Browse on keywords: weed herbicide
Search results on 05/24/13
356. Anon.. 1989. Fine-tuning mix water.. Agrichemical Age, October 1989.
Herbicide performance can be greatly affected by the quality of the tank mix water. Water-soluble post emergent herbicides, such as glyphosate and phenoxys, seem to be most sensitive. Three factors are important: water pH; cation concentration; and suspended solids. Post-emergent herbicides perform best when the tank mix is acidic. Optimum for phenoxys and glyphosate is pH 3-4. Hard water will reduce activity when herbicides are mixed and stored for many hours. Cation effects on deactivation are as follows: most severe - Fe++, Fe+++, Al+++; severe - Ca++, Zn++; moderate - Mg++; minimal - K+, Na+. Water with suspended dirt or organic matter will bind with many herbicides.
1387. Cony, Ann. unknown. First of kind natural herbicide reported.. Sacramento Bee (newspaper).
Richard W. Jones, of UC-Berkeley, reported the use of a natural, self-destructing herbicide capable of killing a wide variety of weeds. It is made from a common soil fungus Gliocladium virens which is artificially charged with nitrogen, thus causing it to produce a compound that is toxic to plant roots for about 2 weeks. The herbicide can kill plant roots as well, but it doesn't hurt plant stems. Thus timing and placement are crucial. The herbicide prevents germination and emergence of weed seedlings, and also produces an antibiotic that protects crop seedlings from rotting.
1891. Erickson, L.C., C.I. Seely, and E.W. Whitman. 1948. Using 2,4-D for selective and non-selective weed control.. ID Extension Bull. 172.
Early discussion of the use of 2,4-D. Various formulations, application rates, methods. Grain yields reduced 5-15% when treated with enough herbicide to kill 90% of common annual weeds.
2424. Hannesson, H.A., R.N. Raynor, and A.S. Crafts. 1945. Herbicidal use of carbon disulfide.. Univ. California Agr. Expt. Sta. Bull. 693.
Temporary soil sterilant (6-8 wk). Studied diffusion and action of carbon disulfide in soils. Particularly effective on deep-rooted perennials. Requires hundreds of pounds per acre for effective treatment. Often a growth response to a following crop, due to S additions.
2862. Hurd-Karrer, A.M.. 1946. Relation of soil reaction to toxicity and persistence of some herbicides in greenhouse plots. USDA Technical Bulletin 911.
Deals with herbicides used prior to 2,4-D, such as sodium chlorate, sodium thiocyanate, ammonium sulfamate, borax. Initially, all herbicides were most toxic in acid soils, and least toxic in alkaline soils, and persisitence was similar. Borax was the most persistent. Nitrogen fertilizer did not reduce chlorate toxicity in a practical manner.
2880. Idaho Agr. Expt. Sta.. 1946. Annual report. Id Agr. Expt. Sta. Bull. #268.
First mention of 2,4-D in the station reports.
2889. Idaho Agr. Expt. Sta.. 1947. Annual report. ID Agr. Expt. Sta. Bull. #269.
Weed response to 2,4-D - perennials; alfalfa by fertilizer experiments - hay yield over 4 T/ac, responded to P,S; wheat yields after 7 yr alfalfa responded to S and ammonium sulfate; yields up to 68 bu/ac. T: weed response to 2,4-D.
3021. Swan, D.G.. 1983. Weed control in winter wheat.. WSU Extension Service, Ext. Bull. #599.
Keep the problem from occurring. Use crop rotation, especially a spring crop, to upset the weed species cycle. Eradicate all new weed species before they spread. Keep weeds from producing seed in the field.
3029. Swan, D.G.. 1972. Weed control in winter wheat in eastern Washington.. Proc. 11th Br. Weed Control Conf., vol.2, p.681.
Bromoxynil, while less effective on some weed species, was the most selective herbicide. Diuron, linuron, and terbutryne frequently reduced yields on soils with less than 1.5% organic matter.
3036. Swan, D.G., M.M. Oveson, and A.P. Appleby. 1974. Chemical and cultural methods for downy brome control and yield of winter wheat.. Agron. J. 49:793-795.