dc.description.abstract | Two experiments were conducted between June 1988
and July 1989 at the Faculty of Agriculture Field
Station, Kabete Campus, University of Nairobi, to
study the influence. of nitrogen (N) application rates
(0, 5, 10 and 15 gN per plant) on yield quality and
storage
olpracea
ability of kale and collard (Brassica
var. aceDhala D.C.) leaves. Calcium
ammonium nitrate (CAN) was used as the N source.
Leaves were harvested at intervals of 10 days for a
period of upto 140 days after transplanting. Leaf
yield at each harvest was determined and leaf samples
stored on the shelf for 3 days and in a refrigetor
for 21 days.
Leaves were analysed for crude p,"otein, crude
fibre, crude lipid, total ash, calcium, ascorbic acid
and beta-carotene, after every other harvest. During
storage, ascorbic acid retention was determined
initially and at intervals of 2 days of storage for
shelf and 7, 14, 21 days of storage for
refrigeration_
Increasing N application significantly increased
leaf yield. Applying more than 109 of N per plant,
however, did not significantly increase yields.
yield actually decreased. The results showed
Leaf
that
leaf yield increased with plant age upto 60 days
after transplanting, then remained almost constant
upto 120 days after transplanting beyond which there
was a drop of about 65%. per consecutive harvest.
Application of N significantly increased crude
protein, crude lipid, total ash and Beta-carotene but
decreased ascorbic acid and crude fibre. Calcium
remained constant. Crude protein, ascorbic acid and
Beta-carotene significantly decreased whereas crude
fibre tended to increase with plant age. Crude lipid
tended to increase with plant age upto 60 days after
transplanting then significantly decreased for the
rest of the harvest period. Total ash and calcium
did not change significantly with plant age.
Ascorbic acid in stored leaves significantly
decreased with increasing storage time. Highest
decrease of about 72% being in leaves stored on the
shelf and lowest of about 25% in the
under refrigeration were observed.
leaves stored | en |