112 



GRASSES OF IOWA. 

 TABLE No. XIV. 



VITALITY OF TIMOTHY SEED. 



Morrow and Hunt, from sixteen seedsmen. . 



Parsons, summary of American tests 



Tests at various stations 



McCarthy, standard for choice seed 



U. S. Department of Agriculture, standard 



16 

 51 



48 



42 







30 



76 



80.1 



91.48 



89 



85-90 



96 

 100 

 100 



These figures show that the timothy seed is improving in 

 vitality and that the average sa^nple now exceeds the standard 

 once set for choice seed. It is much to be hoped that the next 

 ten years may bring about a similar improvement in the seeds 

 of other species. 



Diseases of Germinating Cereals. 



Moulds. — The most serious difiiculties which corn and other 

 grasses have to contend against in germinating are moulds and 

 bacteria. The following moulds are commonly found: The 

 common blue mould (Penicillium glaucum), green mould {Euro- 

 tium {Aspergillus) glaucus) and black mould (Bhizopus nigricans). 

 Cladosporium, Macrosporium and Sterigmatocystis may occur 

 occasionally, but they are not generally common. 



Haberlandt, who made a study of the mouldy rye and its ger- 

 mination, found a gradual decline in its germination as the seed 

 became older. 



Logewall, who had observed that rye seed rapidly loses in 

 its p )wer of germination, especially in damp and warm weather, 

 attributes this to micro-organisms. In the case of wheat, bow- 

 ever, this did not appear to make any difference. As a result 

 of his rye experiments he determined as follows: 



One hundred rye kernels without infectijn, germination 100 

 per cent; 100 rye kernels with infection, germination 98 per 

 cent; 100 rye kernels injured without infection, germination 97 

 per cent; 100 rye kernels injured with infection, germination 91 

 per cent. 



C. Rambousek,t states that moulds of damp seeds destroy 

 the germinative energy to a considerable degree and its distruc- 

 tive influence is most severe on barley. 



•WlsseaschaftUch praktlsche Dnters aut dem Geblete des Pflanzenbaues. 1: 66-68, 

 1875. Harz. Landw. Samen Knude. 1 : 294. 



tPrager. Landw. Wochenblatt. 1895; 393. Bledermann's Centr. Agrtkulturch. 24: 

 393. 



