1 before planting and the leaf hopper population was recorded at 150, 180, 210, 240 and 270 days after application. The results of field experiment revealed that Pyrilla population was minimum in the plots treated with calcium silicate @ 1000 kg ha^-1 (8.20 numbers/leaf) followed by calcium silicate @ 500 kg ha^-1 (8.80 numbers/leaf) as compared over untreated check (98.20 numbers/leaf) and the percent reduction over untreated check was 82.45 and 73.71 per cent, respectively. Similarly, the per cent parasitism was maximum in the treatment with calcium silicate @ 1000 kg ha^-1 (82.33%) during November, which was on par with untreated check. Hence, Pyrilla population declined to an extent of 82.45 per cent by enhancement of E. melanoleuca parasitism (82.33 %) due to the application of silicon fertilizers.

Keywords

Epiricania melanoleuca, Parasitism, Pyrilla perpusilla, Silicon Nutrition.

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