Articles
THE ROLE OF SEED SIZE AND THE CONTROLLED DETERIORATION TEST IN DETERMINING SEED QUALITY IN BRASSICAS
Article number
362_32
Pages
263 – 272
Language
Abstract
Seeds from sixteen lots (six cultivars) of cauliflower (Brassica oleracea var botrytis) and six lots (three cultivars) of Brussels sprouts (B. oleracea var gemmifera) that were to be used in modular transplant production had, with only two exceptions, high germinations above 70%. In contrast the Controlled Deterioration (CD) vigour test revealed large differences in vigour, with germination after CD rangeing from 45–97% in cauliflower and 51–94% in Brussels sprouts.
These vigour differences were reflected in the root lengths of cauliflower after 3d germination, shorter roots being produced by low vigour seeds.
Tests of cauliflower seed emergence in module trays using a high and low vigour lot from each of two cultivars resulted in good emergence (>90%) for the two high vigour lots whereas emergences of only 75% and 62% were recorded for the low vigour lots.
Division of seeds into four size grades (>2.00mm,2.00–1.75,1.75–1.50,1.50–1.20mm) revealed large differences in seed distribution even within cultivars.
Where vigour differences occurred within cauliflower varieties the low vigour lots were found to contain a large proportion of small seeds whereas the low vigour lots of Brussels sprouts included more large seeds.
The laboratory germinations of cauliflower seeds within the four size grades differed little whereas in Brussels sprouts the tendency for small seeds to have a lower germination was particularly marked for two lots.
In both species the seed vigour, revealed by the CD test, was lower for seeds in the two smallest categories and in Brussels sprouts the CD germination clearly decreased as seed size decreased.
The effect of a brief period of storage on seed quality was emphasised by the reduced vigour of eight out of sixteen lots of cauliflower after one months storage at ambient temperature (13–23° C) and moisture contents rangeing from 6.28–7.65%. The significance of these results is discussed in relation to the production of uniform seedlings in modules.
These vigour differences were reflected in the root lengths of cauliflower after 3d germination, shorter roots being produced by low vigour seeds.
Tests of cauliflower seed emergence in module trays using a high and low vigour lot from each of two cultivars resulted in good emergence (>90%) for the two high vigour lots whereas emergences of only 75% and 62% were recorded for the low vigour lots.
Division of seeds into four size grades (>2.00mm,2.00–1.75,1.75–1.50,1.50–1.20mm) revealed large differences in seed distribution even within cultivars.
Where vigour differences occurred within cauliflower varieties the low vigour lots were found to contain a large proportion of small seeds whereas the low vigour lots of Brussels sprouts included more large seeds.
The laboratory germinations of cauliflower seeds within the four size grades differed little whereas in Brussels sprouts the tendency for small seeds to have a lower germination was particularly marked for two lots.
In both species the seed vigour, revealed by the CD test, was lower for seeds in the two smallest categories and in Brussels sprouts the CD germination clearly decreased as seed size decreased.
The effect of a brief period of storage on seed quality was emphasised by the reduced vigour of eight out of sixteen lots of cauliflower after one months storage at ambient temperature (13–23° C) and moisture contents rangeing from 6.28–7.65%. The significance of these results is discussed in relation to the production of uniform seedlings in modules.
Authors
Alison A. Powell, S. Matthews
Keywords
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