EVALUATION OF PHYTOSOCIOLOGICAL, NATURAL REGENERATION AND SITE CHARACTERISTICS OF Rhododendron campanulatum D. Don IN ALPINE REGION OF WESTERN HIMALAYAS
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Date
2020-08
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UHF,NAUNI
Abstract
ABSTRACT
The efficacy of Metarhizium(=Nomuraea) rileyi (Farlow) Kepler, S.A. Rehner and
Humber was studied against different larval instars of Helicoverpa armigera (Hubner) by
larval dip method. M. rileyi when applied against different larval instars of H. armigera at
concentrations between 102-108 conidia/ml resulted 20-96.67, 16.67-93.33, 20-83.33, 16.67-
76.67 and 13.33-53.33 per cent mortality of 1st, 2nd, 3rd, 4th and 5th instar larvae, respectively.
LC50 and LC90 values for different instars were 5.51 x 103, 6.87 x 104, 2.81 x 105 and 5.55x
105 ; and 2.86 x 106, 1.56 x 107, 1.72 x 109 and 2.87 x 109 conidia/ml against 1st, 2nd, 3rd and
4th instar larvae, respectively. M. rileyi at 107 conidia/ml took 5.48, 6.26, 8.16 and 8.44 days
to kill 50 per cent and 10.19, 9.88, 13.91 and 14.39 days to kill 90 per cent of 1st, 2nd, 3rd and
4th larvae of H. armigera, respectively. Azadirachtin (1.02ppm), azadirachtin (1.53ppm) and
indoxacarb (0.72ppm) inhibited the growth of M. rileyi by 47.31, 62.47 and 72.39 per cent,
respectively. However, M. rileyi at concentrations of 102 to 107 conidia/ml mixed with
azadirachtin (1.02ppm) and indoxacarb (0.72ppm) and tested against second instar larvae
resulted 10.34-96.55 (LC50: 1.09 x 104, LC90: 2.39 x 106 conidia/ml) and 14.29-92.86 per cent
(LC50: 1.37 x 104, LC90: 6.73 x 106 conidia/ml) mortality, respectively. Similarly M. rileyi at
concentrations of 103-108 conidia/ml impregnated with azadirachtin (1.53ppm) and
indoxacarb (0.72ppm) tested against third instar larvae resulted 13.79-89.66 (LC50: 2.79 x
103, LC90: 3.12 x 108 conidia/ml) and 14.29-92.86 (LC50: 3.06 x 105, LC90: 1.11 x 109
conidia/ml) per cent mortality, respectively. M. rileyi (107 conidia/ml) alone or conidial
suspension mixed with azadirachtin (1.02 and 1.53ppm) and indoxacarb (0.72ppm) resulted
non-significant effect on days to mortality of 2nd and 3rd instar larvae of H. armigera. Hence
M. rileyi can be used as one of the component of IPM programme for eco-friendly
management of H. armigera after field evaluation.