THE 



TROPICAL AGRICULTURIST 



AND 



MAGAZINE OF THE 



CEYLON AGRICULTURAL SOCIETY, 



Vol. XXVII. COLOMBO, SEPTEMBER 15th, 1906. No. 3. 



The Improvement of Local Varieties of Plants. 



A few erroneous notions seem to be abroad again, with regard to the keeping 

 up of the high standard of* local races of plants, and it may be well to correct them. 

 The Agricultural Society is importing many valuable kinds of seed, and people 

 are saving the seed from these, expecting to get an equally good result in the next 

 generation. They find they do not get this result, and they wonder why, or say it is 

 the "Ceylon climate," though it is the simple expression of a natural law, which 

 cannot be altered by all the agricultural societies in the world. The majority of 

 improved races are due to continual selection of the seed, and unless this selection 

 is carried out in every generation, or unless the Society buys good (i.e., selected) seed 

 for every generation, the result must be disappointment. Deterioration is in 

 general about three or four times as rapid as improvement, and supposing, for 

 instance, in cotton, beginning with a staple of 1 J inch, we have in a hundred gener- 

 ations improved this length to 2 inches, it will fall away in about ten generations or 

 less to 1 i inch again, unless selection be practised. [These numbers are, of course, 

 purely hypothetical.] 



Improvement of races is carried on in two ways, and we must carefully 

 distinguish between these. It may be by the continual selection of the better, in 

 the almost infinitesimal differences which always mark any crop or character, or it 

 may be by the picking out of absolutely new characters, which appear as what are 

 called sports at long intervals ; these do not go back to the race from which they 

 sprang, but may themselves be improved by selection, and the improved race 

 will go back again to their starting point if left alone. Thus, for instance, in the 

 carnation, a new pink variety suddenly appears as a single, or as a very few, 

 individuals, among a lot of red ones. This pink form may be cultivated, and its 

 offspring, if not crossed with the reds, will remain pink for any number of 

 generations. Mr. Lock, lately Scientific. Assistant at Peradeniya, has produced 

 an excellent race of "native" peas by crossing on scientific principles, that will 

 not " go back," and we are now busy multiplying these with a view to putting 

 them on the local market. 



Speaking generally, these sports only appear among the offspring of crosses, 

 i.e.. mainly among garden plants, and if we start to look for them in a field crop, 

 we may be grey-headed before one appears. The improved races in field crops, be 

 they of rice, potatoes, cotton, or what not, are practically always due to selection, 

 and we must either practice selection ourselves to keep up the quality, or buy 

 selected seed from elsewhere at considerable expense. Nothing in this world that 

 is worth having, can, as a rule, be got without considerable labour or expense. 



