Diseases, plant

Economic Market. The spice trade is controlled by many direct elements and responds slowly to supply and demand fluctuations. Resupply depends on growth to plant maturity, which for certain items, such as black pepper or nutmeg, can be several years. The raw material is directly affected by climate, adverse weather conditions, and control of plant diseases and insect and animal pests. Limited agricultural scientific advances are appHed to the cultivation of the botanicals, and there are many grades of product and degrees of quahty caused by different growing or processing conditions, sometimes by unknown factors as well. 

Sulfur and its compounds are among the oldest and most widely used pesticides. Elemental sulfur is especially effective as a dust for the control of mites attacking citms, cotton, and field crops and as a protectant against chiggers, Trombicula spp., attacking humans. Sulfur also is a valuable fungicidal diluent for other dust insecticides and is used in wettable form as a spray mixture. Time sulfur has been a standard dormant spray for the control of the San Jose Quadraspidiotuspemiciosus and for other scales and various plant diseases. Time sulfur is a water-soluble mixture of calcium pentasulfide,... 

The fungicides are among the chemicals of wide use as plant diseases control agents in intensive agriculture. At the same time these pesticides could have toxic effects, when accumulated in man and animals. Because of general society concern about fungicides use, they should be monitored in waters, soils and crops. 

By far the greatest emphasis in the research and application of microbial antibiotics has been concerned with animal and human health. Despite the extent of the problems relating to plant disease, the practical use of antimicrobial antibiotics in plant agriculture has been limited to a few crops and compounds Only streptomycin and actidione (XI) at present enjoy commercial importance. This may be due in part to the wider applicability of the less expensive synthetic fungicides and in part to the difficulty of arousing much public sympathy for a sick plant. 

Cooper, R.M. 1984. In (Woods and Jillis, eds.) Plant Diseases Infection, Damage and Loss. Blackwell, Oxford, pgs. 13-27. 

A. Rovira, M. Ryder and A, Harris, Biological control of root diseases with p.seu-domonads. Biological Control of Plant Diseases, (E. S. Tjamos, ed.). Plenum Press, New York. 1992, p. 175. 

S. E. Lindow, Methods of preventing frost injury caused by epiphytic ice-nucle-ation-active bacteria. Plant Disease March ill (1983). 

Initial studies examining the function of siderophores in the rhizosphere have focused on practical problems related to agricultural biotechnology. Early research suggested the involvement of siderophores in plant disease suppression by certain root-colonizing pseudomonads (2). Since then, it has become apparent that siderophore-mediated interactions are only part of the story of how microor-... 

Alkylenebis(dithiocarbamates) compounds, known also as ethylenebisdithiocarba-mates (EBDCs), are nonsystemic, low-toxicity pesticides with strong and broad fungicide activity on plant diseases. Developed by Rohm and Haas and E. I. du Pont de Nemours, they are used to protect vegetables and fruit crops. 

Proper understanding of allelopathic crop and weed plants including their growth stages at which toxin production occurs and characterization of allelopathic agents frcm these plants provide new avenues for developing technologies in weed control, crop efficiency, pest control and plant diseases. 

United States has a total value of about 15,000,000. In 1948, 35,000,000 pounds were produced of one insecticide alone—DDT (9). There are about 25,000 plant diseases in the United States, including 10,000 of economic importance, and these cost the nation about 4,000,000,000 a year. The annual wholesale value of all agricultural chemicals in the United States is about 185,000,000. The Bureau of Chemistry of the State Department of Agriculture in California reported during the fiscal year 1946-47 the registration of 7717 economic poisons. 

The soil and plants employed on the cover are critical to success. A mixture of grasses native to the area is preferred to provide effective water removal from the cover in all years in spite of temporary changes in local conditions. Native grasses have already proven their ability to withstand local climate variations, insects, plant disease, periodic fire, and other factors. A mixture of native grasses assures an active vegetative cover during years when insects, plant disease, or other factors reduce the vigor of one or more species.11-38... 

Staskawicz BJ, Ausubel FM, Baker BJ, Ellis JG, Jones JD 1995 Molecular genetics of plant disease resistance. Science 268 661—667... 

Bacterial plant pathogens are usually identified by microscopic observation and comparison of the symptoms on the plant with published descriptions and photographs, but various rapid serological and molecular methods are now being developed for plant disease diagnosis.16,17... 

Doupnik, B., Jr (1993) Soybean production and disease estimate for north central United States from 1989 to 1991. Plant Disease 77, 1170-1171. 

Kolattukudy PE, Crawford MS (1987) The role of polymer degrading enzymes in fungal pathogenesis. In Nishumura S, Vance CP, Doke N (eds) Molecdar determinants of plant diseases. Springer, Berlin Heidelberg New York, p 75... 

Zadoks, J C and Schein, R D (1979) Epidemiology and Plant Disease Management, Oxford University Press, New York. 

Van Bruggen A H C (1995), Plant disease severity in high-input compared to reduced-input and organic farming systems , Plant Dis, 79, 976-984. 

In many cases, the incorporation of organic matter in the soil may be a beneficial alternative to chemicals for plant disease control. Lor example, Viana et al. (2000) reported that matured cattle manure and sugarcane husks are efficient alternatives for control of bean damping-off (Sclerotinia sclerotiorum). Larmyard manure applied at 5 t/ha once every three years reduced dry root rot (Macrophominaphaseolina) to 32% in groundnut (Arachis... 

Adams, P. B. (1990). The potential of mycoparasites for biological control of plant diseases , Annual Review of Phytopathology, 28, 59-72. 

Curl, E.A. (1988). The role of soil microfauna in plant-disease suppression , Critical Review of Plant Science, 7, 175-196. 

Feld, S.J., Menge, J. A. and Stolzy, L.H. (1990). Influence of drip and furrow irrigation on Phytophthora root rot of citrus under field and greenhouse conditions , Plant Disease, 74, 21-27. 

Koike, S., Gaskell, M., Fouche, C., Smith, R. and J. Mitchell (2000). Plant Disease Management for Organic Crops, University of California, Division of Agriculture and Natural Resources. Publication 7252, http //anrcatalog.ucdavis.edu. 

Sullivan, P. (2001). Sustainable Management of Soil-borne Plant Diseases. ATTRA, USDA s Rural Business Cooperative Service, www.attra.org attra-pub/soilbome.html... 

Some strains have been used as a medicinal product to treat dysentery and other intestinal problems, and as a pesticide to control plant diseases and fungal pathogens. 

United States Department of Agriculture. Office of Pest Management National Plant Disease Recovery System. "Recovery Plan for Huanglongbing (HLB) or Citrus Greening Caused by Candidatus Liberibacter africanus, L. asiaticus, and L. americanus." September 20, 2006. 

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