Abstract:
The objective of this study was to determine the effect of the environment on
the quality and yield of seed from different seed lots. Localities with different
soil types, soil structures and climates were chosen to grow seed lots of the
soybean (Glycine max L. Merril) variety Prima. After harvesting by hand, the
seed was analysed for oil, protein and mineral content. Physical quality,
germination and vigour tests were also done. There were big differences in
the growing conditions and precipitation. Rainfall varied from a high of
956mm for the Komatipoort locality to a low of 149mm for the Delmas
locality. The percentage defects varied from 0.5% for Delmas to 78% for
Komatipoort and the germination percentage from 94% for Klerksdorp to
16% for Komatipoort. Suitable temperatures and rainfall lead to the infection
ofthe disease Phomopsis longicol/a atthe Komatipoort locality. This was the
reason for poor germination results and high percentage defects in the seed.
Vryheid had the highest protein percentage of 38.53% and Delmas the
lowest of 33.34%
The harvested seed was planted at Greytown first on the Redgates and
Chaileyfarm in a randomized block design in orderto determine germination,
vigour and yield for seed from different seed lots multiplied in different soil
types and climatic conditions, and now planted under similar climatic
conditions. The analyses and comparisons in terms of leaf area index at the early flowering (R2) stage, plant height at harvest mature (R8) stage, pod
height at R8 stage and eventual yield, did not reveal any significant
differences (P=0.05). No significant differences were recorded for seed
yield Yield. The average yield of the Chailey locality however was
1021 .9 kg/ha higher than the average yield ofthe Redgates locality. Growth
conditions did dominate the effect of different seed lots. Poor germination
and stand also had very little effect on seed yield as demonstrated by the
Komatipoort treatment. Although plantpopulation was 150000 plants per
hectare lower than the average for both trials, final seed yield were not
significantly different (P=0.05) Therefore plant population had no influence
on the yield.
The author conclude thatfor soil types, soil structures and climatic conditions
typical of this study, no effect for seed lot on yield could be demonstrated
