Effect of Selected Sunshine Protectants on Persistence of Nucleopoly-hedrovirus [Hear NPV, PAU-1 Strain] against Helicoverpa armigera (Hübner) on Egyptian Clover

Persistence of the Hear NPV (PAU-1 Strain) in sunshine exposure studies on potted plants of Egyptian clover (cv. BL -10) evaluated in terms of LT₅₀ and OAR (original activity remaining) through bioassays on 2^nd instar larvae of Helicoverpa armigerr (Hübner), showed marked improvement with addition of Ranipal® (0.1%) and Jaggery (1%) in the spray suspension of the virus. The virus sprayed @ 10⁹ occlusion bodies per ml alone persisted with 13.3% OAR intact and 424 h LT₅₀ when exposed to sunshine up to 168 h (maximum exposure period tested). However, when the virus was sprayed mixed with sunshine protectants and exposed to sunshine for 168 h, it persisted longer on Egyptian clover foliage with 20.0, 26.7 and 33.3% OARs intact in case of Ranipal® (0.1%), Jaggery (1%) and a mixture of both Ranipal® (0.1%) and Jaggery (1%) Their LT_50S were however, 368, 348 and 304 h respectively. This represented significant increase in activity and persistence as compared to exposed virus alone. Jaggery appears to have also acted as phagostimulant.