| dc.description.abstract | The effect of different sampling dates on dry
matter production grain yield and mineral distribution and
accumulation in two cowpea varieties, 'Katuli 107' and
'MM4' were studied in a deep sandy loam soil of Murinduko,
sub-station of Embu Agricultural Research Station.
Results from this study indicated that there
were varietal differences in dry matter production and
grain yield. Katuli maintained superiority in these two
parameters over 'MM4'. Grain yield in Katuli was
attributed to the. high number of pods per plant and higher
number of seeds per pod. High dry matter production in
'Katuli '107' was mainly attributed to the leaves which
accounted for over 60% of the total dry matter in most of
the sampling periods.
The concentration of N, P, K, Ca, Mg and S
showed significant changes in the various sampling times
in the two varieties. Except for P, the period of active
accumulation of these mineral nutrients occurred between
flowering and mid-pod fill (5-8 weeks after emergence).
Phosphorus active accumulation occurred between seedling
and flowering. 'Katuli 107' accumulated more of these
nutrients than 'MM4' except for sulphur.
The results also indicated that the leaves
accumulated the highest amount of the mineral nutrients.
At mid pod fill the leaves contained 60-70%, stems
contained 20-25% and roots contained 7-12% of the total
nutrient content in the plant in both varieties. This high
nutrient content in the leaves decreased for most
nutrients after mid pod fill. This decrease suggested a
mobilization phenomenon of nutrients from the leaves to
the developing seeds. The results also showed that cowpea
varieties which have ability to accumulate more nutrients
produce higher dry matter and grain yields. | en |
