| The period of vegetative phase differed in different varieties. This
was manifested in variety C. 281 in which the flowering took place after
64 days while in varieties R.S. 31-1, N.P. 718 and Sonora-64, the flowering
took place 68 days from the date of sowing. The ears emerged in variety
S. 227 after 77 days, while the varieties C. 591 and Lerma Rojo flowered
after 80 days from the date of sowing. The period taken later for reproduction
leading to maturity was approximately the same in all the varieties. SPRAGUE
(1936) collected corn seeds after 10 and 25 days from pollination and dried
for 12 days at room temperature after which the germination was recorded
50% and 90% respectively. ROBERTSON and CURTIS (1967) collected winter wheat
seeds after 18, 21, 27, 30 and 36 days from anthesis and air dried them.
The germination were found 38%. 56%, 60%, 59% and 78% respectively. To permit direct comparison between early and fully matured harvest effects the per centage-reduction in germination was calculated by the Abbot formula [(x-y)/x] x 100, where x represents the percentage emergence of fully matured seed, y represents the percentage emergence of immature seed. According to seed testing rules as prescribed by I.S.T.A. recommendations the minimum germination percentage approved is fixed at 85% in case of wheat crop. While this germination percentage was recorded in above mentioned varieties harvested at 27% moisture. This moisture percentage was found in wheat varieties under reference on 37 days after flowering except variety Sonora-64 where this percentage of moisture is attained on 44th days after flowering (Table 1). Thus the wheat varieties which are conventionally harvested at full ripe on or after 59 days of flowering may be harvested even earlier without any detriment to the standard germination capacity of the seed. This finding is useful especially in view of the determination of a correct stage of harvesting. Thus saving the growers from the anxiety of waiting for a long time till they become quite sure of the desirable stage of the crop for the purpose of its harvesting. This also suggests that if in the event of a bad weather a variety can be harvested and it so with what consequences. Literature CROCKER, W. and L.V. BARTON 1957. Factors effecting germination Chapter VII. in "physiology of Seeds" KANTOR, D.J. and O.J. WEBSTER 1967. Effect of freezing and mechanical injury on viability of Sorghum seed. Crop Sci. 7 : 3. ROBERTSON, I.D. and B.C. CURTIS 1967. Germination of immature kernels of winter crop. Crop Sci. Vol. 7 : 3. (Received April 2, 1969) |
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