I have two additional questions: What plant species were they? Have you tested paddy and shelled seeds?

Bozena Sera I am working on Indica rice seeds.

Pooja Saraswat I am sorry, but there are several additional questions:

1) Age of seeds, storage conditions.

2) Seed health. Have you tested them for pathogens? Other microbiota? There are many seed-associated bacteria with bio-herbicide effect.

3) Weather conditions before the harvest.

4) Seed treatment by any chemicals

Alex Ignatov No I have not tested any of these.

I procured an Indica rice variety from an institute for screening purposes and failed in its germination.

Pooja Saraswat

I hope it helps.

Rice Seed Invigoration: A Review

• M. Farooq et al. https://link.springer.com/chapter/10.1007/978-1-4020-9654-9_9

Part of the Sustainable Agriculture Reviews book series (SARV,volume 1)

Abstract Rice (Oryza sativa L.) provides about 55–80% of the total calories for people in South Asia, Southeast Asia, and Latin America. Elsewhere, it represents a high-value commodity crop. Change in the method of crop establishment from traditional manual transplantation of seedlings to direct seeding has been adopted in many Asian countries in the last two decades, in view of rising production costs, especially for labor and water. Seed invigoration is ascribed to beneficial treatments, applied to the seeds after harvest but prior to sowing, that improve germination or seedling growth or facilitate the delivery of seeds and other materials required at the time of sowing. Many seed invigoration treatments are being employed in a number of field crops, including rice, to improve seedling establishment under normal and stressful conditions. The treatments used to invigorate rice seed include hydropriming, seed hardening, on-farm priming, osmopriming, osmohardening, humidification, matripriming, priming with plant growth regulators, polyamines, ascorbate, salicylicate, ethanol, osmolytes, coating technologies, and more recently presowing dry heat treatments. In the wake of the day-to-day increasing cost of labor and shortage of water, direct seeding approaches in rice cropping systems are the subject of intensive investigation throughout the world and offer an attractive alternative to traditional rice production systems. In this regard, seed invigoration techniques are pragmatic approaches to achieving proper stand establishment in the new rice culture. They help in breaking dormancy and improving seedling density per unit area under optimal and adverse soil conditions. Induction and de novo synthesis of hydrolases, such as amylases, lipases, proteases; and antioxidants such as catalases, superoxide dismutase and peroxidases are reported to be the basis of improved performance using these techniques. The rice seed priming can be performed by soaking simply in water, a solution of salts, hormones, osmoprotectants, matric strain-producing materials, and other nonconventional means. Despite certain limitations, such as water potential, oxygen and temperature, rice seed invigoration has been worthwhile in improving rice yield and quality. Nevertheless, in-depth studies are imperative for understanding the physiological and molecular basis of rice seed priming.

Use the red tetrazole solution to dye the embryo of a hulled paddy seed, if the embryo shows no red color, the seed is dad seed.