considering the 3-year average yield. Common was consistently high in yield all 

 three years. Regrowth contributed substantially to seasonal yields. Three-year 

 average yields of 'Itasca' and 'Climax' were lowered considerably due to low 

 yields in 1973. TM 64-23 syn l('Champlaign') was relatively high yielding all 

 three years of the trial and was the highest yielding of the late entries in 1975 

 because of considerably higher first-cutting yields. 'Toro' was highest in yield in 

 1973, but lowest in yield in 1975. Although the stand was not substantially 

 reduced, the initial growth in 1975 was not vigorous. 



An important aspect of timothy yielding ability is vigor of regrowth. 

 Common timothy had the greatest regrowth as indicated by the highest second 

 cutting yields all three years of the trial. Except for TM 64-23 syn 1 

 ('Champlaign') the earliest entries were higher in seasonal yield than the latest 

 entries, largely as a result of superior regrowth. This might be expected, since the 

 earlier cutting would allow for regrowth before the onset of higher temperatures. 



Late-maturing varieties have been suggested for soils where timely harvest of 

 earlier varieties might be hindered by prolonged wetness or where other farm 

 operations prevent harvest of earlier varieties at the proper stage. Under these 

 conditions and where quality is considered, the late-maturing varieties might 

 compare more favorably. 



Lodging of the initial growth of timothy is common with high nitrogen 

 fertility. With the rates applied in this trial (50 lbs N/A in early spring) lodging 

 was not a problem in 1973 or in 1975; however, in 1974 lodging was quite 

 extensive and occurred, to some extent, on all entries. 



Stand survival, as indicated in Table 4, was generally good and continued high 

 yields could be expected among the earliest entries, however, later entries 

 thinned to a greater extent. In the more thinned out plots broadleaf weeds were 

 quite prevalent. Greater loss of stand among the later entries might have resulted 

 from poorer regrowth and more competition from weeds during the 

 mid-summer. 



Smooth bromegrass 

 Test I (Table 5 and 6) 



Yields given in tons/acre at 12% moisture, were reasonably good from this 

 trial in 1970 and 1971, but were unusually low in 1972 and 1973, despite the 

 fact that the stand was still good on most entries in 1973. During 1972 and 

 1973, there were deficits in rainfall in mid-summer which may have been a 

 factor, especially since the soil at this site is relatively thin and inclined to be 

 droughty. Also, vigor of the grass seemed rather low, despite heavy fertilization, 

 and the area may have become sod-bound. 



Relatively small differences in yield were noted between the syn one and syn 

 two generations. Synthetics based on relatively few parental clones, as here, 

 often tend to express maximum heterosis in the first generation of synthesis, 

 with a decrease in yield in generation two. In two different trials, the five clone 

 synthetic yielded slightly more in the second than in the first generation of 

 synthesis, contrary to expectation. 



Relatively few significant differences were obtained among entries in mean 

 yields. The very low yield of Sac in 1970 is due to the late (September 15) 



