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Sef.d of sweet potatoes in Queensland 

 In the earlier account published in this Journal and already 

 cited, a quotation was given from an unpublished report by C. B. 

 Brooks to the effect that in Queensland, Australia, "the sweet 

 potato apparently is not fertile to its own pollen and that to pro- 

 duce seed it is necessary to cross-pollinate by hand." Since this 

 was published a report has come to hand bearing the date 1923- 

 which contains the following interesting statement. 



"The seed was secured from those growing in the propagating 

 bed. Approximately six crops of vine cuttings were removed 

 during the summer, and it was in the subsequent growth that was 

 allowed to stand over the winter that blooms appeared. It was 

 found that although several sorts flowered very freely, no seed 

 was produced. It was thought that in all probability the flowers 

 might not be fertile to their own pollen, so recourse was made to 

 cross-fertilization. This produced fertile seed." 



Seed of sweet potatoes in the Virgin Islands 



The breeding of sweet potatoes from seed has been continued 

 at the Agricultural Experiment Station, St. Croix, Virgin Islands, 

 and concerning the results there obtained the Director of the Sta- 

 tion, Professor J. B. Thompson, has written as follows: 



"You will be interested to hear that we have done a little work 

 this year with the sweet potato, involving controlled pollination. 

 I have just now finished collecting the last seed to mature and am 

 sending you a summary of the results. You will note that we 

 used a relatively large number of combinations. This comes 

 from the fact that we regarded this year's work largely in the 

 nature of the preliminar}^ operations and we had only small ex- 

 perimental plantings to work upon and they did not flower in 

 quantities to suffice for doing all the work we wanted to do on 

 the varieties we preferred. 



"Your results seem to bear out the theory of self -incompati- 

 bility and our limited work on this line seems to corroborate your 

 views. Last February (1925) we made 196 attempts to effect 

 self-pollinations and got only one fruit containing a single seed. 

 This one fiiiit was obtained from a seedling variety of which 24 

 flowers had been selfed. In all, 21 varieties were included in the 

 196 self-pollinations. We also made 22 crosses between seedling 

 No. 263 and Ipomoea Nil (L.) Roth, 20 between this same va- 

 riety and Qitamoclit coccinca (L.) Moench, but got no results in 

 either case." 



- The Sweet Potato, C. B. Brooks, Department of Agriculture and 

 Stock. Queensland. 



