Author(s)

Yoshihiro Nakao¹, Godfrey Asea², Minoru Yoshino³, Nobuki Kojima^3,4, Hiroyuki Hanada⁴, Kisho Miyamoto⁴, Shin Yabuta⁵, Rieko Kamioka⁴, Jun-Ichi Sakagami^5*

¹The United Graduate School of Agricultural Sciences Kagoshima University, Kagohsima, Japan.
²National Crops Resources Research Institute, Kampala, Uganda.
³Japan International Cooperation Agency, Tokyo, Japan.
⁴Appropriate Agriculture International Co. Ltd., Tokyo, Japan.
⁵Faculty of Agriculture Kagoshima University, Kagoshima, Japan.

Hydropriming is one of the presoaking, seed priming technique that allows seeds to imbibe water and go through the first stage of germination but does not allow radicle appearance. After water imbibition, seeds are dried to their original weight. This technique is used to help crops overcome environment stress. This study aims to assess the morphological traits of farmer’s seeds for developing priming treatments so as to develop appropriate methods to maximize the effect of hydropriming. We collected farmer’s samples of rice sowing seeds grown indifferent regions of Ugandan. For each sample, distribution of the seed density in percentages was calculated. Secondly, germination tests as per seed density levels and as per farmer’s seed samples were conducted for deciding appropriate priming treatment. Finally, wooden boxes experiment was conducted to confirm priming effects. As the result, it was observed that the difference in seed density levels affects the quality of farmer’s seeds, as observed in the case of NERICA4. If the radicle appears during soaking period, the newly developed radicle dies during the seed drying process in the hydropriming treatment. Seed germination was observed after 24 h of sowing at room temperature, even at a seed density level of 1.17, which is vigorous for germination. Consequently, farmer’s seeds were soaked for 24 h to promote water absorption and activate metabolic pathways and to avoid germination failure when seeds are dried to their initial weight. After hydropriming treatment, plant growth was improved. Alternatively, significant difference was not observed in the mean emergence time between hydroprimed and unprimed seeds. These results suggest that priming the seeds by soaking for 24 h and drying to their initial weight considerably affects initial growth after emergence under dry soil condition.

Rice, Priming, Germination, Emergence, Seed

Nakao, Y., Asea, G., Yoshino, M., Kojima, N., Hanada, H., Miyamoto, K., Yabuta, S., Kamioka, R. and Sakagami, J. (2018) Development of Hydropriming Techniques for Sowing Seeds of Upland Rice in Uganda. American Journal of Plant Sciences, 9, 2170-2182. doi: 10.4236/ajps.2018.911157.