Management of Stem Borer, Chilo Partellus (Swinhoe) in Maize Through InundativeRelease of Trichogramma Chilonis Ishii

摘要

Inundative release of Trichogramma chilonis @ 1,00,000/ha at weekly interval starting from 20 DAE in maize (hybrid - 30V92) was evaluated in a farmers' fields during rabi seasons of2009-10 and 2010-11. Parasitoid released plots and chemical control plots were at par in recording shot hole damage (9.3 and 7.7 %), dead hearts (3.2 and 2.5%), C. partellus larvae (1.8 and 1.2/ plant) at 50 DAE and stem tunneling at harvest (22.3 and 18.4%) and were significantly superior than untreated control (19.6% shot hole, 10.8% dead hearts, 31.1% stem tunneling) and larval population (4.5 / plant). Similar trend in stem borer incidence was continued during rabi 2010-11. Two year mean grain yield in parasitoid release treatment (66.0 q/ha) and chemical control (73.5 q/ha) fields were at par, whereas, it was significantly lower in untreated control (43.7 q/ha). The net profit over control during rabi 2009-10 and 2010-11 in biocontrol package was Rs. 22125/- and Rs. 23780/- per ha as compared to Rs. 27745/- and 30095/- per ha in farmers' practice with cost benefit ratio of 1:20.5,1: 22.0,1:8.9 and 1: 9.6, respectively.