Ramni Kumar Sarkar

Bio: Ramni Kumar Sarkar is an academic researcher from Central Rice Research Institute. The author has contributed to research in topics: Seedling. The author has an hindex of 1, co-authored 1 publications receiving 18 citations.

Seed priming in field crops: potential benefits, adoption and challenges

Abstract: Seed priming is a presowing technique in which seeds are moderately hydrated to the point where pregermination metabolic processes begin without actual germination. Seeds are then redried to near their actual weight for normal handling. Seeds can be soaked in tap water (hydropriming), aerated low-water potential solutions of polyethylene glycol or salt solutions (KNO3, KH2PO4, KCl, NaCl, CaCl2 or MgSO4; osmopriming), plant growth regulators, polyamines (hormonal priming), plant growth-promoting bacteria (biopriming), macro or micronutrients (nutripriming) or some plant-based natural extracts. Here, we review: (1) seed priming as a simple and effective approach for improving stand establishment, economic yields and tolerance to biotic and abiotic stresses in various crops by inducing a series of biochemical, physiological, molecular and subcellular changes in plants; (2) the tendency for seed priming to reduce the longevity of high-vigour seeds and improve the longevity of low-vigour seeds; (3) the advantages of physical methods of seed priming to enhance plant production over conventional methods based on the application of different chemical substances; (4) the various physical methods (e.g. magneto-priming and ionising radiation, including gamma rays, ultraviolet (UV) rays (UVA, UVC) and X-rays) available that are the most promising presowing seed treatments to improve crop productivity under stressful conditions; and (5) effective seed priming techniques for micronutrient delivery at planting in field crops. Seed priming as a cost-effective approach is being used for different crops and in different countries to improve yield, as a complementary strategy to grain biofortification and in genetically improved crop varieties to enhance their performance under stress conditions, including submergence and low phosphorus. Some of the challenges to the broad commercial adaption of seed priming include longevity of seeds after conventional types of priming under ambient storage conditions and a lack of studies on hermetic packaging materials for extended storage.

Seed priming techniques in field crops-A review

Abstract: Germination and seedling emergence are the critical stages in the plant life cycle. Insufficient seedling emergence and inappropriate stand establishment are the main constraints in the production of crops which receiving less rainfall. Farmers do not have sufficient resources to meet the requirement of seedbed preparation for sowing and they are at more risk as compared to progressive farmers. On the other hand good establishment increases competitiveness against weeds, increases tolerance to drought period, increase yield and avoids the time consuming need for re-sowing that is costly too. It is well accepted fact that priming improves germination, reduces seedling emergence time and improves stand establishment. A method to improve the rate and uniformity of germination is the priming or physiological advancement of the seed lot. The general purpose of seed priming is to partially hydrate the seed to a point where germination processes are begun, but they would exhibit rapid germination when re-imbibed under normal or stress conditions. A lot of work has been done on seed priming and results of these studies indicate well the importance of priming to get a good crop stand in many crops of tropical region such as rice, maize, sorghum and pigeon pea.

Recent Advances in Seed Enhancements

Abstract: Seed quality is vital to sustainable crop production and food security. Seed enhance‐ ments include physical, physiological and biological treatments to overcome germina‐ tion constraints by uniform stands, earlier crop development and better yields. Improved germination rates and seedling vigour are due to reduced emergence time by earlier start of metabolic activities of hydrolytic enzymes and resource mobiliza‐ tion. Nutrient homeostasis, ion uptake, hormonal regulation, activation of antioxidant defence system, reduced lipid peroxidation and accumulation of compatible solutes are some mechanisms conferring biotic and abiotic stress tolerance. Several transcription factors for aquaporins, imbibitions, osmotic adjustment, antioxidant defence and phenylpropanoid pathway have been identified. However, the knowledge of molecu‐ lar pathways elucidating mode of action of these effects, reduced longevity of primed or other physical and biological agents for seed treatments and market availability of high-quality seeds are some of the challenges for scientists and seed industry. In this scenario, there is need to minimize the factors associated with reduced vigour during seed production, improve seed storage and handling, develop high-tech seeds by seed industry at appropriate rates and integrate agronomic, physiological and molecular seed research for the effective regulation of high-quality seed delivery over next generations.

Direct Seeding in Rice: Problems and Prospects

Abstract: Rice is grown all over the world and it fulfills the dietary needs of large population across the globe. However, conventional rice production system, which involves raising of nursery seedlings followed by transplanting of those seedlings in puddled flooded soil, requires a lot of water, energy, and labor resources. Flooded rice fields are also a source of methane emission—a potent greenhouse gas. In this scenario, farmers around the world have been shifted toward water- and labor-saving direct seeding of rice. Direct seeding also reduces methane emission. In this chapter, we have highlighted issues of direct seeding of rice and have proposed strategies to uplift uptake of direct-seeded rice.