PART 111. } 
A preliminary test will be made each season with part of the bulk 
seed from the progeny rows which appear to be particularly promising, 
using Sowering and fruiting studies to decide which strains are worthy 
of inclusion in full field trials in the foliowing season. The balance 
of the bulk seed being sown in each case in an increase plot. 
Full field trials will consist of plots, sown with seed obtained 
from the increase plots, arranged in such a way as to give a known 
degree of accuracy to the results obtained. All new strains used in 
these trials will be tested against the ordinary field crop as a whole as 
well as against one another. 
The most superior strain will be further bulked with a view to 
replacing with it the ordinary field crop as time goes on. The aim 
will be to retain the pure parent stock and from this obtain further 
supplies of seed wherewith to renew the general seed stocks as 
required. 
Any new varieties obtained in the future will be first sown in 
observation plots and then selections from them will be passed to the 
progeny rows for purification. 
II. UxioN oF SouTH AFRICA. 
Work and methods employed are on similar lines to those 
described above under ‘‘ Nyasavranp.”” There are two distinet 
climates involved, represented by the middle and low veldts. There 
are two plant breeding stations, at Rustenburg and Barberton, 
representative of the two climates. The main plant breeding problem 
at Rustenburg is the general improvement of existing types with a 
comparatively short season as a limiting factor. A preliminary issue 
of seed from plants selected by the Plant Breeder has been made this 
year. This will be followed by pure strains. This year’s results 
indicate suitability to local conditions and show marked improvement 
in quality. 
At Barberton, representing low veldt conditions, the main 
deciding factor appears at present to be Jassid, which, combined with 
boll worm, is threatening the industry in many areas. There seems 
to be every hope that a means has been found to combat this pest 
through jassid-resistant strains; multiplication of one of these is 
proceeding. 
III. SwaziLaND, 
* The Cotton specialist arrived in Swaziland in September, 1925, 
and has seen one complete cotton season. An area of some 20 acres 
at Bremersdorp was leased, and on this, in addition to the various 
series of experimental plots, fairly large areas of the five commonly 
grown varieties were planted, as well as a few small plots of 
introduced American varieties, all of which served as material from 
which selections were made. Some 130 plants were marked in the 
field, the characteristics to which the greatest importance was attached 
being resistance to the attack of jassid. This pest appeared rather 
late in the season, but its attack was considered sufficiently severe to 
afford a test of the resisting qualities of the selections. These are in 
process of elimination and at present some 40 are still retained. 
The programme for the coming season is to plant out progeny 
plots from the survivors, and for this a small area which is known 
not to have grown cotton for many years has been selected. Besides 
114