NOTES ON EECENT RESEARCH. 



193 



March 14, 1901.) — A contribution on combating weeds by spraying with 

 solutions of various salts. The following table gives results for sulphate 

 of iron, nitrate of soda, and sulphate of ammonia. In the original paper 

 details are also given for chloride of potash and chloride of magnesium in 

 30 p.c. and 15 p.c. solutions, and for other plants (Beet, Beans, Lupine, 

 Flax, and Equisetum). The various solutions were applied at the same 

 rate, 35^ gallons per acre. In the case of Wheat, Barley, Oats, and Rye 

 the plants were more or less injured by all the solutions, but recovered in 

 five to eight days : — 





Iron Sulphate 



Nitrate of Soda 



Sulphate of Ammonia 





20 p.c. 



30 p.c. 



15 p.c. 



30 p.c. 



15 p.c. 



Potatos .... 

 Peas .... 

 Vetches .... 



much 

 (lamageci 

 damaged 



>> 



killed 



u 



killed 

 undamaged 



killed 



killed 



slightly 

 damaged 



Clover, Old . . . 



Young . 

 Charlock (Brassica) ] 

 Runch (Raphanus) J 



much 



damaged 



killed 



slightly 

 damaged 

 >> 



killed 



slightly 

 damaged 



killed 



slightly 

 damaged 

 ) > 



killed 



undamaged 

 »» 



killed 



Thistle (Carduus spp.) 

 Sovvthistles (Sonchus spp.) 

 Sorrels (Rumex spp.) 

 Redshank (Persicaria) 



damaged 



slightly 

 damaged 



much 

 damaged 

 undamaged 



j> 



killed 



much 

 damaged 

 undamaged 



sHghtly 

 damaged 

 undamaged 



much 

 damaged 

 »> 



)> 



)» 



much 

 damaged 

 slightly 

 damaged 

 >) 



undamaged 



Knotgrass 



1 



undamaged 



>» 



undamaged 





Thistles, Sowthistles, Sorrels, and Docks, which were not completely 

 killed by the spraying, suffered only temporarily and recovered. — Tl'. G. S. 



Frosts and Fruit. 



Springr Frosts and Fruit Trees. By H. Miiller-Thurgau (Zcit. 

 f.Pflanz. bd. x. ht. 6, p. 335; figs. 1, 2,3; January 1901).— During 

 March 1900 the temperature near Ziirich, Switzerland, fell suddenly from 

 mild to sharp frost at night. The author had the opportunity of seeing 

 much of the damage which followed. Discoloured twigs and buds, and 

 the usual signs of damage by spring frost, were soon reported, but the 

 paper deals especially with injury to the flower-buds, which only becomes 

 evident when the crop of fruit fails. The injury to flowers of Cherry 

 presents an interesting series, from death of the whole bud to that of 

 parts only. The many specimens examined belonged to one of the follow- 

 ing groups : {a) Many of the flower- buds unfolded and produced no 

 flowers, the enclosing leaves were healthy but the flower parts were found 

 dead at the stage of development corresponding to the date of the frost ; (/)) 

 other buds had the enclosing leaves and the calyx unharmed, the remaining 



o 



