77 



Method for producing immediate Germinatio 



^* Hardcoatcd '' Seeds, 



By R. S. FiNLOW and C. J. Bbrgtheil. 



Tlie recent snbstitation of the Java-Natal variety of Indigo 

 (Indigofera arret ta) for Indigofera sumatrana in Bihar, was at 

 first hinderedby the fact that the seed of L arrecta possesses a hard 

 coat which prevents an even germination unless it is treated, before 

 sowing, in such a way as to break through the outer resistant 

 material. This difficulty was originally surmounted by Mr. E, F. 

 Watson of Muzaffarpur, who invented a machine in which the 

 hard coat was scratched so that water could penetrate it and cause 

 the seed to germinate. Latterly, a chemical method has been 

 successfully introduced by one of us (C. J. B,), viz,, treatment of the 

 seed with concentrated sulphuric acid until the hard coat is dis- 

 solved. This method, which was probably first used in India by 



Dr. B. J. Butler, the Imperial Mycologist, in some experiments with 

 cotton seed, has now been applied to the seed of a series of wild fibre 

 plants with satisfactory results. The treatment is simple, con- 



sisting, as it does, merely in immersing the seed in concentrated 

 sulphuric acid for a sufficiently Jong period and subsequently 

 washing it in water. After drying, it is ready for sowing. Dif- 

 ferent seeds vary widely in the length of treatment with sulphuric 

 acid which they require; but the correct time can easily be gauged 

 by one or two preliminary experiments on a small scale. 



It would appear from the results given in the following table 

 that the development of a hard-coated seed is very common in 

 jnngle plants ; also that treatment with sulphuric acid is a 

 generally effective method for dissolving the resistant material 

 composing the hard coating : 



Name of plant 



• « ■ 



• *• 



m ■ 



Indigofera arrecta, HochsL 

 Pentapetes plioenicea, Linn, 

 Hibiscus pandaraeformis, Burnt, ,,. 

 Abatilon iiidicnm, SiveeU 

 Sida rbombifolia, Linn, 

 Corchorns, spp 

 Sida humilis, Cav, 

 Urena sp. 



Corchorus olifcorins, Willd, 

 Melochia corchorifolia, Linn, 

 Corchorus acutangnlns. Lam* 

 Hibiscus ficnlnens, Cav, 

 Malvastrutn tricuspidatum, Oray .. 

 Deamodium pnlcherrimam, Shut- 



tlew. and Chtseb, 

 Melilotaa alba, Desr, 



# * « 



■# * ■ 



• «* 



* v» 



Germination 



capacity 

 before treat- 

 ment- 





37o 



nil 

 nil 



ml 



nil 



15 7o 

 nil 



io;/o 



nil 

 nil 

 nil 

 nil 



i7o 



Period of 



treatment in 



honrs. 



i 



8| 

 2i 



2 

 1 



3 



2 



4 



2 



40 minutes 



Germination 



capacity after 

 treatment. 



95 7o 

 92 7„ 



75 7, 



60 7o 

 90 7, 



80 7o 



50 :/o 



] 00 7„ 

 100 7, 



81 7„ 



85 7, 



85 7, 

 66 7. 



90 7. 



