The economic effects of Rhyzopertha dominica on rice quality: Objective and subjective measures

Authors: SU, LIANFAN - Signifyd Corporation; ADAM, BRIAN - Oklahoma State University; Arthur, Franklin; LUSK, JAYSON - Purdue University; MEULLENET, JEAN - University Of Arkansas

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2019
Publication Date: 9/4/2019
Citation: Su, L., Adam, B.D., Arthur, F.H., Lusk, J.L., Meullenet, J.F. 2019. The economic effects of Rhyzopertha dominica on rice quality: Objective and subjective measures. Journal of Stored Products Research. 84:101505. https://doi.org/10.1016/j.jspr.2019.08.002.
DOI: https://doi.org/10.1016/j.jspr.2019.08.002

Interpretive Summary: The lesser grain borer can cause extensive damage to stored grains, including rough rice or paddy rice. Although economic effects of infestations have been documented, there are few studies regarding quality impacts or consumer preferences for stored rice that is managed to control this insect versus rice that has a history of infestation. We conducted studies by artificially infesting rice with two levels of lesser grain borer infestation, termed low and high, milled the rice, and compared quality characteristics of the rice and consumer preferences with uninfested rice. We documented a quality and value loss for both levels of infestation. Consumers were initially willing to pay only a small increase in price for the uninfested rice, but when given extra information, they were willing to pay a much higher price, thereby demonstrating the value of improved insect pest management. Our results show that consumers will pay more for higher quality, but rice sellers must be able to educate their customers in regards to the information and data regarding improved rice storage management.

Technical Abstract: Infestations of internal feeders such as Rhyzopertha dominica cause damage to stored grains, including rice. Few studies, though, have measured the economic effects of that damage. In this study, samples of rough long grain rice were infested with R. dominica at several rates. The effects of these infestations on rice quality and quantity were measured objectively using color and milling yield. They were also measured subjectively with a blind taste/sensory consumer taste test and a non-hypothetical auction measuring consumer willingness to pay for the different qualities of rice. The objective quantity and value loss ranged from 2% for lightly-infested rice to 3.5% for heavily-infested rice. For subjective effects, results of the auction suggested that participants on average were willing to pay only a small premium for less infested rice. This test confirmed results of the sensory taste panel, which showed that participants on average detected very little difference among rice samples with alternative levels of infestation. However, when they were given extra information verifying that rice with lower infestation levels was higher quality or that the rice was stored using IPM methods, the potential price increase from reducing R. dominica infestation could range from $0.44/kg. to $0.79/kg., plus a $0.13/kg. premium for using IPM storage methods. However, results show that in order to capture that value rice sellers must be able to convey information about quality and storage attributes to consumers in a way that is relevant and trustworthy.