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Seed storage life in tropical areas is shortened by high humidity and temperature and the general inaccessibility to dehumidifying and refrigeration systems, resulting in rapid decreases in seed viability in storage as well as a high incidence of fungal and insect infestations. The dry chain, based on rapid and deep drying of seeds after harvest followed by packaging in moisture-proof containers, has been proposed as an effective method to maintain seed quality during medium-term storage in humid climates, even without refrigeration. In addition, seed drying with zeolite drying beads can be more effective and economical than sun or heated-air drying under these warm, humid conditions. In this paper, we review recent published literature regarding the dry chain, considering different crop species, storage environments and seed traits. In addition, we provide new original data on the application of dry chain methods and their implementation at larger scales in South Asia, Latin America and Pacific Island Countries. The clear conclusion is that the combination of reusable drying beads and waterproof storage containers enables the implementation of the dry chain in tropical climates, enhancing seed viability and quality in storage of many crop species. The dry chain approach can therefore significantly enhance seed security for farmers in many tropical countries. Finally, we propose actions and strategies that could guide further scaling-up implementation of this technology. [ABSTRACT FROM AUTHOR]

Cumulative oxidation of cellular macromolecules during storage reduces seed longevity. This study was undertaken to unravel the physiological and biochemical changes in rice seeds that contribute to deterioration during storage. Rice seeds maintained at three different seed moisture contents (SMC; 10, 12 and 14%) were stored in airtight glass jars. Half of the jars were flushed with nitrogen gas to provide modified oxygen conditions, while the other half were sealed with natural air (21% O2). Seed quality in terms of germination and antioxidant defence mechanisms was monitored after 3 and 6 months of storage at 25°C. The results showed that seeds performed better when stored at low SMC (10 and 12%), whereas the deterioration process accelerated in seeds stored at higher SMC (14%). Coupling high SMC with the availability of oxygen in the storage environment produced a negative effect on seed quality and longevity. Results from the antioxidant analysis showed more activity in seeds stored with oxygen at high SMC (14%) compared to lower SMC stored in modified oxygen conditions. Therefore, it is recommended that storage with low moisture levels (12%) or below (10%) is the best to preserve rice seed quality. However, at higher moisture levels (14%), the availability of oxygen in storage is more harmful to seed lifespan and quality. [ABSTRACT FROM AUTHOR]

Crop establishment is the most important phenological stage in the life cycle of crop plants which is governed by the pre-sowing quality of seed. From harvesting to sowing, a broad range of factors including genomics and prevailing environmental conditions can have marked influence on the quality of seed. These factors solely or in combination can cause a huge financial loss. However, control of all these factors for improving seed quality is a difficult task for the farmers to accomplish, however, some of the factors could be controlled. To tackle the issue, physical properties of seed are modified by the exogenous application of certain physical, chemical or biological compounds directly to the surface of a natural seed coat. Application of coatings through seed coating improves germinates phases, advances phenological events, enhances physio-morphological attributes, yield and most importantly the restoration efficacy of seed. In addition, seed coating offers an attractive option as a tool for enhancing crop establishment by propelling the challenges faced to agricultural systems and restoration of degraded systems. This review summarizes comprehensive information on various seed coating technologies and their potential role for achieving a cost-effective ecosystem by increasing food security. [ABSTRACT FROM AUTHOR]

• Smallholder farmers in developing countries store their moringa seed in conventional porous bags which are deteriorated at high relative humidity. • High seed moisture is the main culprit of seed deterioration in the storage. • Maintenance of seed dryness during storage can increase the shelf life of seed. • Moringa seeds must be stored in hermetically sealed super bag at 8% SMC for preservation of seed quality. This study was carried out to estimate the optimum conditions for moringa seed to maintain its quality during storage. Appropriate moisture contents and suitable temperature at the time of storage and reliable packaging materials may help to lower thresholds of respiration and extend the seed longevity in storage. Seeds of moringa were stored at 8, 10 and 12% seed moisture contents (SMC) in hermetic (super) and traditional (cloth) bags for six months. Highest germination (70%) and vigor were found in hermetically sealed super bag at 8% SMC after storage. Highest electrical conductivity of seed leachates and melonaldehyde contents for seed stored at 10 and 12% SMC at 10 and 25 °C in cloth bags depicted maximum deterioration and lowest values for these traits were found in super bags at 8% SMC. Oil and protein contents of seed were comparatively higher at 8 and 10% SMC at 10 °C. Seed stored in hermetically sealed super bags retained higher oil and protein contents as compared to cloth bags. Ageing induced deterioration at high seed SMC and temperature was associated with membrane damages and lipid peroxidation in seed. In conclusion, it is recommended that moringa seeds must be stored in hermetically sealed super bag at 8% SMC for preservation of seed quality. Under humid environment, seed storage in cloth bag should not be practiced as it increases equilibrium seed moisture contents, which promotes seed deterioration. [ABSTRACT FROM AUTHOR]

• Textile, oil and animal feed industries facing the problem of low cotton production. • The unavailability of quality seed is prime hindrance of high production of cotton. • Moisture is a main culprit behind poor seed quality during harvesting and post-harvest handling. • Advancements in post-harvest seed handling by introducing dry chain through hermetic storage can preserve cottonseed quality. Uniform and vigorous stand establishment is one of the basic determinants for profitable cotton (Gossypium hirsutum L.) production to fulfill the requirement of cotton and oil industries. However, low quality seed has been a major contribution to crop stand failure. Considering the whole cotton production line, quality seed is the virtue of good harvesting and post-harvest handling practices. In cotton growing zones of developing countries, picking early in the morning during humid weather carries excessive moisture and is prone to physical quality loss during the ginning process. Furthermore, conventional drying and storage modules inept to drying cottonseed effectively and is insufficient to preserve seed from ambient relative humidity (RH) fluctuations and therefore, cottonseed lose vigour and viability during storage. Alternatively, cottonseed picked during hot and dry weather is dry enough to endure physical abrasion during ginning and also sustain physical quality deterioration during processing. Advancements in post-harvest seed handling by introducing dry chain through hermetic storage can preserve cottonseed quality. Consequently, after harvesting seed quality can be procured for subsequent planting following improved drying and storage modules that ascertain a milestone towards seed security. This review elucidates to identify risks to cottonseed quality at harvesting and post-harvesting stages and helps to adopt management strategies to cope these challenges. [ABSTRACT FROM AUTHOR]

The seed industry and farmers have challenges, which include the production of poor quality and non-certified tomato seed, which ultimately results in decreased crop production. The issue carefully demands pre-sowing treatments using exogenous chemical plant growth-promoting substances. Therefore, to mitigate the above-stated problem, a series of experiments were conducted to improve the quality of tomato seeds (two cultivars, i.e., "Sundar" and "Ahmar") and to enhance the stand establishment, vigor, physiological, and biochemical attributes under growth chamber and greenhouse conditions by using potassium nitrate (KNO3) as a seed priming agent. Seeds were imbibed in 0.25, 0.50, 0.75, 1.0, and 1.25 KNO3 (weight/volume) for 24 h and then dried before experiments. The results of growth chamber and greenhouse screening show that experimental units receiving tomato seeds primed with 0.75% KNO3 in both cultivars performed better as compared to other concentrations and nonprimed control. Significant increase in final emergence (%), mean emergence time, and physiological attributes were observed with 0.75% KNO3. Collectively, the improved performance of tomato due to seed priming with 0.75% KNO3 was linked with higher activities of total soluble sugars and phenolics under growth chamber and greenhouse screening. [ABSTRACT FROM AUTHOR]