Poison ivy and similar woody-rooted pests can be eradicated by cutting off the tops in hot, dry weather in midsummer and pouring a saturated solution of caustic soda about the roots. The arsenical solutions mentioned above can be used, but are generally objectionable because they render the soil sterile for so long a period thereafter.

Prickly lettuce (Lactuca Scariola), called also milk-thistle, English thistle, and compass plant. Biennial or annual. Mow the plants repeatedly as they first begin to blossom. Thorough cultivation with a hoed crop is most effective. Mow and burn mature plants. Most frequently introduced as an impurity in clover, millet, and the heavier grass seeds.

Bracted plantain (Plantago aristata). Annual. Employ hand pulling and burning. If well established, a series of hoed crops may be necessary to eradicate. In permanent pasture, mow the plants as the seed stalks first appear.

Horse nettle (Solanum Carolinense). Perennial. Keep the plants mown to prevent seed production. To destroy the roots, practice clean cultivation and grubbing or spudding to prevent any development above ground. A thick growth of grain will weaken the roots. After the grain is cut, the land should be immediately plowed and harrowed repeatedly, and then sown to a winter crop. Then follow with a hoed crop.

Buffalo bur (Solanum rostratum). Annual; subdued by preventing seed production by mowing as often as the yellow blossoms appear.

Spiny amaranth (Amarantus spinosus). An annual, subdued by preventing seed production by thorough cultivation, mowing, or grubbing out the plant before the flower spikes develop. An intertilled crop followed by a winter crop will keep down the weed.

Spiny cocklebur (Xanthium spinosum). Annual; may be choked down by any quick-growing crop that will crowd and shade it. In permanent pastures and waste places mow the plants twice a year, in

August and September, or cut them out with hoe or spud in May and June.

Chondrilla (Chondrilla juncea). Biennial. Destroyed by cultivation and fertilizers to encourage the growth of desirable grasses.

Wild carrot (Daucus Carota). Biennial. In permanent pastures, mow persistently as the flowers appear. Cutting the roots well below the surface and hand pulling are effective. Thorough cultivation subdues it.

Wild oats (Avena fatua). Annual. Stir the land when it is warm and moist to cause the seeds to germinate, then cultivate to kill. Keep the ground occupied or stirred. Omit oats from the rotation. Plow shallow in late fall. In the spring, plow deep and summer fallow, keeping the ground clean. Plant to grain the next season without replowing. Then plow deep early the next fall. Then repeat the fallow, followed by grain two years later, again without replowing.

False flax (Camelina sativa). Annual. Omit winter wheat and rye from the rotation, and raise crops that will permit full cultivation. Hoed crops are best, as they induce the seeds to germinate. If well established in permanent pastures, plow and cultivate the land.

Mustard, Charlock (Brassica Sinapistrum). An annual, destroyed by early cultivation. Destroyed by spraying, when the plants are just beginning to bloom, with iron sulfate, copper sulfate, common salt, and sodium arsenite. Use 75-100 pounds of iron sulfate in 52 gallons of solution per acre; of copper sulfate, 12-15 pounds to each 52 gallons of water; common salt, 1/3 barrel to each 52 gallons of water; sodium arsenite, 11/2 pounds to each 52 gallons of water. Spray after a rain, or in a wet season on a bright, still day.

King-head, Greater ragweed (Ambrosia trifida). Annual. Cultivate to cause seed germination a sufficient time before cropping to allow the killing of the weeds by a subsequent cultivation. If the weeds are large on summer fallow, plow them completely under or collect and burn. Spray, when the plants are tender, with common salt, copper sulfate, iron sulfate, or sodium arsenite at the same rate and strengths as for mustard, except that at least 100 pounds of iron sulfate should be used for each 52 gallons. Throw the spray forcibly.