The Effect of Certain Organic Compounds on Wheat Plants in the Soil—Preliminary Paper.

Abstract

or without t h e persulfate treatment for steels of over 0. j o per cent carbon.T h e ferrous ammonium sulfate solution m a y be standardized against 0.1 N perrnanganatc, the strength of which has been determined with sodium oxalate. T h e iron value of the permanganate multiplied b y 0.917 gives the vanadium value. By this method t h e following results were obtained, the chromium in expts. 9, I O , 13 and 14 being added as KzCrlOl before the solution of the steel.T h e following steels were employed:-U. S . Bureau of Standorde Sample h70. 24, containing 0.15 per cent B-U. S. Bureau of Standards Sample No. 30, containing 0.21 per cent C-A steel casting confaning 0.2 IS per cent V. 0.30 per cent C. and no Cr. D--A plain steel containing 0.85 per cent C. V. 11.35 per cent C. and a trace of Ci. V. 0.37 per cent C. and 1.35 per cent Cr. Ti-'1 plain steel cootnining 1.25 per cent C.

The History of Allelopathy

“…Fraps concluded that results from pot experiments differed markedly from those in aqueous culture. Funchess (1916) also reported on the effects of various supposed soil toxins in pot experiments with oats and corn and his results concurred, generally, with those of other workers (Dandeno 1910;Fraps 1915;Upson and Powell 1915). Lyon and Wilson (1921) attempted to confirm whether plant roots do indeed release organic matter and whether any of these substances do become oxidising or reducing.…”

“…Fred (1912) found that "toxic" soil could not be amended through sterilising agents such as ether. Upson and Powell (1915) at the University of Nebraska investigated the effects of the putative toxins vanillin, salicyclic aldehyde, coumarin, quinone and dihydroxystearic acid in soil experiments but found little inhibition of seedling growth. Fraps (1915) found that dihydroxystearic acid administered at 500 ppm to corn and sorghum plants in pots had little effect.…”

The USDA Bureau of Soils and Its Influence

“…Work on soil aldehydes was taken up by several investigators (Davidson 1915;Fraps 1915;Funchess 1916;Upson and Powell 1915) and this work led to an understanding of the degradation of these compounds in soil (Gardner 1924(Gardner , 1926Robbins 1916Robbins , 1917Robbins and Lathrop 1919). Fred (1912) found that "toxic" soil could not be amended through sterilising agents such as ether.…”