----- Journal of Crop and Weed 3(1) : 19-30 (2007) Effect of different hydration-dehydration and dry-dressing treatments on viability of green gram (Vigna radiata wilczek L.) seeds P.K. BANDOPADHYAY, SANJOY SHIL, SUDIP DHAR & SWAMINATH GUPTA Department of Plant Physiology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741252, Nadia, West Bengal ABSTRACT Under West Bengal conditions, maintenance of vigour and viability of green gram seed (Vigna radiata Wilczek L) is a serious problem from harvest to next sowing. To over come this problem, experiments were conducted under ambient laboratory conditions to slow down the ageing process of the seeds during storage. High vigorous seeds of 2-3 months old were taken and subjected to Hydration dehydration (H-D), Moisture-equilibration & drying (ME  D) and dry  dressings with powdered plant materials of Ashwagandha root (200 mg kg -1 ), Zinger rhizome (100 mg kg -1 ), Turmeric rhizome (100 mg kg -1 ), Trigonella seeds (200 mg kg -1 ), jute leaf (100 mg kg -1 ) and pharmaceutical preparations of vit C (celin tablet) and salicylic acid (Disprin tablet) were done. Among the treatments plain H  D with water for 3 hours and slow imbibition for 48 hours with ME  D showed significantly good effect over untreated control in respect of germination percentage and seedling growth. The treatment effect were magnified under accelerated (40 0 C + 98 0 % R.H.) and natural ageing (27  5 0 C and 73  7% R.H.) conditions where as in dry dressing with powered plant materials had significant beneficial effect in maintaining seed vigour and viability over control. Among the treatments with powdered plant material such as Turmeric rhizome and jute leaf as well as pharmaceutical preparation vit C (celin tablet) had highly beneficial effect under accelerated and natural ageing conditions. Peroxidase enzyme assay study showed betterment effect in all the treatments indicating that free-radical formation due to ageing quenched by the treatments over control. Key words : Hydration-dehydration (H-D.), moisture-equilibration & drying (ME  D), dry dressing, accelerated ageing, natural ageing. Green gram (Vigna radiata Wilczek L.) seeds after harvest passes through the monsoon season and shows a significant fall in germinability by the time of next planting. According to Roberts (1972) the primary cause of loss of viability may be developed due to its extrinsic factors namely fungi, bacteria, nematodes, moisture, temperature and ionizing radiation and intrinsic or physiological, biochemical and molecular basis of ageing. To over come this problem, many seed treatments have been practiced mostly in two broad groups in most of the orthodox seed such as hydration- dehydration treatments with mild solution of inorganic salts and another with dry dressings with organic materials to slow down the ageing process at the time of storage or at mid-storage intervals showed very much effective results. The beneficial effect of hydration-dehydration treatments as well as with dry dressing helps to decrease/eliminate free-radical formation due to lipid peroxidation during ageing at storage, which damages the bio-membrane of a cell. Present study also emphasize that seed ageing is also related with aldehyde production and this seed treatment some how minimize the aldehyde production and check the damage of bio-membrane. MATERIALS AND METHODS Procurement of seeds Seeds of green gram [Vigna radiata wilczek (L.)] have been collected from Instructional Farm, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal. Seeds after collection were cleaned and well dried thoroughly to the moisture level of 9% and then stored in bottles with properly sealed mouth after testing the germination percentage of seeds. Seed variability test Seed viability test were conducted as per ISTA rules in the laboratory condition by keeping the treated along with control seeds in perforated paper packets in desiccator (8″ diameter) over water in such a way that, there would be no contact of paper packets containing seeds with water. Lid of the desiccator closed air tight and the whole setup kept in BOD at 40 0 C and 98 0 % RH over a period 8 days for ageing. Then the seeds were set for germination test in glass-plate method. Seedling growth Seedling growth were recorded under laboratory conditions (in glass plate method) after 144 hours of germination set up were done in 3 replications and their mean germination percentage were recorded. Statistical analysis Statistical analysis was done adopting the method of Analysis of variance by Fisher 1948. Randomized Block design was adopted for analysis of data. Hydration-dehydration treatment To find out the efficacy of hydration- dehydration treatment on green gram seeds, soaking duration was standardized in laboratory by soaking the seeds in beaker taking 20 gm of seeds in 40 cc of water following the method of Dasgupta and Basu (1975) with little modifications. Seed soaking was done for 1 to 6 hours duration under ambient condition and the seeds were dried back to its original moisture content by spreading the seed over bloting paper under sun at least for 4 days or till it reaches its moisture content to original level. After thorough drying, the seeds were stored in paper packets and kept in desiccator over CaCl 2 for a week for stabilization of seed moisture. pdf Machine - is a pdf writer that produces quality PDF files with ease! Get yours now ! “Thank you very much! I can use Acrobat Distiller or the Acrobat PDFWriter but I consider your product a lot easier to use and much preferable to Adobe's" A.Sarras - USA