noticeably poorer than the rest. Somewhat higher yields were obtained in 

 grass mixtures with Minnesota synthetic and Vermont polyploid as shown 

 by their yield in the bromegrass mixture. Presumably, this is because of 

 the fact that grasses generally produce more dry weight than Ladino 

 clover, and plots with sparse clover stands contained more bromegrass. 



There was no differential kill of the white clover strains in this test 

 during the severe 1958-59 winter, probably because of the excellent snow 

 cover at this location. 



Results for white clover test # 3 are shown below in Table 7. 



Table 7. Forage Yields of Seven Strains of White Clover, 



Seeded Alone and with Bromegrass at Dover, New Hampshire, 1958. 



(tons per acre at 12 percent moisture) 



* Based on three visual estimates of clover in mixture during 1958. 



Good stands were obtained on all strains except Synthetic #: 2, developed 

 at the U. S. Regional Pasture Laboratory at State College, Pennsylvania. 

 This strain was intermediate in size, flowered profusely, and was somewhat 

 earlier in maturity than the other strains. It began flowering approximately 

 May 29. and all other strains began about June 10. In general, strains of 

 white clover which flower heavily usually produce less forage, and selec- 

 tions in the breeding program at this Station have generally been in the 

 direction of lower flower production. There is also some evidence that the 

 most floriferous strains are less persistent than the least floriferous. 



Oregon Ladino and Pilgrim produced somewhat higher yields in pure 

 stands in this test, while in mixtures the former had the highest percent 

 of clover. 



The clover was completely winter-killed during the severe winter of 

 1958-59 at this location as well as many others in southern New Hamp- 

 shire. The winter was abnormally cold and extensive ice-sheeting occurred. 

 No data were obtained on differential survival of the strains in this test. 



Studies at Michigan (5) and New Hampshire (2) have shown that the 

 primary taproots of white clover rarely live more than about two years. 

 Numerous soil-borne fungi and insects may be associated with the rapid 

 death of the root system. Yields are usually drastically reduced in the 

 second and third production year, as shown in Table 6 in the column for 

 Ladino alone. Basic physiological and chemical studies, are needed before 

 substantial improvement can be made in the persistence of this important 



legume. 



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