Studies on Seed Dormancy and their Alleviation Strategies in Finger Millet (Eleusine coracana L.)

The present laboratory investigation was carried out to study the duration, mechanism of seed dormancy and evaluation of different physicochemical alleviation strategies for seed dormancy in various finger millet varieties. Based on the study varieties were classified into weak, moderate, strong and very strong dormancy. The dormancy duration of the genotypes ranged from 21-35 days. Among the finger millet varieties, the highest dormancy duration of 35 days was observed Dapoli-1 and slight dormancy was noticed in Dapoli Safed-1 (21 days). Seeds without seed coat showed more germination compared to with seed coat. The percentage germination of seeds with seed coat was not higher than 40 per cent in finger millet genotypes while without the seed-coat exhibited more than 75 per cent of germination, indicating that the dormancy is imposed by the seed coat factors. Also, ABA in these varieties were estimated which varied from 3.283 to 3.344 picomoles per gram fresh weight of seed finger millet varieties. Amongst studied varieties, Dapoli-3 and Dapoli Safed-1 were found best responsive to the dormancy breaking treatments for most of the morpho-physio-biochemical seed parameters. The physico-chemical treatments, salicylic acid @ 100 ppm followed by KCL @ 1.0%, GA3 @ 200 ppm, KNO3 @ 0.5% and ethrel @ 50 ppm were most effective for finger millet varieties in release of seed dormancy and to improve the germination above Indian Minimum Seed Certification Standards (75%). Among all, one variety categorized under morphological seed dormancy and three in morpho-physiological seed dormancy based on percentage of seed germination before and after the seed dormancy breaking treatments. Above all, the findings can also be well utilized for crop improvement programme to transfer the dormancy character to the non-dormant genotypes to avoid precocious germination on the mother plant.