PLANT BREEDING IN CUBA 



Rich Opportunities for Geneticists — Attempts Made to Utilize Natural Resources- 

 Interesting Problems of the Mango and Other Fruits 



F. S. Earle, Herradiira, Cuba, and Wilson Popenoe, 

 Bureau oj Plant Industry, Washington, D. C. 



A DISCUSSION of plant breeding 

 in Cuba must necessarily deal 

 ^ more with opportunities than 

 with accomplishments, since it 

 is only in very recent years that an}' 

 attention has been devoted to this 

 subject, and the work is still in its 

 infancy. Along several of the most 

 imjjortant lines, however, a good start 

 has been made, and with the remarkably 

 rich field which Cuba possesses it is 

 scarcely conceivable that the near 

 future will not see some noteworthy 

 advances in the development of new 

 and superior forms of cane, tobacco, 

 maize, vegetables and tropical finiits. 

 Naturally enough, when the improve- 

 ment of Cuban cro])s was first taken 

 up eleven years ago, when the senior 

 author was called to the island to 

 organize the Government Experiment 

 Station, the most important cultures 

 were the first ones to receive attention. 

 The testing of seedling sugar canes has 

 been carried on for the past ten or 

 twelve years at the Harvard Exj^erimcnt 

 Station, which is maintained by Mr. 

 Atkins, president of the American 

 Sugar Refining Co., at his Soledad 

 plantation near Cienfuegos. As is well 

 known, sugar cane is usually propagated 

 by jjlanting the stalks; seedlings were 

 first successfully grown by the British 

 in Barbados and Demerara, but recentl\' 

 they have been jjrojxigated throughout 

 the trojiical world in great numlxTs, in 

 the hojK' of ()l)taining varieties which 

 would be more resistant to certain 

 diseases or contain a greater amount 

 of sugar. At Soledad the special jDrob- 

 lem has been to find varieties so well 

 adajjted to local conditions that the 

 yield can be maintained in the face of 

 lessened soil fertility due to long- 

 continued i)lanting to this one crop. 

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The soils of the Soledad district are 

 peculiar in not responding to the use of 

 commercial fertilizers. Other Cuban 

 soils, especially the red lands and the 

 sandy loams, give excellent results when 

 fertilizers are applied to them, and their 

 productiveness can be maintained with- 

 out difficulty. Since sugar cane occu- 

 pies the land continuoush' for a number 

 of years the soil cannot readily be 

 improved through crop rotation or 

 green cover crops. Stable manure is 

 out of the question, hence when com- 

 mercial fertilizers fail to give the desired 

 results the problem is a serious one. 

 What possible solution could be found 

 for such an unusual problem — to 

 make a plant continue to yield heavily 

 while the soil in which it grows is being 

 steadily exhausted ? Few investigators 

 would have thought of genetics as a 

 solution; but the attempt to get around 

 the situation through scientific plant 

 breeding was made and is proving success- 

 ful, since many of the seedlings are 

 giving satisfactory yields even on thin 

 and exhausted soils. 



DISEASE RESISTANCE 



In addition to the production of 

 seedling canes which will maintain a 

 profitable yield on poor soils, an effort 

 has been made, in a very limited way, 

 to obtain through selection strains 

 which will ]:)e resistant to the root rot, 

 a disease sui)i)osed to be caused by 

 Marasniius sacchari. On virgin timber 

 lands in Cuba cane will often continue 

 to give profitable results for twenty or 

 twenty-five years without rei)lanting. 

 At length, with soil exhaustion and the 

 increase of disease due to continuous 

 cultivation of this one croj), the fields 

 die out and must be rc])lanted every 

 lliird or fourth vear. The cane usually 



