natural-products-in-plant-pest-management

Natural Products from Plants 71artificial and natural infection conditions. The latter is important in light ofthe fact that the use of copper-containing antimicrobials is phasing out inEurope due to recent legislation, while the use of antibiotics, such as streptomycin,is highly opposed.Current status of antimicrobial products from plant extractsExtracts from various plant species appear to have promising potential fortheir application as natural products in the agricultural industry against bothplant pathogenic bacteria and fungi and to be integrated in plant diseasemanagement systems. However, to date, the number of commercially developednatural plant products that emerged from screening programmes isalarmingly low. The natural plant product Milsana ® , extracted from the giantknotweed (Reynoutria sacchalinensis), is probably best known (Daayf et al.,1995). The product has been reported to control powdery mildew, caused bySphaerotheca fuliginea, in the long English cucumber under greenhouse conditions,and also showed broad spectrum activity against powdery mildew oftomato, apple and begonia as well as downy mildew of grapevine and rustof bean (Daayf et al., 1995). It was concluded by Petsikos et al. (2002) thatMilsana ® can substantially contribute to the management of cucumberpowdery mildew in organic or integrated farming systems.A volatile natural product, Carvone, derived from dill and carawayseed, has been developed to inhibit the growth of storage pathogens and tosuppress sprouting of potatoes in the warehouse (Moezelaar et al., 1999). Carvoneis currently marketed as Talent ® in the Netherlands. Additionally,Fungastop and Armorex II, two natural products developed in the USA(Soil Technologies Corp.), are commercially available for the control ofvarious plant diseases in agriculture.Dayan et al. (2009) supplied an excellent summary of new natural antimicrobialproducts that were recently commercialized for use in either conventionalor organic agricultural or both industries. To name a few, these includeBla-S (against rice blast disease in eastern Asia), Kasugamin (against riceblast and other crop diseases in Japan), Mildiomycin (against powderymildews mainly in Japan), Delvolan (against fungal diseases of ornamentals)and Validacin (used for Rhizoctonia spp. control on a variety of crops).All of these products are fermentation secondary products from Actinomycetes,mostly Streptomyces spp., commercialized for use as agriculturalfungicides in Japan, and to a lesser extent in other parts of the world.Several plant essential oils are marketed as fungicides for organic farmers(Dayan et al., 2009). These include E-Rase from jojoba (Simmondsia californica)oil, Sporan from rosemary (Rosemarinus officianalis) oil, Promaxfrom thyme (T. vulgaris) oil, Trilogy from neem (A. indica) oil and GC-3being a mixture of cottonseed (Gossypium hirsutum) oil and garlic (A. sativum)extract. According to Dayan et al. (2009), few scientific papers deal with theseproducts or the actual active components, and their modes of action againstindividual plant pathogens are largely unknown.