Damage potential of the spider mite Tetranychus ludeni (Acari: Tetranychidae) on four varieties of eggplant
2006
Reddy, G. V. P. | Baskaran, P.
The damage potential of the spider mite Tetranychus Indent Zacher was studied on 20-65-day-old seedlings of four eggplant Solanum melongena varieties: Madurai (MDU₁), Coimbatore (CO₁), Annamalai and Panruti at introduction levels of 2, 5, 10 and 15 mites/leaf. The average seedling mortality among varieties was lowest at the introduction level of two mites and maximum at the introduction level of 15 mites/leaf. The overall seedling mortality was 23% when the four levels of mite population were introduced on 20-day-old seedlings, and only 14% on 30-day-old seedlings. Among the different varieties, the MDU₁ seedlings recorded higher mortality (1.6%) and Panruti the lowest (0.3%). The percentage losses in total plant height, number of leaves, number of flowers and fruits and fruit weight due to mite attack were highest (37–50%) in MDU₁ and lowest (7–11%) in the variety Panruti. The other two varieties CO₁ and Annamalai were found to be intermediate between Panruti and MDU₁. The inoculated mites at different levels multiplied greatly on the variety MDU₁ followed by CO₁, Annamalai and Panruti. The extent of damage was higher in 35-day-old plants, when mites were introduced on 35- and 65-day-old seedlings. Therefore, the variety Panruti is recommended for cultivation in the study area in view of its resistance to T. Indent.
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