EXPERIMENT STATION REPORTS. 241 



the disease-free lots in varital series and increase the highest yielder for 

 the general trade. 



A row series was run in 1!)22 representing the five hnndred and 

 sixty-five lots from Avhich the healthy tnbers came. This row-series was 

 checked with a tnber-line coming from the Upper Peninsula Experiment 

 Station. 



During the last winter a large nninbor of tubers from , the check 

 strain Avas also tested, and we were snr[)rised to find that a large por- 

 tion of these also developed disease under greenhouse test. The sixty- 

 one healthy tubers from the check strain are also planted in the 1928 

 tuber-unit series. 



There is also a row series planted in 1923 from the one hundred 

 and sixty-five units from which a healthy tuber was obtained as indi- 

 cated by greenhouse test. Tliis series, however, does not contain a check 

 because the check that we were using contains too niucli disease and 

 we have no other strain that is sufticiently increased to be used as a check. 

 These rows may be considered an increase, and if they prove, to be 

 healthy a varietal series can be set up, as soon as a healthy strain can 

 be increased sufficiently to be used as a check. 



RYE BREEDING. 



The table of projects shows seven different interests in rye breeding. 

 These have several cross relations. 



- In the first place we have a large number of strains coming from 

 selfed heads that are being isolated in order to obtain enough seed to 

 plant a row series in tlie fall. 



This row series will be planted from a i)ortion of eacli lot of seed. 

 The remnants Avill be saved for future planting. This process has al- 

 ready been run througli once and the remnants of the most desirable 

 lines are now under intercross. The thouglit is that selfing may reduce 

 the vigor somewhat, and that inter-crossing of the remnants will re- 

 turn the vigor. Selfing is necessarAr if definite characters are to be fixed 

 and certain others eliminated. 



In the fall of 1921 a large number of ryes were obtained from various 

 experiment stations over the country.' Our circular letter aimed to find 

 all of the ryes that are being recommended by experiment stations. 

 These ryes were included in a varietal series which also included a num- 

 ber of strains of Eosen. The series was repeated this year and will 

 be repeated the third year in order that we may find the better yielding 

 ryes for breeding purposes and that we may become intelligent regard- 

 ing the relative values of the various pedigreed varieties under Michigan 

 conditions. 



About five thousand individuals in each of the rye varietal series of 

 the past two years have been covered with little parafined envelopes 

 in order that the kernels produced on the heads would be self- fertilized. 

 The selfed heads of last year that contained reasonable numbers of 

 kernels of desirable quality produced the lots of seed that were isolated 

 this year for increase. The isolation was accomplished by planting 

 the lots two rods apart in the alleys of the wheat series and enclosing' 

 in cheese-cloth. 



