Weed FIELD 3.* Date Small ragweed smartweed Green foxtail Mar. 29 Apr. 6 Apr. 13 Apr. 20 Apr. 27 May 4 *On corn land that had been fall plowed. Field worked up and sowed to small grain just before April 27. FIELD 4.* Weed Date Mar. 29 Apr. 6 Apr. 13 Apr. 20 Apr. 27 May 4 Yellow foxtail Green foxtail Mar. 29 Apr. 6 Apr. 13 Apr. 20 Apr. 27 May 4 599 718 Daisy fleabane Peppergrass Pennsylvania smartweed Spurge "On old corn land. Stalks harrowed down just previous to April 20. Mar. 29 Apr. 6 Apr. 13 Apr. 20 Apr. 27 May 4 *On fall plowed oats stubble. Mar. 29 Apr. 6 Apr. 13 Apr. 20 Apr. 27 | May 4 FIELD 8.* Weed Small ragweed Date Mar. 29 Apr. 6 Apr. 13 Apr. 20 Apr. 27 May 4 Self-heal *In sheltered place on the south side of the railroad grade. Weeds were not all counted on April 27th, but there were hundreds of small ragweeds and smartweeds, and probably more than a thousand green foxtail plants. ++Winter annual. + Perennial. These tables reveal some interesting facts. The first weeds to appear in March were the winter annuals, like peppergrass and shepherd's purse, certain perennial weeds, and in one case horseweed (Erigeron canadensis) in a timothy meadow. Two weeks later smartweed (Polygonum) was abundant. Spurge (Euphorbia), an annual, was abundant in the latter part of April and early May. Foxtails in some cases surpassed all other weeds in abundance early in May. The smartweeds (Polygonum) and spurges increased enormously. These weeds were entirely removed from the plots. Fall plowing and clean cultivation certainly indicate a smaller number of weeds. Long, who measured off a square yard of ground in Great Britain, roughly grouping its plant life therein into species, found on this square yard 1,050 seedlings or 5,082,000 per acre. There were 654 buttercup seedlings, 107 of annual meadow grass, 60 of dock, 26 of goose foot, 25 of groundsel, 15 of shepherd's purse, 14 of *Trans. of Highland Agri. Soc. Scotland V. 23: 52. FIG. 515. A weedy cornfield, mostly Foxtail and Smartweeds. (Photographed by Colburn.) annual sow thistle, and 10 of chickweed, besides 139 of other species. He states that Korsmo's investigation revealed the presence of an even larger number of seeds having the power of germination, the seeds per square yard to a depth of 9.8 inches being as follows: Fallow field, 8,682 weed seeds (over 42,000,000 per acre); field for spring grain bearing the same crop for four successive years, 28,213 weed seeds (over 136,000,000 per acre); fallow field, 1,474 weed seeds (over 7,000,000 per acre). Mr. Long gives the following species of weeds found in Great Britain within an area 100 feet square: |