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VAN Slogteken (E.). De Nematoden-Bestrijding in de Bloembollen- 

 streek. [The Combating of Nematodes in the Dutch Bulb- 

 growing Districts.] — Tijdschr. Pkmtenziekten, Wagenwgen, xxvi, 

 nos. 5, 7, 8, May, July, August 1920, pp. 118-138, 161-171, 177- 

 188, 4 figs., 3 plates. 



A detailed account of the infestation of flower bulbs by Nematodes 

 and of the measures advised against them is given. When the bulbs 

 are still in the ground and both ground and bulbs are infested, the 

 removal of affected bulbs with the earth surrounding them is the 

 measure advocated. If the ground is not planted, it should be turned 

 over so that the upper layer is buried ; an alternative method consists 

 in carefully removing the top layer to a depth of 7 inches, and putting 

 down clean sand before planting uninfested bulbs. 



Infested bulbs may be freed from Nematodes by immersion in hot 

 water or exposure to hot air. Care must be taken to do this at the most 

 favourable time and with the method best suited to the particular 

 bulb. Up to the present, for instance, hot water has not given good 

 results with hyacinths. 



All WOOD (M, C). Carnations — their Pests and Diseases. — Jl. 

 R. Hortic. Soc, London, xlv, no. 2-3, July 1920, pp. 233-236, 4 figs. 



The chief insect pest of carnations is Tetranychus telarius (red spider) 

 which usually appears in June, July and August, and may be eradicated 

 by syringing at very high pressure the under-sides of the leaves with 

 clear cold water and once every fourteen days with nicotine extract. 

 One application of nicotine preparation will destroy Aphids, and this 

 is also the most effective remedy against Heliothrips tabaci. 



Agriotes spp., Tylenclms dipsaci {devastatrix) (eelworm), Tipula 

 oleracea (leather-jacket grub), etc., may be reduced by treating the soil 

 in the spring. This includes ploughing from 4 to 5 inches and allowing 

 chickens to pick over the soil. For special seedlings the soil is sterilised 

 with steam. 



KussELL (E. J.). The Partial Sterilization of Soils. — Jl. R. Hortic. 



Soc, London, xlv, no. 2-3, July 1920, pp. 237-246, 7 figs. 



Partial sterilisation of the soil has been found to be an effective 

 and in some cases the only means of eradicating organisms noxious to 

 plants. Of the various methods tested, steam is decidedly the most 

 efficacious and reliable, as it kills all organisms and animal pests, and 

 also facilitates the work of beneficial organisms by bringing about a 

 certain amount of decomposition. Owing to the expense involved 

 with this method experiments have been carried out to find an efficient 

 chemical steriliser. The use of chemicals for this purpose is not only 

 cheaper, but also more convenient. It is most essential that the sub- 

 stance should disappear from the soil after its work is done. This 

 may occur by evaporation, oxidation or decomposition. The various 

 substances tested include carbon bisulphide, toluene, cresylic acid 

 (hquid carbolic acid) and chloropicrin. The latter is one of the best, 

 and proved fatal to eelworms and wireworms besides being harmless 

 to plants, but it is unfortunately very awkward and dangerous to 

 handle. 



