= PART IL
Some account must be given in this paper of how the seed is to
oe improved; the other causes of low yields, except drought, will be
eilminated in the course of nature.
It has been stated that under ordinary favourable conditions
average yields of from 10-15 bags per acre could reasonably be
expected and ‘are obtained in the maize belts of this Colony. Were
the seed well bred there is little doubt that these yields could be
increased by 50 per cent. Planting at the usual rate and allowing
for a good proportion of misses there must usually be at least 8,000
plants to the acre. If each plant gave one cob with only lb. of seed
in it that would mean a yield of 20 bags to the acre. A half pound
cob is a comparatively small one and many of the cobs harvested from
the maize fields weigh a pound or more. = Why is there not even a
half pound cob on each plant? The answer is that the seed is poor,
a large proportion of the plants yielding very poor cobs. South
African maize varieties are being imported but they take some time
to acclimatise and are not necessarily suited to this country. There
is, however, a very mixed variety commonly in use throughout the
country and which appears, on the whole, to do very well. = This
variety is probably a cross between Hickory King and Hickory Horsetooth.
 The number of rows on the cobs varies from eight to 14.
Experience shows that cobs with ten to fourteen rows yield best;
indeed it might be said that a 12 row cob is the ideal at which to aim.
This Hickory Hybrid is acclimatised to the country and it is
likely that better results can be obtained by breeding and selection
within this hybrid than by importing foreign varieties. For the past
three years officers of the Department of Agriculture have supervised
this selection work on certain farms in the Nakuru area. The ordinary
method of selection in the field has been adopted; any farmer of
ordinary intelligence can do this work himself if he obeys the rules.
The reason why the work is being supervised by a Breeder is that an
attempt is being made to produce a new variety of flat white maize
for this Colony. Coordination of work is therefore essential as it is
important that plants and cobs should be selected every year which
tend more and more towards the accepted ideal type.
It is too early yet to give any exact results of this work of
selection, but a glance at the breeding plots in the Nakuru area will
show that much has already been achieved. On one farm the selected
seed has given a yield of five bags more per acre than the unselected
seed. The plants are more even and more vigorous, the cobs are
better placed, better covered and larger, and approximate more to
the ideal type. In comparison with the rest of the fields there is a
marked absence of those weak plants with poor cobs which both in
themselves and as parents do so much to lower the yield of maize in
this Colony.
From this work of selection alone it is likely that the average
yields of the Colony will show a marked increase in a few years’ time.
Maize does not suffer as seriously as other crops from pests and
diseases. The chief are cut worm and stalk-borer, ear-rot, and
‘‘ streak ’’ disease.  Ear-rot can be largely overcome by breeding
plants with well-covered cobs.
If such a disease as ‘‘ streak ’’ or rust became serious on maize
then the services of a Plant Breeder would have to be enlisted to try to
save the crop. Plants would have to be purified for resistance to these

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