NEW EVERBEARING STRAWBERRIES 



W. Van Fleet 

 Bureau of Plant Industry, United States Department of Agriculture 



SEVERAL varieties of strawberries 

 that continue under favorable 

 conditions to fruit throughout 

 the summer and autumn after 

 bearing a fair spring crop of berries 

 have lately come into favor. All are 

 descendants of the Pan American, a 

 sport or mutation of the BismacK, a 

 former commercial variety of the Fra- 

 garia virginiana type in which the run- 

 ners are to a great extent suppressed, 

 favoring the successional production of 

 fruiting crowns during the growing 

 season. This peculiarity appears herit- 

 able in many seedlings and hybrids of 

 Pan American, and the horticultural 

 section thus established has been given 

 the convenient but somewhat mislead- 

 ing name of "everbearing," as special 

 cultural requirements in the way of 

 moisture and fertilization are needed to 

 insure fruit formation and plant in- 

 crease during the most exacting sum- 

 mer months. Progressive and Superb 

 are the most popular varieties of the 

 new type and are increasingly planted. 

 They leave something to be desired in 

 productiveness and plant-making capac- 

 ity, as few runners are thrown out from 

 the more prolific plants. Seedlings con- 

 tinue to be grown from the present ever- 

 bearing varieties, and crossings have 

 been made by several growers with 

 spring-fruiting commercial varieties 

 and varieties of the European Alpine 

 strawberry Fragaria vesca, which nat- 

 urally fruits over a long season, in the 

 hope of developing features of addi- 

 tional value. Fragaria vesca in the 

 European and Mexican Alpine forms 

 has rarely proved worth cultivating in 

 North America, as the plants do not 

 well endure our hot sunlight and the 

 berries, though well flavored, are small 

 and soft in texture. 



While traveling in Chile as an agri- 



14 



cultural explorer in 1914, Prof. W. F. 

 Wight, of the Bureau of Plant Indus- 

 try, forwarded seeds of a fairly large- 

 fruited Alpine strawberry occasionally 

 sold in the Santiago markets. The 

 type is that of Fragaria vesca, but 

 whether native or introduced could not 

 be ascertained. When grown in the 

 introduction gardens at Rockville, Md., 

 and Chico, Cal., of the Office of For- 

 eign Seed and Plant Introduction, cer- 

 tain of the resulting plants showed 

 greater vigor, fruitfulness and general 

 adaptation to our climatic conditions 

 than any Alpine hitherto introduced. 

 They have endured our hot, dry sum- 

 mers, fruiting continuously from June 

 until frost under the most ordinary cul- 

 tural treatment, at the same time throw- 

 ing out an abundance of strong runners. 

 The berries are well flavored, but lack 

 firm texture and sufficient size to be of 

 practical value. Plants have been dis- 

 seminated in a limited way for further 

 trial under the introduction number of 

 35005. The ability of this South Amer- 

 ican strawberry to fruit and produce 

 runners simultaneously throughout the 

 summer and autumn suggested the pos- 

 sibility of developing large-fruited vari- 

 eties holding the same characteristics 

 by hybridizing it with practical com- 

 mercial spring-bearing sorts. Chesa- 

 peake and Early Jersey Giant were 

 selected for the purpose as being well 

 adapted to local conditions at Bell Ex- 

 periment Plot, Glendale, Md. Pollina- 

 tions were carefully made under glass 

 in February, 1916, and the resulting 

 seedlings grown in the field. About 

 400 fruited in June, 1917, showing high 

 average merit as June-fruiting varieties, 

 but with no obvious tendency toward 

 continuous bearing. 



Runners from two of the best plants 

 were rooted in pots during summer, 



