†Central Research Institute for Dryland Agriculture, Santoshnagar, Hyderabad500059, Andhra Pradesh, India.
National Research Centre for Sorghum, Rajendranagar, Hyderabad500030, Andhra Pradesh, India.
Corn planthopper, Peregrinus maidis (Ashmead) infestation is attaining greater significance in sweet sorghum in view of its direct damage to quality and quantity of plant biomass and indirectly as a vector of several viral diseases. Eight sweet sorghum genotypes were evaluated for their reaction to planthopper infestation. Significantly low population colonization of adults and nymphs was recorded on all genotypes tested except SSV 84 and NSS 208 at 30 and 45 days. Observations recorded at 75 days showed significantly less plant damage on RSSV 09 and NSS 04, while it was high in SSV 84, BJ 248, NSS 208 and Wray. Comparison of biochemical constituents of juice estimated from infested and uninfested genotypes prior to harvest revealed that there was significant reduction of brix, sucrose and total sugars in NSS 208 and SSV 84. The corn planthopper damage expressed induction of chemical constituents in certain sweet sorghum genotypes such as NSS 04, NSS 208, and BJ 248 for reducing sugars; RSSV 09 and Madhura for total sugars and RSSV 09 for sucrose. The genotype RSSV 09 was found stable for sugar content despite being infested by the corn planthopper. The possible mechanisms of host plant resistance for population colonization were discussed.
Peregrinus maidis, sweet sorghum, plant damage, brix, sucrose content
