Vol. 12, Issue 8 (2023)

Author(s):
PA Saravanan, V Ravichandran, P Veeramani, M Velmurugan, K Sakthivel, B Geetha and S Manickam

Abstract:
Field experiments were carried out at TCRS, Yethapur during 2021-22 and 2022-23 to monitor the mealybug infestation and to study the population dynamics of mealybug species. Phenacoccus manihoti and Paracoccus marginatus were the dominant species with population range of 0.38-4.91 nos./plant and 1.11-7.64 nos./plant respectively. The incidence of these two mealybug species was maximum during June to September months and minimum in the monsoon period i.e. October-January. Roving surveys were conducted in Salem and Namakkal districts during 2021-2023 in farmers fields at fortnightly intervals to assess the population and damage of cassava mealybug. Thalaivasal (5.6-7.0 no. of colonies/plant) and Vazhapadi blocks (5.2-7.0 no. of colonies/plant) of Salem district recorded maximum population of cassava mealybug during June to September with severe damage intensity range of 2 to 3. Namakiripettai (7.1-8.7 no. of colonies/plant) and Mallasamuthram blocks (7.2-7.7 no. of colonies/plant) of Namakkal district recorded maximum population of cassava mealybug during June to September months with severe damage intensity grade of 3 and 4.