Vol. VII. No. 170. 



THE AGRICULTURAL NEWS. 



3.51 



SEED SELECTION AND THE BREED- 

 ING OF PLANTS. 



The above subject is discussed at considerable 

 length and in an interesting manner in an article by 

 Mr. A, D. Shamel, which appears in 'the Yearbook for 

 1907 of the United States Department of Agriculture. 

 The question of the improvement of agrit-ultural crops 

 by seed selection and breeding is one of great impor- 

 tance to all concerned, for it usually costs no more to 

 grow improved varieties of crops than unimproved 

 kinds, while the increase in production which results 

 from the use of superior seed gives an additional profit. 

 During the past ten or fifteen years this subject has 

 attracted a good deal of attention. 



As jioiiited out in the ai'ticle under consideration, 

 a primary reason for interest in the possibilities of this line 

 of work lies in the fact that where the same varieties of crops 

 have been grown year after year on the land of a given dis- 

 trict, and no seed selection practised, or efibrt.s at judicious 

 breeding made, these varieties tend to deteriorate and lieconie 

 unprofitable. Fungus and in.sect enemies also frequently 

 develop under these conditions, and these help to bring about 

 a still further reduction of the conniiercial' returns. This, it 

 may be pointed out, has alreadj' been experienced with the 

 Sea Island cotton crop in the West Indies, and the seed selec- 

 tion work constantly advocated aiid practised by the otticers 

 of the Imperial Departmeut of Agriculture form.s the chief 

 means at the plantei'.s disposal for keeping up and increasing 

 his crop returns, as well as of producing 'a strain of plants 

 which shiill be, to a huge extent, immune to insect and 

 fungoid attacks. 



The following e.^tracts from the article referred to 

 relate to possible improveuients that may be made 

 with maize and cotton l)y see<l selection work. To 

 obtain success, however, such work must be long- 

 continued and carried out with skill. The type of 

 t)lant required must be chosen, and seed sclect.ion 

 constantly practised with the object of fi.xing this 

 type : — 



The most important field for the breeder's work is in the 

 improvement of the established varieties of ciops by the 

 production of strains approximating more uniforndy to the 

 be.st types of these varieties. This lack of uniforndfy in 

 high productive capacity is responsible in great measure for 

 the present low average yield of nio.st of our croj)s in the 

 United States. It is due to the variability of the i)lants of 

 these varieties, which is more evident in the cross-fertili/ed 

 crops than in the self-fertilized ones. 1\\ the case of corn 

 this variability of jilants is particularly striking. It is the 

 experience of most corn breeders that it is not possible to 

 produce on an acre more than .5 bushels of uniform ears even 

 of our most improved straiiis. A large majority of the plants 

 produce ears of small size, irregular shape, and light weight. 

 Many of the stalks are barren. Only a small proportion of 

 the plants produce the maxinnun size and weight of ear. in 

 the cornfields of the central .Mississippi Valley the corn is 

 usually planted in hills, .3 feet 6 inches apart in the row. 

 The rows are arranged 3 feet 6 inches apart, and the hills 

 checked so as to permit cross cultivation. -.This arrangement 

 provides for 3,.").")G hills to the acre. .Vn average of about 3 

 kernels is planted in every hill. If every kernel produced 

 a uniform plant and the plants bore uniform ears weighing 

 1 Bb. each, the yield per acre would be about 10,068 lb., or 



about 1-55 bushels of shelled corn per acre. The fact that 

 the average yield of this section is less than 40 bushels per 

 acre is striking evidence that only a small proportion of the 

 plants bear ear.s of the maximum weight. 



A great deal of this variability and lack of uniformity of 

 the corn plants can be overcome by systematic selection of the 

 best seed ears year after year, and the propagation of this seed 

 alone, so that there is no danger of crossing with the undesir- 

 able types of plants or inferior varieties of corn. This fact 

 has been fully proved in the production (jf varieties Ijy many 

 years of continued selection of the seed which has 

 been found to be more productive and [irofitable for 

 cidture than the unselected or unimpmved sorts. The 

 gradual increase in yield of corn in Illinoi.s, Iowa, and other 

 great corn-growing States during the past ten years can 

 safely be attributed in no small degree to the use of the 

 im[)roved varieties produced in these sections by l)reeders. 



The cotton crop of the United States, which approxi- 

 mates to 12,000,000 bales is produced on about 30,000,000 

 acres. The average yiehl, therefore, is less than h bale 

 per acre. This low average yield is due in part to the fact 

 that a majority of the plants of the varieties now grown d<i not 

 produce a yield equal to that of the l)est plants in the fields. 

 The variability of the cotton |>lants in respect to the amount 

 of cotton borne by the individual [)lants is almost as marked 

 as the variability of the corn plants. Not oidy is there great 

 variability as respects the yield of cotton from individual 

 plants, but there is a corresponding variation in the character 

 of the lint borne by the different plants. It is the oi)inion of 

 many of the most successful growers that if the cotton varie- 

 ties now grown were improved .so that the plants conformed 

 more closely to the standards of the best plants in the fields, 

 the yield of cotton from these varieties would be doubled 

 without much additional expense in the cost of production. 



I 



CACAO SHIPMENTS FROM TRINIDAD. 



Particulars as to the ipumtity of cacao exported 

 from Trinidad, in September last, and the countries to 

 which it was shipped appear in the latest number of 

 the Proceed ingfi of the Agricultural Society of the 

 colony. 



The total quantity exported during the month was 

 708,013 lb., which brings up the shipments already made 

 since .January 1 last, to 3.5,471,11.5 lb. This refers oidy to 

 cacao which is the produce of the island. The quantity of 

 Trinidad cacao exported in the nine months ending Sei)tem- 

 ber 30, 1907, was 31,308,624 It... 



In the list of countries to which the cacao .shipments of 

 the past month were consigned, the United States comes 

 first, that country having taken 304,751 lb : France imported 

 271,811 lb. of Trinidad cacao in September, and takes second 

 place, whde Germany comes third with .59,200 Iti., and the 

 United Kingdom fourth, with 23,4-51 lb. London (|Uotatioiis 

 for Triniilad cacao varied from 64*'. on September 1 to 60.v. 

 on September 30. 



A tabular statement also shows particulars of the exports 

 of Trinidad cacao each year since 1904. In that year the 

 shijiments were nearly -50^ million (lounds ; in 190.5 they 

 <lropped to 48.\ million pounds; and in 1906 there was 

 a much greater fall, the shiiiments being little more than 

 28.1 million pounds. Last year they reached over 41 million 

 pounds, and there is every promise of that figure being 

 exceeded by the ex|)orts of 1908. 



