Effects of Plasma Focus on Seed Germination and Seedling Growth of 14 Thai Rice Varieties

Thailand Plasma Focus 2 (TPF-2) is operated at 2.16 kJ of storage energy with argon as a filled gas and can emit sharp x-ray pulses to plant cells in nanosecond (10-9 s) duration. The effects of plasma focus x-ray on seed germination and seedling growth of 14 Thai rice varieties treated under 10 conditions; 0 (control), 2, 4, 6, 8, 10, 12, 14, 16, and 18 plasma focus shots, were investigated. The results show that the germination rates and growth reduction rates were significantly different among the rice varieties. The germination rate of 10 varieties (Jek Chuey, KDML105, LPT123, PTT1, RD41, RD47, RD49, RD67, RD79, and SPR2) decreased when treated with a high number of plasma focus shots. LD50 and GR50 values were calculated, except for KTH17, RD1, RD7, and RD31 whose germination only slightly decreased, or remained constant, even after they were treated by 18 plasma focus shots. HIGHLIGHTS Effects of plasma focus irradiation on germination and growth were assessed on 14 Thai rice varieties  Shoot and root lengths of rice seedlings were measured 10 days after of plasma treatment Plasma focus was operated at 12 kV and the number of plasma focus shots was varied from 0 (control) to 18 shots Sensitivity to plasma irradiation was found to differ among rice seeds tested GRAPHICAL ABSTRACT