Plants as natural sources of nematicides

Plant parasitic nematodes can cause serious damages to numerous economically important agricultural crops worldwide. Control of these pests is based on pesticides and on the use of resistant cultivars. Although chemicals are effective in the plant parasitic nematode control, the recent European legislation has deeply revised and restricted their use on agricultural crops focusing the attention on environmental safety and human and animal health. Moreover, resistant cultivars are available only for a limited number of crops and plant parasitic nematode species. During the last decade research on low environmental impact alternatives to nematicides has received a strong impulse and a wide range of options including agronomic strategies, physical methods, bio-pesticides, and biocidal plants have been considered. Focusing on plants, derived natural products known as botanic pesticides can represent useful tools to minimize soil nematode population density under the tolerance limits of the different crops to specific phytoparasitic nematodes. These botanic pesticides are generally non-persistent in field conditions as they are readily transformed by light, oxygen and microorganisms into non-toxic products without residues in the environment. Many botanic pesticides derived from wild and cultivated plants have been shown to possess nematicidal properties against several plant-parasitic nematodes. The aim of this review is to report the effects of botanic pesticides derived from various wild, cultivated and medicinal plants, including essential oils, root and tissues extracts, on plant parasitic nematodes in the view of sustainable agriculture.