152 FOE AGE PLANTS AND THEIR CULTURE 



to select early, medium and late varieties, each with the 

 following combination of characters : 



1. Highest yield; 2. tall growth; 3. good stooling 

 capacity; 4. culms numerous and dense; 5. erect, 

 without tendency to lodge; 6. numerous large leaves; 

 7. culms leafy to near the top ; 8. tendency to remain 

 green late ; 9. rust resistance in high degree ; 10. heads 

 medium sized and bearing abundant good seed. 



140. Comparison of vegetative and seed progeny. 

 When timothy is propagated vegetatively, the progeny 

 are identical, at least in the great majority of cases. When, 

 however, the seed of a single plant is sown, the offspring 

 show considerable diversity. Webber has compared 

 the average yield of selected plants with that of their 

 descendants grown both clonally or vegetatively and from 

 seed. In the latter case some of the plants were grown 

 from open-fertilized and others from self-fertilized seed. 

 The average yield to the plant for all types tested was as 

 follows : original plants, 9.307 ounces ; clons or vegeta- 

 tive offspring, 8.769 ounces; open-fertilized seed 6.963 

 ounces ; self-fertilized seed, 5.243 ounces. These data 

 seem to indicate that self-fertilization tends to reduce 

 vigor. 



In another series of investigations the yield of clonal 

 individuals was compared to that- of seedlings from the 

 same parent. In all cases the seed-propagated plant 

 yielded less than the corresponding clon. A comparison 

 of the average yields, however, shows that as the yield 

 of the clons of an individual was high or low, so was its 

 corresponding progeny produced from inbred seed. The 

 increase in yield, however, from the lowest to the highest 

 was relatively much less in the seed-propagated plants 

 than in the clons. 



