ENCLOSURE TO PART III.
Serere Experimental Station, Uganda.
Aus.
At the present time breeding and selection is being done with the
following aims: —
Improvement of yield.
Purity of strain.
Maintenance of a regular 1 3-16in. staple.
Maintenance of quality.
Resistance to Blackarm disease.
SELECTION.
Single plants are selected from the growing crop in native plots
and from progeny rows of the previous year. From these plants
progeny rows are grown and 15 plants in each row very carefully
observed, the following records being taken :—
Daily flowering records.
5 day boll records.
Weekly growth measurements.
All plants are self fertilised by the tying method.
Every boll is picked separately and the following characters are
recorded for each boll: —
Loculus number.
Seeds from loculus.
Weight of lint.
Weight of seeds.
Lint length.
For each plant Lint Index and Ginning outturn are worked out.
As a result of the analysis of the above observations the most
promising rows are selected for growing in 1 acre increase plots in
which 100 plants are selected at random for boll records and these are
taken as the mean of the plot. Lint from these plots is sent home
for spinning tests and if the report is favourable the best strain is
grown in a large increase plot and also grown in a yield trial with types
in general cultivation. If results are satisfactory yield trials are held
at various sub-stations and then the strain is grown on in bulk and
eventually distributed to natives.
Cross BREEDING.
Although the difficulty in dealing with large F3 and F4 generations
is realised, a few crosses are being followed up.
Apart from selection work, the question of yield improvement is
being tackled by means of field experiments. such as sowing date,
spacing and method of culture.
In the case of newly introduced varieties, progeny rows are grown
for several years and similar records to those mentioned above are
made.
Complete meteorological data is obtained and used for correlating
with observations on progeny rows.
(Sgd.) G. W. Nye.
August, 1926.
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