Effects of Infrared Radiation on Germination of Long Grain Rice

Abstract

HighlightsThe study provides insight to infrared (IR) drying and the effects on germination of two long-grain rice cultivarsDrying rice seeds using IR with intensity at 10.84 kW/m2 negatively impacted germination and probabilities of shoot and primary root growth.IR intensities of 2.15 and 2.83 kW/m2 did not affect rice seed germination or growth compared to control samples dried using natural air at 26°C and 65% relative humidity.CL152, the pureline cultivar, did not germinate as well as XL745, the hybrid cultivar.Abstract. Infrared radiation (IR) can effectively dry rice; however, the effects of IR on germination need to be determined. We compared the effects of natural air drying and three IR-drying intensities (2.15, 2.83, and 10.84 kW/m2) on rice germination for two rice cultivars, XL745 (hybrid) and CL152 (pureline). Although lower for CL152 than for XL745, the probability of germination was lowest after IR-drying at 10.84 kW/m2 for both cultivars. The probability of shoot or root growth was also lowest for kernels treated at 10.84 kW/m2; however, cultivar was the only factor included in the best model for predicting shoot and root length, suggesting that the range of IR intensity tested does not affect shoot or root length. Treatment of rice with an initial moisture content of 20% w.b. with an IR intensity of 10.84 kW/m2 for 7 s reaching a temperature of 60°C is not recommended for use on rice that will be used for seed grain; lower IR intensities appear more appropriate. Keywords: Germination, Hybrid rice, Infrared drying, Pureline rice.