FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET


2.4.7      The effect of seed size on emergence

 

Snyder & Filban (1970) compared fruits graded 2.58 - 2.98 mm and 3.77 - 4.12 mm in diameter sown at different depths, 3.2 cm and 5.1 cm in sand.  The deeper and smaller seed reduced establishment.  The hypocotyls of the deeper sown seeds were heavier as increased impedance forced them to widen.

In the field, emergence was as shown:-

 

 

 

Depth    of

sowing

Seed size (mm)

3.2 cm

5.1 cm

2.58 - 2.98

37%

20.5%

3.77 - 4.12

51%

38%

 

 

Snyder and Filban (1970) recommended seed rates should be increased by 33 per cent when using small seed, and that small seed should always be sown at less than 2.5 cm.  When soil moisture is limiting, deep sowing of large seed should be used. Lindsay (1980 personal communication) showed that seed less than 2.75 mm is eliminated in processing and so only large seed is used in practice.       There is nevertheless still a size range as investigated by Scott, Harper, Wood & Jaggard (1974).  The effects of seed size on development and yield of sugar beet were studied. small (2.8 - 3.6 mm), Medium (4.0 - 4.4 mm) and Large (5.2 - 5.6 mm) seed were used.

 

Overall the embryo weight was about 20% of the "seed" and larger seeds had fewer empty cavities.  They confirmed that the large seed within a seed lot gave a higher percentage emergence and was more reliable.

After processing, larger seed still performed better.

Plants produced from larger seed had higher root: shoot ratios but at harvest plants from medium and large seed produced similar yields.  Possibly selecting for seed size also selected different genotypes.

 

 


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FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET

[Introduction & Contents]     [Chapter One]     [Chapter Two]     [Chapter Three]     [Chapter Four]     [Chapter Five]     [Chapter Six]     [Chapter Seven]

[2.4]     [2.4.1]     [2.4.2]     [2.4.3]     [2.4.4]     [2.4.5]     [2.4.6]     [2.4.7]     [2.4.8]