Weed control North America

The short list of chemicals represents only a small fraction of the inputs applied throughout North America. Lindane, malathion, MCPP, metolachlor, metribuzin, oryzalin, pendimethalin, and pronamide are just a few other of the dozens of formulations for insect and weed control available at any hardware or home maintenance store. All of them are toxic to some degree or another, and question marks hang over many of them as to the risk they may pose for people and the ambient environment. The potential hazards of each of the chemicals described above hints at the range of contemporary hazards associated with lawn care. 

Weed Control Trends and Practices in North America... 

Herbicides have resulted in a great improvement and diversity in weed management techniques among the various crops grown in North America. An example closely correlated with the triazine herbicides is that of row crop production in the Midwest. If we follow the trends of com and soybean production, we see how the management of weed control has evolved in response to economic, cultural, and social influences and needs. Because the State of Illinois... 

Simazine is widely used for preemergence control in field-grown nursery stock in North America. Selective use in container nurseries also has been demonstrated (Ahrens, 1972 Fretz, 1974 Wadsworth, 1975 Bing, 1983). It is less widely used in container-grown nursery production because of potential leaching (Elmore et al., 1976), but is especially effective when applied in the fall or winter to control winter annual weeds in containers. Simazine currently is registered in the United States for 50 species of woody ornamental nursery stock and Christmas trees. Tables 18.1 and 18.2 list selected species of conifers and deciduous ornamental plants, respectively, and their observed tolerance to simazine at rates of 2.2-3.3kg/ha. Information for these tables was obtained from personal observations and the literature, including those references by Ries et al. (1959) Ahrens (1961) Ticknor (1972) and Schubert et al. (1986). 

The herbicide atrazine (2-chloro-4-ethylamino-6-isopropylamino-l,3,5-triazine) is Ihe most heavily used agricultural pesticide in North America. In the United States alone, more than 50 million kg (110 million pounds) are applied annually to more than 25 million ha (62 million acres), primarily to control weeds in com and sorghum. Residues have been detected at phytotoxic concentrations in groundwater, lakes, and streams as a result of runoff from... 

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