United States citrus crops

Ozone and related oxidants are estimated to be responsible for about 95% of the annual 130 million crop loss caused by air pollutants in the United States. Reports have indicated that ozone can seriously damage important crops such as spinach, beans, petunias, citrus, tobacco, soybeans, and alfalfa, and forest trees such as Eastern white pine and Ponderosa pine. 

Petroleum oils are widely used in the treatment of citrus crops in California. They have proved to be the most efficient insecticide per unit of cost for most of the dominant pests of citrus in this area. In an effort to improve oil sprays from the standpoint of both tree safety and insecticidal effectiveness, the research on oil sprays at the University of California Citrus Experiment Station has been intensified. Part of this new effort has involved close cooperation with other laboratories, particularly with the New York State Agricultural Experiment Station at Geneva. The same petroleum fractions and other hydrocarbon compositions were tested simultaneously against citrus and deciduous fruit pests. This coordinated approach has been mutually advantageous, and it is expected that it will lead to an understanding of the fundamental principles involved in the use of hydrocarbon oils as insecticides in general. 

Estimated diazinon use in the United States was 2.6 million pounds (1.18 million kg) of active ingredient for 1983 (Gianessi 1986) and 10 million pounds (4.5 million kg) of active ingredient for 1985 (EPA 1990b). It was estimated that up to 43% of the diazinon applied in this country in 1982 was for non-agricultural uses, 21% was used on field crops (e.g., peanuts, rice, sugarcane, small grains, and citrus),... 

Although simazine was the first triazine to be developed and marketed in corn as well as other crops, the more versatile atrazine quickly became the standard herbicide in corn. Simazine, however, has remained very valuable and is important on forage crops, ornamentals, turf, and several other vegetable, fruit and nut crops, including almond, apple, artichoke, avocado, berries, cherry, citrus, grape, hazelnut, peach, and walnut. There also remains a strong demand for simazine use in corn in some areas based on specific weed pressure. Simazine is manufactured and sold by several companies today in more than 25 countries around the world, with Brazil, the United States, Australia, and Japan ranked as the top four. 

Uses Chlordane is a viscous, amber-colored liquid. Technical-grade chlordane is a mixture of many structurally related compounds including trans-chlordane, cis-chlordane, chlordane, heptachlor, and /ran.v-nonachlor.14,15 Chlordane was used as a broad-spectrum pesticide in the United States from 1948 to 1988. Its uses included termite control in homes and pest control on agricultural crops (e.g., com, citrus, home lawns, gardens, turf, ornamental plants). 

Over 90 percent of the potassium sulfate produced in the United States is used as a fertilizer. It provides plants with two essential elements potassium and sulfur. It finds its greatest use on crops that are sensitive to the chloride ion (C1-) present in most conventional agricultural fertilizers. Those crops include coffee, tea, tobacco, citrus fruits, grapes, and potatoes. However, its use is somewhat limited because it is twice as expensive as fertilizers that contain potassium chloride. 

Among the hexachlorooctahydronaphthalene type compounds, aldrin [309-00-2] was one of the earliest pesticides. It was first synthesized in the United States in 1948. It was produced by Diels-Alder reaction from acetylene and hexachlorocyclopenta-diene. Aldrin readily converts into dieldrin [60- 57-1] on exposure to sunlight or bac-terias. Both aldrin and dieldrin were widely used from 1950 to 1970 for protecting com and cotton crops. They were also used to protect citrus plants and combat soil pests and locust and in the preservation of timber. Because of their high toxicity and hazard to human health, the production of these pesticides ceased in the United States in 1974. After 1974, the uses of these pesticides were limited to control termites. All uses of these... 

Fig. F-72 shows that oranges, grapes, apples, and grapefruits are the leading fruit crops in the United States. The citrus fruits require a subtropical climate. Hence, their production is limited mainly to California, Texas, and Florida. The great growth of the citrus industry after World War II was due in large part to advances in the technology for producing frozen juices from these fruits.

This citrus species is by far the leading fruit crop of the United States, and it is the second leading one of the world. (Grapes are first, and bananas, watermelons, and plantains follow in that order.)... 

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