SUMMER FROSTS AXD THEIR EFFECTS, ETC. 293 



Summer Frosts and their Effects on Swedes and Mangels in 

 the North of England. By Prof. D. A. Gilchrist, 



M.Sc. 



Read June 3RD, 1905. 



As summer frosts (on the grass) are very prevalent in the 

 north-east of England, the writer has endeavoured to find 

 whether there is any connection between these and the 

 variation in the composition of swedes from year to }'ear, 

 and also to note what eifects these may have on the mangel 

 and swede crops of the north of England. All the frosts 

 tabulated are taken from the records of the minimum night 

 temperatures registered on the grass, and not at four feet 

 above the ground as is usually done. The former are generally 

 lower than the latter. 



The following table gives the summer frosts at Cockle Park, 

 Northumberland, during the summers of 1900-1904, as well 

 as the variations in amount of dry matter, and in the feeding 

 value of swedes grown at that centre in these years : — 

 Frosts on grass (degrees Fahrenheit) 324 feet above sea level. 





1900 



I90I 



1902 



1903 



1904 



June... 



3rd i' 



7th Q-I^ 



nth i^ 



3rdo-i° 



None 







19th 3° 



iSth 1° 



14th 2° 

 19th 2"' 

 20th 1° 



2ISt 2° 





July 



None 



None 



25th i^ 



20th l" 



None 



August 



None 



i7ch i^ 



None 



None 



None 



September ... 



25th 2^ 



2nd o-i^ 



19th I" 



i6tho-i^ 



2ISt 0-5 



October (first severe 













frost) 



5th 5^- 



loth y- 



Sth 4-^ 



nth 3= 



ijlh 5'^ 



Percentage of dry- 













matter in swedes 



■=11-43 



10-32 



11-93 



11-67 



14-96 



Comparative value of 













swedes per ton 













(average S -) ... 



7 7 



6'io 



7'" 



7/9 



10,'- 



Approximate crop per 













acre 



25 tons 



20 tons 



22 tons 



21 tons 



26 tons 



Freezing point is 



32"^ F. 



In the foregoing 



table the 



numbe 



of degrees of frost is given and not the temperatures as 

 recorded. These are given for each night that frost occurred 



* Analyses of Mr. S. H. Collins, F.C.S., Ai-msti-ong College, Kewcastle-iipon-Tvno. 



