its production. Foi ex- 

 ample, \ ery excellent yields 

 ill sugar-beel seed are now 

 being produced in certain 



areas of the Pacific Xorth- 

 Wes\ where the 1 cm | x ■ i;i - 

 tures are sufficiently mild to 

 permit overwintering and 

 the longer summer photo- 

 periods are especially favor- 

 able. As a result of these 

 recent developments the 

 United States now produces 

 enough sugar-beet seed for 

 its own use. 



Onions also show a range 

 in sensitivity and adjust- 

 ment to photoperiod, not 

 only in flowering but par- 

 ticularly in bulh produc- 

 tion. Failure of certain 

 varieties to produce mar- 

 ketable bulbs in one locality 

 and their successful produc- 

 tion in another often resull 

 from their relative degrees 

 of adjustment to the photo- 

 periods prevailing in such 

 localities while grov. th and 

 bulbing should be taking 

 place. Because of this fact 

 attention must be given to 

 l he determination and selec- 

 tion of localities u here the 



Largest crops can be mosl 



economically and success- 

 fully produced. A.s in the 

 case of other types of plants, 

 testing the varieties under 



experimental conditions w ill 



give exact information on 

 their probable success or 

 failure with respect to the 



Many varieties of potato generally fail to ma- 

 ture the berrylike seed balls but do so when the 

 photoperiod is sufficiently long. 



13 



