| dc.description.abstract |
Density grading of hybrid rice seeds by specific gravity separator significantly improved the
seed quality in terms of higher recovery of good seeds, higher seed weight, lesser split husk
seeds and maximum germination and vigour. High and medium density seeds were better in
seed germination and vigour as compared to low density seeds. Obtaining high quality seeds
(high and medium density grades) through specific gravity separation could compensate loss
of seeds due to rejection of low density seeds. The results on standardization of sodium
chloride salt concentration for upgradation revealed significant variations in all the physical
and physiological attributes studied due to concentration of salt solution. Considering
various factors such as seed recovery, separation of split husk seeds, seed weight,
germination, vigour and lustre improvement, salt solution concentration of four per cent for
ADTRH 1 and five per cent for CORH 2 were found optimum for seed quality upgradation.
Comparison of density grading methods revealed that the physical and physiological seed
quality parameters of seeds could be significantly improved by both salt solution upgradation
and specific gravity separation methods. However, the effect of salt solution upgradation was
much pronounced in physical parameters as observed through more high density seeds and
lesser split husk seeds, whereas the effect of specific gravity separation was better expressed
in physiological quality as witnessed through higher germination and vigour index. Hence,
both the methods could be adopted for upgradation of hybrid rice seeds depending upon the
utility i.e., salt upgradation may be adopted as pre-sowing seed conditioning and specific
gravity separation as pre-storage seed conditioning. |
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