Resistensi Relatif Beras Pecah Kulit dan Beras Sosoh Lima Varietas Padi asal Banyumas terhadap Serangan Sitophilus oryzae

Abstract

The purpose of this study was to examine the resistance level of five different variety of brown rice and milled rice from Sitophilus oryzae attack during storage. Five varieties of rice that examined were Pandanwangi, Inpari 13, IR-64, Situ Bagendit, and Srikandi which all were planted in Banyumas region. This research was conducted in two experiments. The first experiment is done to measure the growth of Sitophilus oryzae during storage, while the second experiment is done to measure the rate of loss during storage. In the first experiment, 200 seeds of rice was infested by 5 couples of Sitophilus oryzae aged 7-15 days and kept for 7 days. The insects were then removed and the rice was observed every day for 14 days for emergence of the first generation (F1) of insects. The progenies were counted every day until there were no emergence for five consecutive days. The experiments were conducted in three replications. From this experiment, the parameters were number of progenies (Nt), development period (D), development index (ID), intrinsic rate of increase (Rm), and weekly multiplication capacity (λ). In second experiment, 100 g of rice infested by 25 insects and stored for 6 weeks. After 6 weeks, insects were removed and the storage loss were determined. In this second experiment, the parameters observed were percentage increase of water fraction, the loss of dry matter loss, and percentage of frass. Those two experiments were conducted in three replication. According to this experiment, Srikandi rice has the highest resistance towards Sitophilus oryzae attack among other varieties.