560 



The Journal of Heredity 



begins to die at certain spots in the field 

 where growth is weakest, and the 

 disease spreads in concentric circles 

 until there are bare spots of an acre or 

 more. Always, however, occasional 

 stools survive in these diseased areas, 

 and continued observation of this fact 

 led to the conclusion that some of these 

 stools represented ])lants which had 

 greater resistance to the disease than 

 the average. It is well known that 

 varieties differ very noticcabh' in their 

 resistence to the disease, and if partic- 

 ularly immune strains exist in the 

 widely planted Cristalina cane, which 

 is so satisfactory in Cuba from most 

 other points of view, the fact is of the 

 greatest importance. At one time this 

 I^roblem was taken up by the Cuban- 

 American Sugar Co., and many strains 

 were selected for trial. Unfortunately, 

 the work was dropped before any results 

 were obtained, but the question is one 

 which promises to yield most valuable 

 results when the necessary attention is 

 given it. 



While cane and tobacco^ naturally 

 occupy the most important places in 

 Cuban agricultural investigations, to 

 the plant breeder there is probably no 

 field of greater interest than the im- 

 provement of tropical fruits. Cuba 

 possesses unusually good opportunities 

 for this work, due to the wide variety of 

 fruits which are found in the island, and 

 the great abundance of several of them, 

 such as. for cxc'implc, the avocado- and 

 the mango 



The northerner coming to Cuba is apt 

 to scoff at many of the native fruits, 

 and to compare them unfavorably with 

 the temperate fruits to which he has 

 been accustomed. In doing so, he fails 

 to remember that most of the tropical 

 fruits — ])ractically all with the excei)tion 

 of the pincaiJi)le and the banana — are 

 nothing more than half-wild seedlings. 

 In the majority of cases, even an occa- 



sional superior variety which may 

 originate through seedling variation is 

 lost because of the fact that vegetative 

 ]jro]mgation has never been generally 

 understood or applied in the tropics. 

 It is no wonder, then, that many of the 

 tropical fruits, in their present state, 

 are of rather inferior quality. On the 

 contrary, it is doubtful if the wild 

 [prototypes of many of (jur cultivated 

 temperate fruits are so attractive or so 

 ]jalatable as many of these tropical 

 species which arc in the same state of 

 nature. 



SELECTIOX OF FRUITS 



The most obvious means of improving 

 most of the tropical fruits, and the 

 one which offers the most immediate 

 results, is selection. With the great 

 number of seedlings which are found in 

 Cuba, it is not difficult to find occasional 

 ones which are much superior to the 

 average and worthy of propagation. 

 We are just now getting to the point 

 where we can bud or graft most tropical 

 fruit trees, and hence the work of im- 

 provement is just being commenced. 

 It can scarcely be said that Cuba is 

 behind in this work, though more has 

 been done in Florida in regard to work- 

 ing out methods of propagation which 

 will permit choice seedlings of mangos, 

 avocados and other fruits to be per- 

 l^etuated. Efforts at hybridization have 

 been few or practically none, yet in 

 several respects this field, too. offers 

 remarkably good o]Jix)rtunitics. 



The tropics have long been in need of 

 a grape which would flourish and pro- 

 duce abundantly, the Malaga type 

 iVitis vinijera) as well as the North 

 American varieties having jjroved to be 

 poorly adapted to tropical conditions, 

 though the South Euro])ean grapes are 

 occasionally grown in Cuba and other 

 tropical countries with a certain degree 

 of success. There exists in Cuba, 



'A short j)ai)cr on selected strains of tobacco was ])ul)lishc<l by Dr. Ilcinricli Hasselbring as 

 the result of his work at the Estacion Experimental Agrcmomica. This is the only paper dealing 

 with plant breeding that has yet been issued by the station, whose work was largely suspended 

 for a numl)er of years, because of jjolitical conditions, and has only recently been resumed with 

 vigor. 



^ The avocado (Persea gratissima Ciaertner, a member of the laurel family) is known in tropical 

 America as aguacate, a name based on the Aztec name ahuacatl. .\vocado is a corruiition 

 of this name, which seems to have become firmly established in the United States. The term 

 "alligator pear" is also used in this country, but is" misleading and objectionable. 



