105G EXPERIMENT STATION RECORD. 



greenhouses, although not infrequently outdoor plants are subjected to 

 nematodes by being brought into contact with infested earth or 

 manure. At the station it was found that the eggs will not survive 

 the winter. The various means which were tested for destroying the 

 adult worms are reviewed at some length. The use of chemicals for 

 this purpose is of no practical value. While there are many chemicals 

 which will kill the adult worms yet the most effectual, complete, and 

 practical method for exterminating nematodes in greenhouses is by 

 sterilizing the soil by means of steam. This is best effected under a 

 steam pressure somewhat in excess of 50 lbs. The minimum amount 

 of heat necessary to kill nematodes and eggs when found in the soil 

 is about 140° F., but, for all practical purposes, it was found desirable 

 to make use of higher temperatures ranging from 180 to 212° F. This 

 steam sterilizing of the soil, in addition to destroying the nematodes, 

 killed many other greenhouse pests, greatly improved the mechanical 

 condition of the soil, and rendered the humus compounds more avail- 

 able for plant food, which resulted in giving the plants a considerable 

 acceleration in their rate of growth. 



Investigations on means for increasing adherence of fungicides, 

 J. Perraud (Compt. Bend. Acad. Sci. Paris, 127 (189S), No. 22, pp. 876- 

 879). — In order to ascertain the degree of adherence of a number of 

 fungicides, the author conducted a series of experiments with a solu- 

 tion of 2 per cent copper sulphate rendered slightly alkaline with fat 

 lime, 2 per cent copper sulphate and 2 per cent fat lime, 2 per cent 

 copper sulphate rendered slightly alkaline with slaked lime, 2 per cent 

 copper sulphate rendered slightly alkaline with sodium carbonate and 

 neutral copper acetate. To these different solutions a number of sub- 

 stances were added to render them more adherent. Among those used 

 were dried blood, the white of egg, gum tragacanth, glue, starch, dex- 

 trin, potassium silicate, molasses, aluminum sulphate, soap, and resin. 

 Eau celeste was also tested. After spraying these upon grape leaves 

 and fruits and allowing them to dry for 2 hours in the sun, both the fruit 

 and leaves were subjected to an artificial rain amounting to 4 mm. and the 

 percentage of copper adhering to them determined. The results show 

 that all the modern fungicides are less adherent to the fruit of the 

 grape than to the leaves. From the standpoint of their adherence the 

 fungicides tested are reported in the following order: (1) The solution 

 of copper sulphate made slightly alkaline with carbonate of soda; 



(2) the copper sulphate solution made slightly alkaline with fat lime; 



(3) the solution in which equal quantities of copper and lime were 

 used; (4) neutral copper acetate; (5) eau celeste and (6) copper sul- 

 phate and slaked lime. 



Of the substances used to increase the adherence of the fungicides, 

 resin was by far the best, followed by soap, potassium silicate, molasses, 

 gum tragacanth, and glue. The other substances employed either were 

 without apparent effect or seemed to diminish the adherence of the 

 fungicides. It is ascertained that the nature of the lime which enters 



