Browsing by Author "HARISH BABU, S"

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    ThesisItemOpen Access
    DEVELOPMENT AND EVALUATION OF INTEGRATED PEST MANAGEMENT (IPM) INTERVENTIONS AGAINST MULBERRY LEAF ROLLER, Diaphania pulverulentalis (HAMPSON) (LEPIDOPTERA: PYRALIDAE)
    (UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2015-09-08) HARISH BABU, S; Narayanaswamy, K. C
    An integrated pest management package was standardized under laboratory condition and tested in farmers’ fields against mulberry leaf roller, Diaphania pulverulentalis (Hampson), a major defoliating pest of mulberry in tropical parts of the country. NSKE (4 %) was significantly superior to five other neem formulations against larvae of D. pulverulentalis under laboratory conditions. LT50 values for D. pulverulentalis larvae treated with different concentrations of NSKE (i.e., 0.5, 1.0, 2.0, 4.0 and 8.0 %) were significantly different, ranging between 1.06 to 5.27 days. NSKE at 1.0, 2.0, 4.0 and 8.0 percent had maximum adverse effect on D. pulverulentalis development and survival, with minimum LC50 value (946.38 ppm). Laboratory bioassay proved that feeding silkworm with NSKE (4 %) treated leaves on 22nd days after spray was safest by recording lowest silkworm mortality (2.11 %), without affecting economic parameters of silkworm. The egg parasitoid, Trichogramma chilonis recorded higher parasitization on one-day-old eggs of D. pulverulentalis (90.84±1.18 %), compared to two (90.00±0.00 %) and three-day-old eggs (72.50±5.90 %), while, pupal parasitoids, Tetrastichus howardii and Nesolynx thymus showed 86.67 and 13.33 percent parasitization, respectively on pre-pupae of D. pulverulentalis. Similar trend was also observed even on pupae. However, T. chilonis was more efficient than the pupal parasitoids. The LC50 of DpNPV for D. pulverulentalis was 0.591 ppm, while the LT50 was 3.04 days when caterpillars were fed with mulberry leaf treated with highest DpNPV load of 27.65×105 PIBs/ml, besides registering maximum mortality during fifth instar, prolonged early larval and moulting periods and hindering completion of fourth moult. The IPM module (4 % NSKE spray at 15 to 20 days after pruning (DAP) + DpNPV @ 27.65×105 PIBs/ml at 25 to 30 DAP + release of T. chilonis @ 1 lakh/acre at 45 to 50 DAP) recorded significantly lower pest infestation of 11.55 per cent compared to chemical control (19.04 %), at 65 DAT, besides registering higher cost-benefit ratio (1:7.14) than chemical control (1:4.70). Feeding the mulberry leaves from IPM treated plots had no negative impact on growth and productivity of silkworm (PM×CSR2) thus proving silkworm-friendly and cost- effective nature of IPM.
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    ThesisItemOpen Access
    IN VITRO AND IN VIVO EFFICACY OF ALOE VERA (L.) N. BURMAN IN MANAGEMENT OF BACTERIAL FLACHERIE OF SILKWORM, BOMBYX MORI L.
    (UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2009-07-10) HARISH BABU, S; FATIMA, SADATULLA
    Studies on the influence of In-vitro efficacy of Aloe vera gel leaf extract on inhibition zone of Bacillus sp. and In-vivo efficacy of Aloe vera gel extract administered with Bacillus sp. and administration of only Aloe vera gel extract on larval growth, development and economic traits of silkworm, were conducted during 2008-09. In-vitro efficacy of Aloe vera gel on inhibition zone of Bacillus sp. revealed significant results against raw gel and sterilized gel. The maximum zone of inhibition was found in 100 and 75 per cent Aloe vera gel extracts followed by 50 and 25 per cent compared to control against raw gel batch. Whereas, no zone of inhibition was observed in sterilized gel batch of the above mentioned concentration. The silkworm (PMxCSR2) reared on mulberry leaves smeared with Aloe vera gel extract of 100 per cent concentration at 10-3 bacterial spore dilution had effective enhancement of larval weight (3.24g), ERR (94.50%), cocoon weight (1.89g), shell weight (0.327g), pupal weight (1.559g), shell ratio (17.29%), silk productivity (4.19 cg/day) and filament length (853.77m) besides reduced larval duration (7.80 days) and disease incidence (9.20%) when compared to 10-2 and 10-1 bacterial spore dilution and control. Similarly, silkworms reared on mulberry leaves smeared with Aloe vera gel extracts also exhibited significant differences with respect to In-vivo studies. However, larval weight (3.40g), ERR (96.37%), cocoon (1.93g), shell (0.340g) and pupal weights (1.59g), silk productivity (4.45 cg/day) and filament length (903.94m) were significantly maximum in 100 per cent Aloe vera gel extract, besides reduced larval duration (7.62 days) and disease incidence (3.62%) compared to other treatments and control. Among the concentrations, 100 per cent concentration showed significantly higher values for larval and cocoon traits compared to 75, 50 and 25 per cent concentrations. Among the bacterial spore dilutions 10-3 bacterial spore had effective enhancement of larval and cocoon parameters compared to 10-2 and 10-1 bacterial spore dilutions.