THE AMERICAN BOTANIST 17 



The experiment stations have not been able to show that 

 it is profitable to use large tubers of sweet potato for seed.- 

 A great deal of work has been done on sweet potatoes by ex- 

 periment stations in both the North and South. Plant dealers 

 know that some ^"arieties have very much greater power to re- 

 produce than others, and they charge accordingly for tubers 

 which are to be used as seed. 



New varieties of tomato are being discovered each year. 

 Yields vary from 100 to 800 bushels per acre in the field. 

 Great advances have been made in raising tomatoes under 

 glass. It has been found that the English varieties are best 

 for winter use and the American type for large spring fruits. 

 The Engilsh variety Comet, which is small and adapted to 

 dark weather, will produce 5 to 6 pounds per plant. The Peer- 

 less — an American variety — will produce 11 to 12 pounds of 

 fruit per vine. 



Plant Breeders have done a great deal to increase the 

 production of field crops but there is eight times as much pro- 

 fit in vegetable growing as there is in general farming, ac- 

 cording to census reports. Therefore it behooves the growers 

 to make the breeders work for them, to help increase produc- 

 tion. The greenhouse crops show the results of intensive 

 study by breeders, and a like improvement is possible with all 

 the vegetables. It is of great economic importance to make 

 use of every bit of information gained by scientists which will 

 help increase production. The grower himself will gain, and 

 the world demands this efficiency in production which will in- 

 crease the supply of food-stuffs. 



