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NOXIOUS WEED DEPARTMENT |
JOHNSON GRASS CONTROL PROGRAM |
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Description | Reduction | Control | Herbicides | Biological Control | Pictures |
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*Information provided by County Weed Directors Association of Kansas Johnson Grass is an upright perennial grass, reproducing by large rhizomes and seeds. It is well adapted to hold its own in competition with croplands. Stems are 6 to 8 feet or higher from a freely branching stout, rhizome-possessing, fibrous root system. Leaves are alternate, simple, relatively wide and long. The spikelets are 1-flowered, in groups of 3, in large open panicles. The fruit is a caryopsis or grain, finely striate, reddish-brown with two knobbed rachillae extending upward from the base of the seed. Johnson Grass flowers from May until frost and seeds to frost. Johnson Grass is one of the most costly weeds with which farmers must contend. It costs them millions of dollars each year in lost crops, poor quality grain and lower crop yields. Five Johnson Grass stems per .0001 acre reduces soybean yields by 4.2%; 50 stems reduces yields by 23%; and 340 stems, 88%. One Johnson Grass head per 3.3 feet of grain sorghum row reduces yield by 52 pounds per acre while 50 heads per 3.3 feet reduces yields by 50%. A single plant at maturity may produce over 80,000 seeds and more than 212 feet of rhizomes. Johnson Grass seed can remain viable in the soil up to 25 years. Preventing seed production and its spread is of primary importance. New infestations of Johnson Grass may be reduced by planting Johnson Grass free seed, using livestock feed that is free of Johnson Grass seed and cleaning machinery before leaving infested fields. Control of Johnson Grass shall mean preventing the production of viable seed and destroying the plant's ability to reproduce by vegetative means. Procedures to be used to control Johnson Grass shall include cultural control practices and chemical control or a combination of these two controls. Cultivation may begin anytime during growing season and shall be done in such a manner as to cut off all the weed plant at each operation (use duckfoot or blade type implement). Cultivations shall be 3 to 5 inches deep at intervals of 14 to 18 days. When the plants have been so weakened that they emerge more slowly, the cultivation intervals may be extended to such a time as will permit the plants to grow not more than 10 days after each emergence of first plants, but not to exceed intervals of 3 weeks. Cultivation shall be continued until the weeds have been eradicated or have been suppressed to such extent that remaining plants may be more economically destroyed by the application of approved chemicals to individual plants or by hand cultivation. In yards, flower gardens, lawns and among trees and shrubbery, hoeing and other effective means of thoroughly cutting the weeds at regular intervals, but not to exceed 14 days during the growing season shall be construed as intensive cultivation. A combination of small grains and intensive cultivation may be used. Close grazing or mowing at 2 to 3 week intervals through the growing season and followed by late fall plowing, to expose the root stalks through the winter, is an accepted control practice. The following herbicides may be used for cost-share with landowners. Other products labeled and registered for use on this noxious weed in Kansas may be used in accordance with label directions buy are not available for cost-share. Bromacil (Hyvar). DO NOT APPLY TO CROPLAND. Use for industrial sites and non-crop areas. Apply before or during active plant growth. Follow label directions and precautions. MSMA. DO NOT APPLY TO CROPLAND. Spray to wet foliage completely and apply during active plant growth. Follow label directions and precautions. Glyphosate (Roundup). For best results apply to actively growing plants when most have reached boot to head stages of growth. DO NOT apply after the plants turn brown in the fall. Allow 7 or more days between application and tillage. Follow label directions and precautions. Sulfometuron (Oust + nonionic surfactant). DO NOT APPLY TO CROPLAND. Apply pre-emergence or early post emergence to boot stage. Follow label directions and precautions. Trifluralin (Treflan). Apply Treflan at a 2x rate. Follow label directions and precautions. Fluazifop-P-butyl (Fusilade). Follow label directions and precautions. Sethoxydim (Poast, Poast Plus). Follow label directions and precautions. Fusion. Follow label directions and precautions. Arsenal. Follow label directions and precautions. There are no biological controls approved for Johnson Grass at this time. |