Author/Authors :
Suhail, Anjum University of Agriculture - Department of Agri Entomology, Pakistan , Ahmad, Jalil University of Agriculture - Department of Agri Entomology, Pakistan , Asghar, Muhammad University of Agriculture - Department of Agri Entomology, Pakistan , Tayyib, Muhammad University of Agriculture - Department of Agri Entomology, Pakistan , Majeed, M. Majid University of Agriculture - Department of Agri Entomology, Pakistan
Abstract :
The correlation between borer infestation and yield losses in order to determine the Economic threshold level (ETL) for the chemical control of rice stem borers (Scirpophaga incertulas Wlk. and Scirpophaga innotata Wlk.) was conducted at the Agronomy Research Farm, University of Agriculture, Faisalabad. The experiment was laid out in Randomized Complete Block Design (RCBD) having six levels of infestation (0%, 1%, 3%, 5%, 7%, and 9%) with four replications. Infestation levels were created by puncturing the appropriate number of tillers just above the water level with the help of dissecting needle. Mean values of grain yield obtained after harvesting (fresh weight and dry weight), percentage of unfilled grains and number of tillers varied significantly but parameters like 1000-grain weight, filled grains wt, wt of straw and plant height did not vary significantly with infestation levels. The economic analysis showed that cost of application of Padan (cartap 4.G) below 5% infestation level was more as compared to the value of reduced grain yield due to borers infestation. At 5% infestation level, the cost of chemical control was approximately equal to the yield reduction and this level can be considered as economic threshold level for rice stem borers
