SEEDS WEEDS. 



645 



plants. The experiment also showed that there was no advantage in 

 soaking beet seed prior to sowing, but in this case there was an actual 

 loss amounting to about 18 per cent. 



The effect of fertilizers on the germination of seeds, G. H. 

 Hicks (Proc. Amer. Assoc. Adv. Sci., 47 (1898), pp. 428, 429). — A report 

 is made upon a series of tests on the effect of various chemical ferti- 

 lizers on seeds of wheat, lettuce, radish, and crimson clover. The 

 authors conclusions are as follows: 



"One per ceut strengths of muriate of potash and sodium nitrate used as fertili- 

 zers are very detrimental to the germination of seeds, whether applied directly or 

 mixed with the soil. Fertilizers composed of phosphoric acid or lime are much less 

 injurious to germination than sodium nitrate or muriate of potash, and if not used in 

 excess may he harmless. Commercial fertilizers should not he brought into direct 

 contact with germinating seeds. The effect of treating seeds with chemicals before 

 planting is no index to the action of those chemicals when applied as manures to the 

 soil. The chief injury from chemical fertilizers is effected upon the young sprouts after 

 they leave the seed coat and before they emerge from the soil, while the seeds them- 

 selves are injured only slightly or not at all. It is highly improbable that potash, 

 phosphoric acid, nitrogen, or lime used as fertilizers actually favor germination." 



On the influence of humus acids on germination, R. Tolf 

 ( Tidskr. Landtman, 19 (1898), No. 22, pp. 387-390).— In order to study the 

 effect of free humic and ulmic acids on germination the author filled 

 four germination dishes with sand sterilized by ignition, moistening the 

 sand with distilled water. Four other dishes were filled with raw, 

 wholly undecomposed, but previously finely pulverized peat. The lat- 

 ter was taken 0.5 meter below the surface of a drained marsh and near 

 a ditch, so that its water content was not excessive: the sand in every 

 case contained more water after having been moistened than did the 

 peat. This was a typical Sm aland high-marsh peat, made up exclusively 

 of Sphagnum fuscum and Mriophorum rag in at tint, and had a decided 

 acid reaction. Four other dishes were filled with peat in which the tree 

 acids had been barely neutralized with chalk. 



In each of the 3 sets of germination dishes, prepared as described, 

 series of 100 seeds each of spring wheat, plumage barley, mammoth 

 spring oats, and Probster oats (outer seeds only) were sown, and kept at a 

 temperature of 18 to 20° C. for 5 days. At the end of this period the 

 lengths of the radical and the rootlet of each plant were carefully meas- 

 ured and the plants critically examined. The average results are shown 

 below: 



Effect of humus acids on germination. 



