1922.] 



Spotted Medick. 



647 



eluding a very high proportion of Spotted Medick. This refuse 

 is used by many farmers and put on the land and explains the 

 occurrence of Spotted Medick in large quantities in certain 

 localities, while it is absent in others, although soil and 

 situation are similar. 



Eradication. — Spotted Medick being an annual, eradication 

 is largely a question of destroying the fohage at an early 

 stage. Two methods are possible, wet and dry spraying. The 

 time of application of the spray and the conditions are most 

 important. For both wet and dry spraying the weather must 

 be dry, sunny and the air still. Wet weather or moisture 

 minimises the effect of the chemical used, while sunshine helps 

 considerably. The effect of the dry spray is to scorch the 

 tissue of the leaf, and finally to destroy it. 



To test the various chemicals used, only small plots 8 sq. yd. 

 were treated, and the result of these used for trial on a larger 

 scale. The sprays used were as follows : — 



Wet Sprays. 



2 per cent, solnti'-n 



Copper Su1p1)ate 

 Caustic Soda 



2.^ 



failiir(\ 



failuie, 

 unless a very large 

 quantity use-l wlion 

 P'asses wei"o seriously 



Sulphate DC Ammonia 



damaged. 



Drj/ Sprays. 

 Kainit. 



10 oz. per 8 sq. yards 

 r, 



" 1J 11 11 ?7 1' 



Nitrate of Soda. 



10 oz. per 8 s-q. yai-ds 



U 11 11 11 



Sulphate of Ammonia. 



12 oz. pel- 8 sq. yards. 

 10 „ „ „ „ 



11 '1 11 11 



^ ?i 11 11 11 

 7 



' V 11 11 11 11 



11 11 11 V -1 



5 



" 11 11 ,1 M -1 



failiD-e. 



not satisfiictory. 

 failurf\ 



stimulated growth of 

 Medick. 



all gave good residts. 

 The smaller quan- 

 titie-< \vei"e slower 

 acting. 



The sulphate of ammonia plots were the only successful ones 

 and they were repeated with the same result. The larger 

 applications showed quicker results, but the final result was the 

 same provided the distribution of the powder was carefully 

 done over the area under treatment. 



The result is most unsatisfactory when the weather is wet. 

 Sunshine is also an additional advantagfe. Even if the weather 



