Abstract: Planting date affects different growth stages as one of the
important factors in determining maximum cultivar Delaying planting date and
unfavorable environmental conditions have a negative effect on soybean growth,
development and yield. Four separate experiments were carried out in each season
at the experimental farm of Sakha Research Station, Kafr El-Sheikh during 2010
and 2011 summer seasons to evaluate seed quality and growth of six soybeans
genotypes i.e. Giza 21, Giza 22, Giza 111, H2L12, H30
and H32 under different planting dates i.e., 20th April, 5th
May, of 20th May and 5th June. Planting on 5th
May recorded highest values in all studied characters, except highest values
of crop growth rate and net assimilation rate was obtained from planting on
5th June. Giza 21 cultivar was consistently produced higher 100-seed
weight, seed yield (t ha-1), protein and oil yields (kg ha-1)
than those of other genotypes. H30 line had a consistently higher rate of vegetative
abscission and a generally lower 100-seed weight, seed, protein and oil yields
(kg ha-1) than other genotypes. Delaying planting until 5th
June altered vegetative stage significantly increase with the line H30 of crop
growth rate and net assimilation rate and the same line H30 gave the high rate
of relative growth rate and leaf area index on 5th May. Planting
in the first May is an effective management strategy to increase soybean yield
in Egypt.
