i8o Missouri Agr. Exp. Sta. Research Bulletin- No. 8 



Plant 



Gaillardia (G. pulchella) 



Chrysanthemum (C. Sinense) 



Sedum spectabile 



Dandelion (Taraxacum officinale) 



Dock (Rumex crispus) 



Verbena (V . hybrida) 



Hollyhock (Althaea rosea) 



Horse-radish (Cochlearia Armoracia) 



California Poppy (Eschscholzia Californica) , 



Clover (Trifolium pratense) 



Violet (Viola odorata) 



Cabbage (Brassica oleracea) 



Plantain (Plantago major) 



Strawberry (Fragaria Chiloensis) 



Depression 



.803 



1.955 



.575 



.975 



.997 



1.093 



1.130 



1.125 



1.198 



1.290 



1.225 



1.115 



1.380 



1.865 



All these depressions were determined as late in autumn as it 

 was possible to secure healthy tissue. 



While it is evident that other factors than sap density influence 

 the hardiness, yet it seems true that more of the very tender plants 

 are found among those with slight depressions, and a majority of 

 the most hardy among those with greater density. It is possible 

 that if a larger list of plants were obtained, this might not be true. 



All of these tests have been made with succulent plants that 

 kill at a temperature a few degrees below the freezing point. It is 

 true that some rather hardy plants like cabbage, kale, lettuce and 

 garden peas have been influenced in their killing temperature as great- 

 ly as have plants like tomatoes and cowpeas that kill at a tempera- 

 ture but slightly below the freezing point. However, in case of win- 

 ter wood, and buds that have developed great resistance to cold 

 by some sort of change, the problem would perhaps be difi"erent. 

 This experiment started with the idea that it might be possible to 

 increase the hardiness of buds of the peach in winter by increasing 

 the sap density through the use of fertilizers. Accordingly, plots 

 of peach trees at Dixon, Missouri, were fertilized with potassium 

 chloride at the rate of about 500 pounds to the acre, in the springs 

 of 1907, 1908, and 1909. Plots receiving potassium chloride at the 

 rate of a little more than 500 pounds to the acre during the seasons 

 of 1906, 1907, 1908, and 1909, were located in the orchard of the 

 Ozark Orchard Company at Goodman, Missouri; and plots receiving 

 480 pounds of potassium chloride to the acre, beginning March, 1910, 

 were located with the Ozark Fruit Farm Company, Brandsville 

 Missouri. Potassium was used in these experiments because some 

 experiments indicate that it is more readily taken into the cell to 

 become an osmotically active agent than most other mineral nutri- 



