Kajian Resistensi Lima Varietas Sorgum terhadap Rhyzopertha dominica (F.) (Coeloptera: Bostrichidae).

Abstract

Sorghum is a cereal crop source of carbohydrate that can be used as a substitute for rice. Sorghum seed storage facing many problems caused by stored product pest, one of them is Rhyzopertha dominica (F.). Damage to sorghum seed caused by insect pests reach 30%. The objective of this research was to evaluate the resistance of five sorghum varieties against R. dominica during storage. Research was conducted at Entomology Laboratory SEAMEO- BIOTROP. Bioassays were conducted by infesting 40 adults of R. dominica to 1000 ml plastic jar containing 100 g sorghum seed for 14 days and then taken out from the jars. All the jars, then incubated for 42 days. Five sorghum varieties tested were Numbu, local Bandung , Local Wonogiri, CTY-33, and B-76. Between day 42-80, all F1 adults came out from the seeds were counted. Resistance level then determined by Dobie Index of Susceptibility (DIS). Weight loss from each variety were also calculated. Research result showed that CTY-33 was the most resistant variety with DIS value of 3.814, seed hardness seemed to be the resistance factor.