175 



Scientific Agriculture. 



(6.) By Cross-Fertilisation or Hybridisation. 

 Our greatest hopes in plant development are focussed on this method. An 

 ordinary planter could not be expected to carry it out, so little space will be devoted 

 to it. Just as breeders of live-stock will cross a Shorthorn bull with a native 

 cow, so plant breeders develop hybrids from two different plants. In this way 

 they hope to combine and fix the best qualities of both plants in a single specimen. 

 In every part of the world much wjrk is being done on this method of plant 

 improvement as its possibilities are so great. Even the good properties of some 

 weeds are being utilised, and it needs little imagination to picture what might be 

 accomplished by systematic and judicious plant breeding. In America crosses are 

 being tried between Sea Island and the Upland cottons, and also with the Egyptian 

 varieties, whilst in India the native varieties of cotton are being crossed with the 

 better exotic varieties. 



In Great Britain a wonderful work has been done on this subject with 

 grasses and cereal crops. It has been thought advisable to include an abstract 

 of an article which gave full details of the methods adopted by the best growers 

 of Sea Island Cotton. This description was from the able pen of Professor Herbert 

 J. Webber, the Physiologist in charge of the Laboratory of Plant Breeding, U.S.A. 

 Department of Agriculture, and the summary printed below is taken from the 

 Khedivial Agricultural Society's Journal, and was written by George P. Foaden, Esq., 

 Secretary of the Society. 



" In the selection of seed for cotton we have two primary objects in 

 view, viz., to obtain the greatest yield and the best quality. To select for both 

 objects at the same time is quite possible, though we think that the main 

 object in view can be accomplished by growing in the first place the very best 

 seed obtainable, and then selecting seed from the heaviest yielding plants, provided 

 the quality of those plants is equal to the best standard of that variety. In the 

 system of selection adopted by Sea Island planters most distinctive results have 

 been obtained. For example, one grower's ideal has been to obtain heavy yields 

 with but a secondary regard for quality, and this has been quite successful, the 

 grower's cotton being known in the market as that from heavy yielding plants but 

 whose quality is not "extra." Another planter again has selected for quality 

 only, and though yield has been to a certain extent sacrificed, yet his cotton 

 is sold for a much higher price. Thus starting with the same seed, two different 

 ideals may be reached according to the wish of the particular grower. As a 

 rule, however, our primary object is to increase the yield, and while striving to 

 obtain this we have to see that we do not sacrifice quality and other desirable 

 characteristics, but keep them at least up to the best standard. An area of 

 the variety under consideration is planted with the best seed obtainable, and 

 should possess a good soil and be thoroughly cultivated and manured in order 

 to obtain a good development of the plants, and consequently ideal conditions 

 for making selections. Just before the first picking, when some of the lower 

 bolls are well open on all of the plants, the field should be gone over and every 

 plant examined with reference to the productiveness, number and size of bolls, 

 vigour and shape of plant, earliness, etc. 



It is desirable to mark more plants than are expected to be used, because, 

 in going over and comparing the plants the first time, it is ordinarily found 

 difficult to carry the characters desired in mind with sufficient accuracy to enable 

 a careful judgment to be made. Therefore some fifty of the plants should be 

 first marked and numbered, so that these can be more carefully examined a 

 second time and the number reduced possibly one-half or more. The permanent 

 numbers should be placed only on the plants which are finally selected. Before 



23 



