Efficacy of Insecticides on Rice Crop Against Rice Leaf Folder, Cnaphalocrocis Medinalis Guen. (Pyralidae: Lepidoptera)

Abstract

A field study was carried out during 2010 at experimental area Sindh Agriculture University Tandojam in RCBD to examine the reduction percentage in the population of C. medinalis on rice crop with three insecticides viz; Deltophos, Tracer, Thioluxan and impact of these insecticides was composed with control plot (untreated). The data showed the maximum reduction (76.19%) in the population of C.medinalis was recorded in the plots treated with Deltaphos followed by Tracer (65.93%) and Thioluxan (46.92%) after 1^st spray on rice crop. In the second spray maximum reduction (71.08%) was also recorded in the plots treated with Deltaphos followed by Tracer (57.40%) and Thioluxan (30.15%). Similarly, after 3^rd spray the maximum reduction (78.99%) was recorded in the plots treated with Deltaphos followed by Thioluxan (55.88%) and Tracer (54.34%) on rice crop. While, in fourth spray, the maximum reduction (71.92%) was recorded in plots treated with Deltaphos followed by Tracer (39.36%) and Thioluxan (14.36%) on rice crop. The results further indicated that the maximum yield (4783.00kg/ha?1) was recorded in plots treated with Deltophos followed by Tracer (4486.46kg/ha ?1) and  Thioluxan (4033.66kg/ha?1) as compared control (3066.50kg/ ha?1).Highly significantly (P < 0.01) difference in the efficacy of insecticides was recorded during all sprays carried out in cropping season of rice crop.

Key word: Oryza sativa, Cnaphalocrocis medinalis. Management and Insecticides.