BARLEY C 



On the left are plants grown from seeds harvested only six days after thev were pollinated; on the right arc! 

 old weighs only 5 milligrams, instead of 35 milligrams for a normal adult grain. The small seedlings, although i 



THE GERMINATION OF BAR- 

 LEY SEEDS HARVESTED 

 AT DIFFERENT STAGES 

 OF GROWTH 



Harry V. Harlan 



AND 



Merritt N. Pope 

 Bureau of Plant Industry, United States Department of Agriculture 



AT ABERDEEN, Idaho, where 

 these experiments were conducted 

 under irrigation, in cooperation 

 with the Idaho Agricultural Experi- 

 ment Station, a kernel of Hannchen 

 barley is normally mature at 26 days 

 after flowering. In 1920 an experiment 

 was undertaken to determine the 

 earliest date after pollination at which 

 seeds were sufficiently developed to 

 germinate. In this experiment samples 

 from seven varieties were taken. Three 



of these varieties were six-rowed and 

 four were two-rowed. Sufficient spikes 

 of equal development were tagged in 

 each variety. The dates of flowering of 

 the spikes were determined by obser- 

 vations and later checked by measure- 

 ments of the kernels. These dates are 

 not absolutely accurate as the flowers 

 on a spike are not all fertilized on the 

 same day. In all varieties the tip and 

 basal flowers are pollinated later than 

 those on the central part of the spike. 



72 



