SEEDS WEEDS. 



759 



SEEDS— WEEDS. 



The influence of varying amounts of water on the germination 

 of beet seed, E. 8. Goff ( Wisconsin Sta. Rpt. 1897, pp. 299-302, figs. 

 2). — The author states that in testing seed in a Geneva tester he fre- 

 quently noted the influence of varying amounts of water in the cloth. 

 This is more apparent with beet seed than with other species which 

 have been tested. If the corky covering becomes saturated with water, 

 the oxygen may be so far shut out as to prevent germination. In order 

 to test the influence of varying amounts of water on germination a 

 series of experiments was conducted with 22 lots of beet seed from 

 various sources. In one apparatus the ends of the cloth of the Geneva 

 tester were constantly immersed in the water of the pan, the level of 

 which was slightly below the bottom of the pockets. In the other the 

 cloth was wrung out as nearly dry as possible without removing the 

 wires and placed in the empty pan and no further water was added. In 

 this apparatus provision was made against undue evaporation. One 

 hundred seed balls of the sugar-beet seed were placed in each pocket 

 and the 2 testers were placed in the horticultural laboratory, in which 

 the temperature varied during the test from 70 to 90° F. The average 

 germination from the 2 testers showed a difference of 50 plantlets for 

 each 100 seed balls in favor of the drier cloth. It would appear from 

 these results that the germination of beet seed in the open ground is 

 liable to be prevented by excessive water in the soil. 



Resistance of seed to immersion in -water, H. Coupin (Compt. 

 Bend. Acad. Set. Paris, 126 (1898), No. 19, pp. 1365-1368).— On account 

 of the importance of water as a factor in seed dissemination, the author 

 has made a study of the effect on the vitality of seed of their prolonged 

 immersion in water. Some of the injurious effects are pointed out, 

 notably the osmotic pressure of liquids in the cells, the loss of soluble 

 material in seed, the presence of bacteria which dissolve cellulose and 

 produce butyric fermentation, the lack of oxygen, and finally the attack 

 of various low organisms. In one set of trials the water was changed 

 every 24 hours, while in the other it remained unchanged from the 

 beginning of the experiment. The following table shows the length of 

 time seeds were immersed in water before their vitality was destroyed. 



• 

 Number of days within which seed vitality ivas destroyed by soaking. 



Kind of seed. 



Beets 



Mullein 



Leeks 



Asparagus 



Borage 



Anise 



Sweet fennel 



Poppy 



Flax 



Wheat 



Oats 



Millet 



16130— No. 8 



Kind of seed. 



White mustard 



Mallow 



Sunflower 



Stock 



Castor bean 



Harry vetch . . . 

 Crimson clo\ er. 



Cytisus 



Hemp 



Maize 



Buckwheat .... 



Water 

 changed. 



Days. 



110 

 20 



Water 



not 



changed. 



Days. 



