An overview of seed enhancement technologies for sustainable agricultural production

Abstract

Seed is regarded as a dynamite for change and carrier of new technologies. Hence, it needs to be protected and preserved so that it can act as an effective and efficient vehicle for the delivery of such technologies. Various treatments have been used in many crops for a variety of purposes since ages. Treatments that control seed borne pathogens using conventional crop protection chemicals are considered as 'seed treatments', whereas 'seed enhancement' is the term used in scientific literature and seed industry to describe the range of beneficial techniques performed on the seeds after harvest, but prior to sowing through manipulation of physiological status for better planting value, improved germination and uniform seedling growth. Sorting on the basis of size, colour, chlorophyll content and X-ray analysis of internal structures or buoyant density in solvents offer the ability to remove weak or dead seeds, resulting in up-gradation of quality quality seed lots. Seed enhancement includes priming, steeping, hardening, pre-germination, pelleting, encrusting, film-coating etc. Hydration is perhaps one of the primitive methods to manipulate vigour or physiological status of seed, while enhancements like pelleting, coating and encrusting improve seed handling and precision planting. Both priming and coating technologies can also deliver beneficial microorganisms through seed. Some treatments enhance nutrient availability or provide inoculants (other than pesticides) required to improve germination and seedling establishment. Rhizobium inoculation of legume seeds is an efficient and convenient way of introducing effective rhizobia to the soil and subsequently into the rhizosphere. Other treatments may include the use of chemicals that trigger systemic acquired resistance or help to tolerate stress. Organic farming market standards are stimulating the evaluation and optimization of methods to produce healthy planting material and new seed sanitation treatments as alternatives to fungicides or conventional hot water or bleach treatment while retaining seed viability in storage. The advancement in technologies for improving planting value of seed will continue to usher in enhanced agricultural production. This paper tries to review the uses of range of 'seed enhancement technologies' that could be adapted as a cultural package, including latest techniques and approaches that may aid in commercial application and utility to boost early seedling vigour abetting per unit higher productivity.