Plant protection from diseases

B. J. J. Lugtenberg, L. A. de Weger, and J. W. Bennett, Microbial stimulation of plant growth and protection from disease. Current Opinion in Biotechnology 2 457 (1991). 

Dr.R.Maag AG (CRD), from 1990 Ciba-Geigy Plant Protection Division (Disease Control), Ueberlandstrasse 138, CH-8600 Duebendorf, Switzerland. Present address J.-P. Obrecht, Dr.R.Maag AG, CH-8157 Dielsdorf, Switzerland. 

Plants, like humans and animals, need adequate water, protection from disease, and certain chemical compounds to grow. Soil fertility where no agriculture occurs is maintained at an even level when the waste products derived from plants are returned to the soil. Human agriculture prevents this from occurring. Fertilizers are materials given to plants to promote growth. Nitrogen, phosphorus, and potassium are the most important elements in fertilizers. 

CTS is widely used in plant protection from the 1990s. Researchers found that CTS can elicit defense to more than 60 diseases on several plants. The potent effect of CTS on plant diseases control is from its antimicrobial and plant innate immunity elicited activity. Though there are many papers focused on CTS and plant protection, there are still many problems that need to be studied. The vital problems to be solved are... 

Selective toxicity is also important in relation to the development of resistance or tolerance to pollutants from two distinct points of view. On the one hand, there is interest among scientists concerned with crop protection and disease control in mechanisms by which crop pests, vectors of disease, plant pathogens, and weeds develop resistance to pesticides. Understanding the mechanism should point to ways of overcoming resistance, for example, other compounds not affected by resistance mechanisms or synergists to inhibit enzymes that provide a resistance mechanism. On the other hand, the development of resistance can be a useful indication of the environmental impact of pollutants. 

The best evidences are studies from preclinical animal models [86, 87, 105], or knockout animals lacking appropriate anti-oxidative pathways [106]. For example, Balb/c mice administered a variety of anti-oxidants in their chow were protected from acetaminophen hepatotoxicity [107]. Rats fed with the anti-oxidant melatonin were protected from cholesterol mediated oxidative liver damage [108]. The best clinical evidence that oxidative stress is a key player in a variety of liver injury diseases is the beneficial application of silymarin in these disease indications [109]. Silymarin is a polyphenolic plant fiavonoid (a mixture of flavonoid isomers such as silibinin, isosilibinin, silidianin and silichristin) derived from Silymarin maria-num that has antioxidative, antilipid peroxidative, antifibrotic and anti-inflammatory effects [109, 110]. 

Protecting plants from diseases Role of pesticides and insecticides... 

Because planls are also susceptible lo cancer and viruses, Lhey have developed their own protective substances, called phytochemicals (from phyton, the Greek term for plant). Evidence from research is accumulating that many phytochemicals also protect humans against cancer and other diseases (Weiss, 1997). 

Cyclodienes are an important group of chlorinated pesticides. The group hep-tachlor includes insecticides such as chlordane, aldrin, dieldrin, endosulfan, and heptachlor and its epoxide. These are used for the control of a variety of plant pests in agriculture and household environments. The entry of cyclodienes to the global market has created easy management for the control of crop pests. They appeared after World War II as tools to protect food crops and control diseases from pests. In fact, humans were protected from malaria, typhus, and loss of food crops by pesticides. 

Protects animals and plants from disease and pests or when human health may be affected. 

The existence of an immune system in mammals, highly effective in protecting against disease after recovery from an initial infection, also has not prevented periodic catastrophic epidemics and epizootics. However, an astute English country doctor, Edward Jenner, noted immunological cross protection against deadly smallpox in English milkmaids who had recovered from mild cowpox. Despite skepticism, ridicule and even hostility of many of his peers, Jenner developed vaccination as one of the safest and most effective mammalian disease preventive measures known. We hope and believe that the same can be accomplished for plants. 

Probably, the most ubiquitous type of resistance is non-host resistance. Plants are constantly in contact with many different microbial organisms, of which only a very restricted number is able to successfully infect a given plant species. This type of resistance protects the plant entirely from infection by most potential pathogens, and is manifested as an inability of the pathogen to cause disease upon contact with any individual of a particular plant species. In such an interaction, the pathogen is considered to be non-... 

Under rain shelters, bush fruits are at least partially protected from various diseases (e.g. grey rot) (see Fig. 3.5). In addition, plants that are covered by a shelter produce fruits with better keeping quality, and the time of picking, as in the case of currants for example, can be postponed to some extent. The disadvantages of rain shelters are the very high installation costs, the relatively high consumption of energy and resources in manufacture, and the adverse effect on the landscape. 

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