Antibiotics as crop protectants

Antibiotics are substances produced by microorganisms that inhibit growth of plant diseases in very dilute concentrations. Cycloheximide, actidione, and streptomycin are the most diffuse antibiotics available for crop protection. Streptomycin is used as dust. 

Remark Biopesticides are used elsewhere, as well. Certain bacteria can be sprayed on strawberries and other fruit crops to protect them against late frosts. Other bacteria, fungi, and yeasts are used to control diseases of stored fruits. Beneficial bacteria, called probiotics, can be fed to humans and animals to relieve the symptoms of diseases and maladies. Probiotics can produce useful biochemicals (such as vitamin K in the human gut), attack harmful viruses and bacteria through natural antibiotics, and crowd out harmful microbes. Competitive exclusion is a powerful weapon that has only begun to be used to advantage. 

Kasugamycin has been developed as a specific and effective antibiotic to control rice blast since 1965. The antibiotic controls the disease when applied at 20 ppm in aqueous solution and shows both protective and curative activity [20]. Kasugamycin has been used to control rice blast on a large scale. In practice, the antibiotic is predominantly used as a dust at 0.3% of the active ingredient. In addition, seed treatment with 2% wettable powder of kasugamycin protects rice plants against blast for one month. The antibiotic exhibits a high crop safety no phytotoxicity has been observed. 

In the 19 th century chemistry was viewed as the central discipline around which physics and biology gravitated. The medical revolution with the synthesis of drugs and antibiotics coupled with the development of chemicals protecting crops and the expansion of organic chemistry in every aspect of life increased the life expectancy from 47 years in 1900 to 75 years in the 1990s and to over 80 years in 2007. 

---