Effects of acoustic frequency technology on rice growth, yield and quality

Abstract: To know the effects of acoustic frequency technology on rice growth, yield formation, and quality, the field experiment was carried out in the China National Rice Research Institute. The Tianfengyou 5 which belongs to the indica type hybrid rice and Yongyou 13 which belongs to the japonica type hybrid rice were taken as test cultivars. Split plot design was used with cultivars in the main plots and acoustic frequency treatment (AFT) and control (CK) in the sub-plots. The plots, each 100 m2 were repeated 4 times. The acoustic frequency generator developed by Zhejiang University of Science and Technology was used in AFT to regulate the acoustic wave. This acoustic frequency generator was a kind of autoplay and autocontrol system, it could play the classical music and mixed sound of birdsong and cricket song. The main frequency of AFT was about 50 Hz, and ranged from 300 to 6000 Hz, and the audio loudness was about 80 dB. The playing time was designed by the programmable timer. From rice transplanting stage to 5 days before harvest stage, the acoustic frequency generator broadcasted everyday and lasted 3 hours (08:30-11:30).The results showed that the rice yield of AFT for Tianfengyou 5 and Yongyou 13 was 5.11% and 5.38% higher than that of CK, respectively. And the yield differences between AFT and CK for these two cultivars were significant. Compared with CK, the AFT increased the rice tillers of the early growth period. After 7 days (Sep. 8) and 14 days (Oct. 6), the average tillers per hill of Tianfengyou 5 for AFT were 0.3 and 0.5 higher than that of CK, respectively, and the average tillers per hill of Yongyou 13 for AFT were 1.1 and 1.0 higher than that of CK, respectively. Compared with CK, the effective panicle number of AFT for Tianfengyou 5 and Yongyou 13 were increased 8.40 panicles/m2 (3.88%) and 5.80 panicles/m2 (3.33%), respectively. Compared with CK, the average filled grains per panicle of AFT for Tianfengyou 5 and Yongyou 13 were increased 2.46 grains (1.45%) and 4.46 grains (1.71%), respectively. The increasing effective panicles number and filled grains became dominant factors of high yield. Compared with CK, the SPAD of AFT for Tianfengyou 5 in booting stage (Sep. 8) and grain filling stage (Oct. 6) were 11.36% and 10.41% higher than that of CK, respectively; and the SPAD of AFT for Yongyou 13 in booting stage (Sep. 22) and grain filling stage (Oct. 20) were 5.20% and 4.91% higher than that of CK, respectively. The AFT significantly improved the rice qualities. Compared with CK, the rice transparency of AFT for both Tianfengyou 5 and Yongyou 13 were improved 1 grade, the chalkiness of AFT for Tianfengyou 5 and Yongyou 13 was decreased by 21.31% and 5.88%, respectively, the gel consistency of AFT for Tianfengyou 5 and Yongyou 13 was increased by 2.0 and 8.0 mm, respectively, the head rice rate of AFT for Tianfengyou 5 and Yongyou 13 was increased by 6.99% and 2.22%, respectively, the rice quality index for Tianfengyou 5 and Yongyou 13 was increased by 6.58% and 10.94%, respectively. These indictors all improved the rice qualities.