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This book entitled “Post Harvest Handling and Storage of Seeds” will cover the topics in detail in terms of seed drying, seed processing, storage, in addition to seed de-linting, seed blending, physical, physiological and chemical changes during seed storage, seed extraction of vegetable crops packaging, seed storage insects and pests and its management. Here are the glimpses of the contents that has been divided into several parts which will be included in this volume of the book. Seed processing plays a crucial role in modern agriculture by ensuring the availability of high-quality seeds that contribute to increased crop productivity, improved resilience to environmental stress, and enhanced food security. Seed storage structures play a crucial role in preserving the genetic diversity of plant species, ensuring food security, and supporting agricultural sustainability. Seed grading involves sorting seeds based on various characteristics such as size, shape, weight, purity, and germination rate. The grading techniques plays a crucial role in ensuring the quality, uniformity, and viability of seeds, ultimately contributing to successful crop production and agricultural sustainability. The principles of seed storage are crucial for maintaining the viability and quality of seeds over time. It helps in preservation of genetic diversity, maintenance of viability, conservation of rare and endangered species etc. Assessing physical, physiological, and biochemical changes during seed storage is fundamental for maintaining seed viability, ensuring seed quality, predicting longevity, optimizing storage conditions, preserving genetic diversity, ensuring quality control, and driving research and development efforts in seed conservation and management. Seed drying is a crucial process in agriculture and seed preservation, aimed at reducing the moisture content of seeds to a level that minimizes the risk of microbial growth and seed deterioration. Seed de-linting is a crucial step in the seed processing industry, especially for cotton seeds. By de-linting seeds and assessing mechanical damage, seed producers can ensure the delivery of high-quality seeds to farmers, thereby maximizing crop yield and profitability. Packaging plays a crucial role in maintaining seed quality and longevity, as well as facilitating proper handling and storage.

Concept: Operations conducted before and after harvest are essential components of the system for producing high-quality seeds. If enough care is not taken in the initial stage, there most likely won’t be any resources left to get high-quality seed. Like this, carefully produced, high-quality seed may lose a significant percentage of its worth if post-harvest management protocols are not adhered to. Its quality is highly correlated with soundness, fullness, and homogeneity of physical characteristics (size, shape, density, colour, and appendages), in addition to mechanical planting’s simplicity and improved crop establishment. Improving the seed that has been gathered and getting it ready for secure storage till needed are accomplished through the effective and efficient process of seed processing. To increase the quality of the seed lot, the goal of seed processing must be to optimize the physical properties of the seed and the constituents of the harvested seed mass. The three main steps in seed processing are conditioning, grading, and applying protectants or enriching with nutrients. These steps are completed in compliance with established protocols and standards (McDonald and Copeland 1997; Agrawal 1996; Jorgensen and Stevens, 2004). The distinct qualities of the crops and the surroundings are taken into consideration while adjusting the machines and operations.

Concept: The preservation of viable seeds from the moment of collecting until they are needed for sowing is known as storage. Every year, a significant quantity of seeds loses their usefulness due to incorrect storage. Seeds need to be preserved and stored dry. As was previously mentioned, seed moisture content and storage temperature have the biggest effects on how long seeds last. The three main environmental elements that impact seed deterioration and loss of viability are moisture, temperature, and oxygen percentage. For over 90% of species, reducing seed moisture content (MC) to certain thresholds consistently lengthens the seed’s lifespan (Roberts 1973). These species are categorized as “orthodox” in terms of the conditions in which they should store seeds; under suitable dry, cool conditions, they typically maintain viability and germinability even after extended periods of storage. Ellis and Roberts’ improved viability equations have addressed the quantitative impacts of both drying and cooling for orthodox seeds. The life of the seed is often doubled for every 1% drop in seed moisture (when seed MC fluctuates between 5 and 14%) and every 5 oC drop in storage temperature (between 0 oC and 50 oC) (Harrington 1972). Low seed MC and low temperature are hence fundamentals of traditional seed storage. Careful regulation of these two factors is necessary to achieve optimal storage life. But most seed produced annually just has to be kept from harvest until the following planting season. Depending on the type of seed, it may or may not need to be stored at temperatures and relative humidity above room temperature. Regardless of any modifications made for unique uses, the local climate storage facility needs to have a few essential components (Barre, 1954; Wheeler and Hill, 1957).

Objectives of Seed Grading Minimization of heterogeneity to the lowest level and enhancement of the homogeneity to the highest level in the seed lots received by the processing unit. Principle Separation of seed lots based on differences in the physical properties of the seeds. Post harvest activities include threshing/ seed extraction, drying, pre-cleaning and conditioning, cleaning, fine-cleaning or grading, seed treatment, weighing and bagging/ packaging, sealing and labelling, storing, and transportation for marketing. Except for transportation and marketing, all these activities collectively known as seed processing. However, for most of the crop, threshing or seed extraction, basic cleaning even drying is done in the farm itself and in the processing unit, the threshed seed is received. The objective of the seed processing is to prepare the harvested seed in such a way that seed of highest purity and quality would be available for marketing, also for planting. The cleaning and the grading are the foremost activity of the seed processing. The seed, which is received in the processing unit, contains many undesirable particles, which as such cannot be used for marketing, hence cleaning and grading become necessary.

Objective of Seed Storage The primary goal of seed programs, which include storage, is to maintain the high standards of the seed from harvest until the crop is sown in the following or future seasons. Additionally, seeds are kept in storage for longer periods of time for a variety of reasons, including protection against crop failures during emergencies or natural disasters, maintaining active genetic stocks for breeding, germplasm preservation for long-term use, stock preservation for the domestic and international seed trade in response to market demands, and parental line seed preservation for the transnational seed industry during one or more growing seasons. The seeds of most major agricultural species can be classified as either orthodox or desiccation tolerant. A drop in storage temperature and relative humidity, commonly referred to as seed moisture content, shortens their shelf life. Seeds deteriorate even in dry storage because of alterations caused by pests and pathogens as well as physiological deterioration. This is accurate, even though the amount of time seeds takes to germinate and stay viable varies according to the makeup of the different plant species. A good seed program handles the seed with care, regulates the store’s temperature and relative humidity (or seed moisture in the case of hermetically sealed containers), and adheres to good sanitation practices to preserve the high planting value of the seed in terms of purity, germination, vigour, and seed health.

Concept: It’s a natural process that modifies the cytology, physiology, biochemistry, and physical characteristics of seeds. These modifications lower viability and ultimately result in the seed’s death. A decline in the proportion of germination indicates degradation, and weak seedlings are produced by seeds that do germinate. The factors that impact the ability of seed to be stored include the seed’s quality at the time of storage, its pre-storage history (environmental factors during pre- and post-harvest stages), its moisture content or ambient relative humidity, the temperature of the storage environment, the amount of time the seed is stored, and biotic agents. Seed will inevitably get damaged when being stored (Balesevic-Tubic et al., 2005). The quality of the seed at the time of storage, its pre-storage history (environmental factors during pre and post-harvest stages), its moisture content or ambient relative humidity, the temperature of the storage environment, the length of time the seed is stored, and biotic agents are factors that affect the seed’s ability to be stored. Different physical changes can happen to seed during storage because of factors like temperature, moisture content, and length of storage. The viability and vigor of the seeds may be impacted by these modifications.

Concept: Reduction of seed moisture content to the acceptable levels for enhancement of storability and longevity is known as seed drying. The moisture content of seed is negatively related to its storability. As the moisture content of seed increases, its storability decreases. Adequate drying of seed prolongs viability for reasonably long periods without cold storage. The process of drying begins with physiological maturity till storage/packaging of seeds to avoid deterioration. The seed is hygroscopic in nature therefore it adjusts its moisture content in equilibrium to the existing environment. Seed Drying Seed drying is the process in which an environment with low humidity is created to remove moisture from the seed up to the desired level without any damage to its viability and physical appearance. This seed is stored at low moisture content under the low relative humidity to enhance its longevity. The initiation of seed moisture content and the desired level are what dictate the amount of the drying process, and these elements are determined by the following • Type of seed: This will consider the longevity behaviour, seed content, and seed structure (i.e., how well the species stores energy).

Concept of Delinting Cotton seed clumps because of linters getting trapped on them after ginning. Gin-run seeds have very low flowability and do not singulate, making cleaning, upgrading, and precise metering in planting operations challenging or impossible. To singulate the seed and increase flowability, a variety of techniques have been and are employed. Most of the techniques entail removing the tags and linters entirely or partially, although other coating techniques have also been attempted with mixed results, both financially and technically (Mezynski, 1966; Webber and Boykin, 1907). Methods of Delinting 1. Mechanical Delinting Mechanical delinting is the usual technique used to improve the flowability of cotton seed. As previously indicated, mechanical delinting basically involves resharpening with finer, closer-spaced saws to remove part of the commercially valuable linters.

During processing seeds are cleaned, dried, and graded which are then treated with specific fungicide and insecticide. Seed at this stage is at best quality, which are then packaged into various packaging materials in a specific weight. Packaging or bagging of processed and treated seed is a requisite for easy handling of the bulk seed. Seed packaging can be defined as filling with seed, weighing and sealing the container whereas seed package as storage container where the seeds are kept for marketing or shipping or till the next sowing time. The Packaging of Seed Involves 1. Filling bags/ containers of uniform size with seeds of known weight. 2. Providing leaflets inside the package with information about any specific cultural practices needed. 3. Attaching labels or certification tags having information regarding all the quality parameters. 4. Temper-proof sealing of the bag. 5. Storage or transportation of the bags.

Objective Vegetable seed separation requires specialized training. A little carelessness during the seed extraction process can seriously harm the plant’s viability and vigor in addition to its outward look. Inadequate extraction methods can also result in in-situ germination. The seed can be separated by the following methods. 1. Manual Method (a) Maceration e.g., watermelon, (b) Crushing e.g., brinjal, (c) Scraping e.g., cucumber (d) Separated e.g., muskmelon, (e) Scooping e.g., pumpkins and (f) Extraction e.g., squashes.

Concept: Seed blending is the process of merging two or more types of the same species, for as Kentucky bluegrass cultivars Merion, Baron, and Park. Contrarily, seed mixing refers to the blending of two or more species, however every species may have more than one variation represented, such as Jamestown and Cascade chewing fescue combined with Merion and Fylking Kentucky bluegrass. Seed is typically distributed in blends, primarily Kentucky bluegrass blends, for sod growing purposes. For home lawns, parks, and other utility areas where upkeep levels would not be adequate to maintain pure Kentucky bluegrass turf, mixes of different grasses are typically employed. Naturally, when it comes to pure seed quality, no blend of grass seeds is superior to the individual ingredients. Every time a new blend needs to be made; extreme caution must be taken to ensure that the mixing equipment can be completely cleaned to prevent any contamination from unwanted species—bent grasses are perhaps the most challenging to deal with.

Pre-Treatment Before Sowing The natural conditions necessary for seeds to germinate are increased by pre sowing seed treatment. Many plants and trees’ seeds require a specific amount of time to mature in their immature portions and to overcome dormancy, which is the absence of certain elements that impede germination, so that the seeds can sprout. Depending on the type of seed, different environmental factors promote different levels of germination. For example, some seeds need to be kept in a very damp, cold environment, while others need to be kept in a dry, hot environment. Different techniques are employed to support seed survival and speed up germination, depending on the size of the lot, the species, the local conditions, and the availability of pertinent tools and facilities. Many species’ seeds don’t germinate successfully unless they are exposed to specific circumstances. Dormancy is the state in which seeds do not germinate unless certain circumstances are met. Conditions in the natural world could include being near fire or being eaten by animals.

Concept: A few of the numerous environmental elements that affect seed quality maintenance are moisture, temperature, humidity, and storage conditions. When some seedborne diseases or pests like insects are taken into consideration, seed quality can still be negatively impacted. Applying one or more pesticides to seed is the most economical and efficient way to keep pests away and improve seed quality. Because pesticides are harmful, handling treated seeds after application requires additional caution and safety measures. Definition of Treated Seed The definition of “treated” is “application of a pesticide or subject seed to a process intended to reduce, control, or repel insects, disease organisms, or other pests which attack the seed or seedlings.”

Stored grain pests are one of the major constraints in obtaining quality seeds. They cause substantial yield loss in storage conditions affecting both the quality and quantity of the produce. Apart from causing direct loss to the grains, they also make them unfit for consumption through their excreta, scales and wings resulting in development of unpleasant odour (Upadhyay and Ahmad, 2011). They also act as a source of medium for growth of fungi or bacteria (Daglish et al., 2018). The method of infestation of stored gain pests is different from the insect pests infesting crops under field condition. Generally, the infestation of storage pests starts after harvesting. It has been reported that in India, there is a loss of about 14 million tons worth Rs. 7000 crores due to the infestation by different storage pests (Chaubey, 2022). The post-harvest loss in terms of quantity and quality by different storage insect-pests accounts for about 10-30 per cent (Rajasri and Kavitha, 2015; Yaseen et al., 2019).

Sanitation Sanitation and maintaining good hygiene conditions are the important aspect of seed storage in storage godowns. Maintenance of good hygiene conditions will maintain the quality of produce in the long run (Mahapatra et al., 2014) and these practices should not be overlooked. The threshing floors should be cleaned properly before the operation so that there is no mixing of seeds or any insect-pests or pathogens. Harvesting and threshing should be followed by cleanliness of godowns to protect the seeds from the harmful pest and pathogens (Upadhyay and Ahmad, 2011). The storage godowns should be well lighted and the area should be preferably sunny, free from weeds and mostly situated at elevated areas. Damp areas should not be selected for building storage godowns as it will affect the moisture per cent of seeds thereby enabling easy growth of insect-pests and diseases (Parimala et al., 2013). Before bringing the new produce to the storage godowns, they should be cleaned properly. The cracks and crevices of storage godowns if any should be sealed ahead and the walls of the godowns should be whitewashed (Hazam and Kumar, 2022). The new seed lots should not be mixed with the older lots. The floors should be disinfected, and it should be cleaned regularly.

A Appendages - 1, 2, 15 Aerodynamic properties- 4, 35 Air screen cleaner cum grader -4, 35, 36 Alfalfa -4, 11, 15, 38 Air streams -4, 8 Aerodynamic properties -4, 35 Air cushion -8 Air stream -3, 7, 8, 35 Atmospheric pressure -8 Activated alumina -28 Awns -2, 14, 35 Active genetic stocks -45 Abiotic stressors -47 Active respiration – 49 Anoxia – 51 Aeration -29, 52, 85, 152 Antifreeze -55 Abscisic acid -55, 73 Accession number -56 Aerosols -61