How Seedlings Get Established 



17 



been determined by trial for many kinds of seeds. 

 The following results were reported by the celebrated 

 German botanist, Julius Sachs:* 



EFFECT OF TEMPERATURE ON GERMINATION 



27. The Soil Should Be Warm before seeds are planted. 

 If the soil is cold, or has a temperature just above the 

 minimum temperature, germination will be slow, and 

 many seeds will rot before the seedling is established. 

 The soil should be considerably above the minimum 

 temperature before seeds are planted. The variation 

 in the minimum temperature required for germination 

 in different kinds of seeds explains why some seeds can 

 be planted much earlier than others. 



28. Effect of Temperature on the Promptness of 

 Germination. In some tests made by Professor Haber- 

 landt, it was found that the seeds of most of the small 

 grain crops required five to seven days to begin germi- 

 nation at 41 Fahr., while at 51 Fahr. only half the 

 time was required. At 65 Fahr., one day was sufficient 



*Julius Sachs, esteemed as the founder of modern plant physiology, was 

 born in Breslau, 1832, and died in 1897. The great interest aroused by the 

 results of his investigations on plant nutrition led to the establishment of one 

 of the first public institutions for the scientific study of agricultural problems. 



