| dc.description.abstract | Two experiments were carried out between October and
December 1988, and repeated between January and May 1989 at the
Field Station, Faculty of Agriculture, Kabete \campus, University
of Nairobi, Kenya, to investigate the effect of four nitrogen rates
(0, 60, 80 and 100 kg N ha") on cowpea leaf yield, dry matter,
nutrient composition, nitrate accumulation and root nodulation
using two varieties ( Vita-3 and K-80 ). Leaves from Vita-3 were
also used for in storage experiments in which water and ascorbic
acid changes were determined at room (21±7°C) and refrigeration
(4±1°C ) temperatures.
Results showed that application of N had no
significant effect on fresh leaf yield, leaf dry matter, crude
fibre, beta carotene, ascorbic acid, minerals and nitrate
accumulation. The two varieties too, did not show significant
differences in leaf nutrient composition.
Nitrogen application reduced root nodule weight per
plant significantly but had no effect on nodule numbers per plant.
Both varieties differed significantly in nodule numbers and
weights per plant.
Leaf protein tended to increase with increased N-rates
and was significant in one experiment in which it was 28.6% for
cowpea that had received 100 kg N ha-'. Both leaf ether extract and
ash increased significantly with applied N. A few minerals such as
K+ and ca " tended to increase with applied nitrogen though not
significantly.
Laboratory experiments showed that cowpea leaves lost
fresh weight, significantly at room and refrigeration storage.
Losses were,however,less drastic in refrigerated storage relative
to room storage. Significant losses in ascorbic acid occured for
cowpea leaves stored for three days at room temperature. When
refrigerated, the vitamin, however,was not significantly altered | en |
