PLANT BREEDING. 3 1 



recently decided to proceed no further with the investigation 

 of wheats that are less " strong " than Yeoman. 



At the same time, an effort is being made to produce a wheat 

 sufficiently stiff in the straw to prevent " lodging " during rough 

 weather. The tendency to lodge, which is unfortunately common 

 amongst cereal crops, not only reduces the yield per acre and 

 adds to the cost of harvesting, but prevents farmers from 

 endeavouring to produce maximum crops by the increased use 

 of fertilisers. The work at Cambridge has already gone far 

 enough to show that stiffness of straw can be brought under 

 control, and crosses that breed true have been obtained which 

 combine the high yield of " Yeoman " with a straw sufficiently 

 strong to resist any ordinary weather conditions. Stocks of 

 seed of the best of those varieties are now being worked up. 

 About half-an-acre has been sown with them during the past 

 autumn, and the seed secured from this area in 1922 will go 

 to the National Institute of Agricultural Botany, so that the 

 varieties may be tested out under farm conditions and a sufficient 

 quantity of seed obtained for distribution to farmers. 



The question of disease resistance is kept prominently in 

 view by the Institute. Resistance against the common yellow 

 rust was early found to be an inheritable quality, and practically 

 all the types now under investigation are more or less immune 

 from this disease. 



A promising breeding experiment is at present in progress 

 with the object of increasing the number of grains set per spikelet, 

 and thus, possibly, the yield of the crop. In English varieties of 

 wheat, although seven or eight flowers are produced on each 

 spikelet, as a rule only about four grains are developed. Some 

 years ago, however, a variety obtained from the Szechuan 

 district of China was found to have the peculiarity of setting 

 every flower that was produced, although in other respects 

 the variety was very inferior to any ordinary English wheat. 

 For several years efforts have been made to combine this flower- 

 setting quality with the many spikelets characteristic of English 

 types. Hybrids between the Chinese and English varieties 

 have been secured, and from these it is clear that the power of 

 setting grains may be inherited. Upwards of thirty distinct 

 hybrids, which breed true, are at present being tested on small 

 field plots. 



It has been thought desirable to give only a brief general 

 account of the wheat-breeding investigations, sufficient to 

 indicate the main lines on which work is proceeding. The 

 amount of detail involved is, however, very great. In 1921, 

 for example, the second generation of wheat crosses amounted 



