SEEDS WEEDS. 883 



The author gives some notes on the French weed (Thlaspi arvense), in which it is 

 shown that seed of this weed remaining in |><>ds out of doors over winter is usually 

 dead by spring. Plants with green seed pods plowed under ripen their seeds much 

 quicker than those left above ground. The ripened pods occur on this weed 77 days 

 from sowing and 34 days from flowering. This weed is must injurious when it starts 

 in the fall of the year, being a pernicious plant only as a winter annual. If the seed 

 bed of the grain field is well harrowed before seeding, or if the land is spring plowed, 

 French weed will not he troublesome in grain fields. 



Notes are given on the relative aggressiveness of different weeds, the author hav- 

 ing planted 800 seeds each of Russian pigweed, tumbling mustard, wild mustard, 

 French weed, false flax, and ball mustard. These were planted .May 111, 191)4, and 

 on July 1 the wild mustard showed the most abundant leaf surface, with false Max 

 next. On July 19 the plants had attained their maximum size and all, were pu lied 

 and counted, and the relative a<_ r L r ressiveness determined. The number of plants of 

 each kind produced from the SOI) seeds was as follows: False flax 520, wild mustard 

 356, Russian pigweed 281, hall mustard L95, French weed 24, and tumbling mustard 

 3. This experiment shows the weakness of some species when in competition with 

 other rapid-growing plants. 



Notes are given on the distribution of a number of weeds throughout the State, 

 illustrations showing the root stocks of quack grass, and suggestions for the eradica- 

 tion of thistles. 



The combating- of weeds, P. Trubenbach {Fulding's Landw. Ztg., 53 (1904), 

 Nos. 20, pp. 749-756; 21, jj}>. 798-805 ).— The effect of the growth of weeds upon crop 

 production is discussed, and the results of extended investigations are given. 



Tables are presented showing the effect of weeds on the reduction of soil tempera- 

 ture and moisture and yields of various crops. The average soil temperature from 

 June 27 to July 2 in areas of beets, potatoes, beans, and maize where weeds were 

 allowed to grow show'ed a reduction of from 2 to 4° C. through the extra shading 

 and transpiration, as compared with similar areas, where the weeds were kept down 

 by thorough cultivation. The water content of the soil at the same time diminished 

 by an average of about 2 per cent on the weedy plats. 



The greatest reduction is noted in the diminished yields attributed to the growth 

 of weeds, in one series of experiments the reduction in the yield of peas, vetches, 

 and beets was from l~> to 20 per cent, while beans, potatoes, and maize were reduced 

 from 45 to *>•> per cent. In another series the results were even more striking. 



The seed habit of a number of weeds is discussed, the distribution of the seeds in 

 the soil and characteristics of different species of weeds are described, and methods 

 of eradication are suggested. Clean cultivation and rotation of crops are recom- 

 mended and a number of rotations are outlined. 



Destruction of charlock by spraying, R. S. Ski ox | Yorkshire Col., Leeds, and 

 Yorkshire Council Agr. Education, [Pamphlet] 30, 1903, \>\>. S). — Charlock is said to 

 be so abundant in parts of England as to make its eradication of j^'fat importance. 

 The growth of the weed with fallow crops is not liable to result in seeding the 

 ground, consequently attempts should he made to prevent its seeding in ^rain 

 crops. 



Demonstrations have been carried on in Yorkshire during the past 4 years which 

 have shown that spraying, properly conducted, is both the cheapest and most 

 effective way of dealing with charlock in grain. For the eradication of the weed 

 the author suggests spraying while the plants are young, using either a copper sul- 

 phate or iron sulphate solution. The majority of the trials have given the best 

 results where iron sulphate was used. If copper sulphate is used it should be applied 

 at the rate of 12 lbs. to 40 gal. of water, or if iron sulphate is used 60 His. to 40 gal. 

 When these solutions are used in these strengths there is no permanent injury to the 

 cereal crop. 



