r59 



that all our seed may have resulted from cross-pollination." 

 7 — J. B. Thompson, Agronomist in Charge, Agricultural Experi- 

 "^ ment Station, St. Croix. 



(2) In the Report of the Virgin Islands Agricultural Experi- 

 ment Station for 1922 by J. B. Thompson, it is stated that many 

 plants in plots of Black Rock, Big Wig, and Key West yam 

 varieties of sweet potato produced during 1921 "seed balls" 

 which were collected and planted. " Unscarified seed was found 

 to germinate very irregularly." It is reported that there was 

 "a wide range of variation in leaf design, color and development 

 of vine in the plants within the same family." A total of 283 

 seedlings were grown. 



Porto Rico. "Unfortunately there is very little information 

 that we can give you relative to seed production in sweet 

 potatoes. The profuse flowering tendency of some varieties, 

 here in Porto Rico, has attracted my attention both at this 

 Station and at the Experiment Station in Mayaguez. However, 

 I have observed practically nothing in reg'ard to the setting of 

 seed by these blooms. 



"In a recent letter, Mr. T. B. McClelland, Horticulturist of 

 the U. S. Experiment Station, Mayaguez, states, that aside 

 from his knowledge that many of the best varieties of sweet 

 potatoes originated as seedlings, he has nothing further to ad- 

 vance in discussion of seed production of the sweet potato." 

 ^ — J. P. Griffith, Plant Breeder assigned to the improvement of 

 ^ sweet potatoes. Insular Experiment Station. 



Cuba. "The sweet potato seeds freely here, in December, 

 and this year I obtained some thousand seedlings. The seeds 

 begin to sprout 24 hours after sowing. The seedlings are very 

 healthy and strong. It is the first time I have grown seedlings 

 of sweet potato." Written May 29, 1922, and later on June 15, 

 1922, the following: " In our sweet potato fields we got more seed 

 where natural cross-pollination was possible because of the vicin- 

 ^ ity of other varieties." — Mario Calvino, Estacion Exp. Agro- 

 nomica, Santiago de las Vegas, Cuba. 



Santo Domingo. To Dr. B. H. A. Groth of Monte Cristi, 

 Dominican Republic, the writer is indebted for seed of sweet 

 potato illustrated in the accompanying figure and for much 

 information regarding his observations on the flowering and 

 seeding of this plant. The following are extracts from his 

 letters. 



(i) "Sweet potatoes bloom at any season of the year, and 

 they set seed sparingly. The age of the plant at flowering time 

 depends largely on the age of the cutting. If the root was 

 planted, it will bloom at about 5-6 months, if vines are planted, 

 as is always done in farm practice, the older vines may bloom at 

 once, while others may delay for 4-6 months. I think all 



