CROP-PLANTS 34 1 



RESEARCH ON CROP-PLANTS 



CEREALS 



A survey of the sorghums [Sorghum vidgare) was inaugurated by 

 the Economic Botanist at Kew Gardens, Mr. Sampson, in col- 

 laboration with the British colonial agricultural departments. 

 The material collected has been critically studied by Mr. J. D. 

 Snowden (1936). Mr. Burkill, on the basis of Snowden's work, 

 has written an historical study of this cereal (1937). The co- 

 operative study of this crop, which entailed a study on the spot 

 of the agricultural characters of different varieties, has perhaps 

 called attention to its importance, and several departments have 

 carried on the work of improvement, notably in Northern Rho- 

 desia, Nyasaland, Tanganyika, and Nigeria. The collection of 

 material at Kew has also made it possible for officers of agricul- 

 tural departments to make a special study of this crop when on 

 vacation. In the Union of South Africa selected varieties of sor- 

 ghum have shown marked resistance to 'witch weed' (Striga), a 

 root parasite which causes great losses to this crop as well as to 

 maize and certain other cereals. 



Material of a large number of bulrush millets [Pennisetum) has 

 been collected at Kew and has been critically examined and classi- 

 fied by Hubbard and Stapf. It has been shown that these millets 

 have been derived from more than one wild African species (Fl. 

 Trop. Africa, 1934). In Tanganyika bulrush millets have been 

 selected to produce compact heads, and quick-growing varieties 

 have been bred for dry areas. 



In Nigeria the selection of pure strains has been undertaken with 

 both grain sorghums and pennisetums at the agricultural station 

 of Samaru in the Northern Provinces. This has resulted in increased 

 yields up to 30 per cent, but results to date are somewhat erratic, 

 and yields of 30 per cent over the average in one season have some- 

 times been followed by yields of 5 or 10 per cent under average 

 in the following year. In general it can be concluded that strains 

 of sorghum can be selected which give improved yields in the area 

 where the selection is actually Carried out, but appear to be incap- 

 able of competing with local varieties elsewhere, even if only fifty 

 miles away. In the Gold Coast, where the Botanist devotes much 



