Source: SEAMEO BIOTROP's Research Grant | 2012
Abstract:In Indonesia, sorghum is less developed potential food sources and only becomes the fourth choices as carbohydrate source after wheat, rice, and corn. During storage Rhyzopertha dominica and Sitophilus zeamais are the most destructive pests of sorghum grains. Developing resistance of sorghum grains against those pests can be expected to overcome that problem. Resistance test of five varieties of sorghum grains was conducted in by infesting forty adults of R. dominica and S. zeamais with homogenous ages (1-14 days) into 1000 ml plastic jars contain 100 g sorghum seeds. Two weeks and after that all adult insects were taken out from the jars and incubations then continued until the first adult of their offspring were emerged. Parameters observed were numbers of F1 adults emerged, median development time, seeds weight lost, seed dimension and hardness, and tannin and phenol content of sorghum seeds. Resistance level was calculated based on Dobie Index of Susceptibility (DIS). All parameters then correlated with DIS using Pearson Correlation Test. In general, five sorghum varieties tested showed more resistant to R. dominica than to S. zeamais. Among the varieties tested Numbu was relatively more to S. zeamais (DIS value 6.99) and CTY-33 was relatively more resistant to R. dominica (DIS value 3.81). Resistance levels of these varieties were more affected by tannin and phenol contents than seed dimensions.
Key words: sorghum, numbu, local bandung, local wonogiri, cty-33, b-76, resistance, rhyzopertha domonica, sitophilus oryzae.
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