To substantiate the hypothesis that HCP can provide benefit to rice germination, we irradiated 100 rice seeds with hybrid plasma for 1 min using the same protocol described for the hydrophilic treatment conditions. We placed 100 treated seeds and another 100 nontreated seeds on moist seed-germination paper kept in transparent acrylic seed-germination trays. Each
tray contained ∼25 rice seeds (total ∼8 trays). The experiments were repeated four times under the same setup conditions to confirm the reproducibility of processes. We used seeds of Oryza sativa var. Indica cv. KDML105 that were kept in a clean polyethylene box under ∼10% relative humidity. During the plasma treatment, we randomly chose ∼20% of the total treated seeds and performed contact-angle measurements to ensure the successful hydrophilic enhancement of the seeds and also the uniformity and reproducibility of the plasma-treatment process.All of the samples were incubated in Plant Growth Chambers (Daihan Labtech Model LGC-5201) at 20 °C in the dark for 16h and 30 °C in cool light for 8 h. The controlled relative humidity was ∼85% (see the Experimental Section). We examined the seeds every 24 h and considered them germinated when the radicle emergence was ∼0.5 cm. We calculated the maximum germination percentage by counting
the seedlings on days 7 and 14.29 Figure 4 shows the overall results for the treated and nontreated seedlings after day 14.During the first 7 days, the average radical emergence
percentage was ∼98% for treated and ∼90% for nontreated seeds. However, there was no significant difference of the seedling length between the nontreated and treated rice seeds.
The average seedling length of both condition was ∼4.3 cm.