Seasonal Incidence of Major Insect Pests of Green gram in relation to Biotic and Abiotic factors in North Western Plain Zone of Rajasthan

Author: Devendra Saini, Roop Singh Meena, Udai Pal Singh, Sudhir Pratap Singh and Ashok Sakharam Chandar

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Abstract

The investigation on “Seasonal incidence of major insect pests of green gram in relation to biotic and abiotic factors in North Western Plain Zone of Rajasthan’’ was carried out at Agricultural Research Station, Sriganganagar during Kharif-2022. Whitefly and thrips were appeared soon after crop germination (second week of August) of crop. The peak population of whitefly with 63.78 whiteflies/ 3 trifoliate leaves was recorded in the fourth week of August. While, thrips attained their peak in third week of August with 14.57 thrips/ 3 trifoliate leaves. The maximum population of spotted pod borer i.e. 3.40 larvae/ 5 plant with heights pod damage 33.80 per cent was observed in second week of September. The minimum temperature and minimum-maximum relative humidity had positive correlation with whitefly and thrips population, whereas maximum temperature had negative correlation with thrips and whitefly. The total rainfall exhibited negative influence on whitefly and positive on thrips population. The spotted pod borer population and per cent pod damage had negative correlation with minimum temperature, minimum maximum relative humidity and total rainfall and positive with maximum temperature, respectively. The activity of green lacewing, Chrysoperla carnea Step., started with the infestation of whitefly and thrips in third week of August (33rd standard meteorological week). The Chrysoperla carnea Step., Cheilomenes sexmaculata Fab. and spider were major natural enemies of insect pest on crop and became active with the appearance of insect pest. The natural enemies’ population had positive correlation with minimum-maximum temperature, relative maximum humidity and pest population and negative minimum relative humidity and total rainfall.

Keywords

Seasonal, correlation, infestation, natural enemies

Conclusion

The peak incidence of whitefly was noticed in the fourth week of August and thrips attained their peak in third week of August. The whitefly and thrips population had positive correlated with all abiotic factors except maximum temperature, whereas rainfall negatively influenced the whitefly population. However, maximum incidence of spotted pod borer, Maruca testulalis Geyer with highest pod damage was observed in second week of September and negatively correlated with all abiotic factors except maximum temperature. The Chrysoperla carnea Step, Cheilomenes sexmaculata Fab and spider reported as major natural enemies of insect pest on crop and became active with the appearance of insect pest.

References

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How to cite this article

Devendra Saini, Roop Singh Meena, Udai Pal Singh, Sudhir Pratap Singh and Ashok Sakharam Chandar (2023). Seasonal Incidence of Major Insect Pests of Green gram in relation to Biotic and Abiotic factors in North Western Plain Zone of Rajasthan. Biological Forum – An International Journal, 15(10): 1698-1701.