Agriculture Vegetables, Weed

Present studies in warm and temperate region. At present, we are assessing the allelopathic potential of weeds from a tropical region of the country (Uxpanapa, Veracruz), as a complement to the project entitled Recovery of Tropical Rain Forests from INIREB. This information is necessary to permit more efficient agricultural and forest management of the secondary vegetation in the tropics. 

Melander, B. 1998b. Interactions between soil cultivation in darkness, flaming and brush weeding when used for in-row weed control in vegetables. Biological Agriculture and Horticulture 16(1) 1-14. 

Jackson, L.E., Ramirez, J., Yokota, R., Fennimore, S.A., Koike, S.T., Henderson, D.M., Chaney, W.E., Calderon, F.J. and Klonsky, K. 2003. On-farm assessment of organic matter and tillage management on vegetable yield, soil, weeds, pests, and economics in California. Agriculture Ecosystems and Environment 103 443-463. 

The agricultural use of pesticides such as insecticides, herbicides, and fungicides has clearly reduced crop losses due to insects, weeds, and plant diseases in the US and throughout the world. The benefits from agricultural pesticides include improved crop yields, greater availability of fruits, vegetables, and grains, and lower consumer costs (Ecobichon, 1996). 

Krutz, L.J., S.A. Senseman, R.M. Zablotowicz, and M.A. Matocha (2005). Reducing herbicide runoff from agricultural fields with vegetative filter strips A review. Weed Sci., 53 353-367. 

For the 2000 growing season, the National Agricultural Statistics Service (NASS) of the USDA surveyed adoption of individual IPM practices (USDA-NASS, 2001). A summary of results for the major field crops, fruits and nuts, and vegetables is presented in Table 32.5. The adoption of systematic scouting for pests (weeds, insects, or plant diseases) looks very promising. 

Studies were conducted by Burgos and Talbert (1996) at the Main Agricultural Experiment Station in Fayetteville and the Vegetable Substation in Kibler, Arkansas, in 1992 and 1993 on the same plots to evaluate weed suppression by winter cover crops alone or in combination with reduced herbicide rates in no-till sweet com and to evaluate cover crop effects on growth and yield of sweet com. Plots seeded to rye plus hairy vetch, rye, or wheat had at least 50% fewer early season weeds than hairy vetch alone or no cover crop. None of the cover crops reduced population of yellow... 

Uses 2,4-D is a colorless powder with a mild phenylic odor. There are many derivatives of 2,4-D, including esters, amines, and salts. As a systemic herbicide, it is used to control many types of broadleaf weeds. It is used in cultivated agriculture, in pasture and rangeland applications, forest management, home, garden, and to control aquatic vegetation. It may be found in emulsion form, in aqueous solutions (salts), and as a dry compound. 

The first survey to estimate the effects of photochemical air pollution on vegetation was developed in the mid-1950 s (I) for some areas of California. This survey used estimates derived from visible injury and included several major crop types and a single category of weeds, as they responded to certain pollutants. Although the pollutant list was not inclusive, this survey was fairly comprehensive for the crops studied and the California counties included. This survey did not estimate a monetary loss for the area of California covered. However, economic loss predictions have since been based on this early survey following superficial visual estimates of injury in several agricultural areas. These superficial predictions fixed an annual loss of approximately 8 million dollars on the West Coast and 18 million dollars on the East Coast by the early 1960 s for all types of pollutants (2). These estimates were then made countrywide, and yearly losses of between 200 and 500 million dollars have been suggested (3). 

Herbicides are the most important pesticide class in terms of production volume and market value. In agriculture they are used to control weeds. Weeds are unwanted plants, such as grasses, sedges, and broadleaf plants, that compete with the desired crop plants for nutrition, water, and land, thereby reducing the yield. Herbicides also have nonagricultural uses as they help in erasing vegetation on streets, railroad tracks, sports fields, and other public areas. 

Chlorophenoxy herbicides are commonly used for controlling broadleaf weeds in agriculture. They are extensively used for the control of vegetation along highways, maintenance of parks, golf courses, home lawns, and gardens. 

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