The Phorbol Ester Fraction from Jatropha curcas Seed Oil: Potential and Limits for Crop Protection against Insect Pests

Abstract

The physic nut shrub, Jatropha curcas (Euphorbiaceae), has been considered as a “miracle tree”, particularly as a source of alternate fuel. Various extracts of the plant have been reported to have insecticidal/acaricidal or molluscicidal/anthelminthic activities on vectors of medical or veterinary interest or on agricultural or non-agricultural pests. Among those extracts, the phorbol ester fraction from seed oil has been reported as a promising candidate for use as a plant-derived protectant of a variety of crops, from a range of pre-harvest and post-harvest insect pests. However, such extracts have not been widely used, despite the “boom” in the development of the crop in the tropics during recent years, and societal concerns about overuse of systemic chemical pesticides. There are many potential explanations to such a lack of use of Jatropha insecticidal extracts. On the one hand, the application of extracts potentially harmful to human health on stored food grain, might not be relevant. The problem of decomposition of phorbol esters and other compounds toxic to crop pests in the field needing further evaluation before such extracts can be widely used, may also be a partial explanation. High variability of phorbol ester content and hence of insecticidal activity among physic nut cultivars/ecotypes may be another. Phytotoxicity to crops may be further limitation. Apparent obstacles to a wider application of such extracts are the costs and problems involved with registration and legal approval. On the other hand, more studies should be conducted on molluscicidal activity on slugs and land snails which are major pests of crops, particularly in conservation agriculture systems. Further evaluation of toxicity to natural enemies of insect pests and studies on other beneficial insects such as pollinators are also needed.

Ecological Interactions Within the Biodiversity of Cultivated Systems

“…However, again unlike neem or pyrethrum, its extracts have rarely been used for crop protection. This is so despite several studies undertaken over the past 30 years having demonstrated its effectiveness on some 40 species of pests and a dozen crops (on the field or during storage) and despite a dramatic increase in its cultivation as agrofuel in the tropics and in spite of societal concerns regarding the excessive use of chemical pesticides (Ratnadass and Wink 2012).…”

“…Several examples illustrate this, including the use of essential oils as alternatives to antibiotics in aquaculture in Madagascar (Sarter et al 2011;Randrianarivelo et al 2009Randrianarivelo et al , 2010 or on terrestrial livestock to repel biting insect (e.g., geranium oil used on cattle in Reunion against Stomoxys calcitrans), the use of Jatropha extracts as an anthelmintic (Ratnadass and Wink 2012) or of the extract of cassava leaf (Manihot esculenta) against Haemonchus contortus, a major helminth parasite of small ruminants (Marie-Magdeleine et al 2010). In each case, it was a matter of identifying alternatives to counter the harmful effects of the massive use of anthelmintics on natural soil macrofauna (see 'Hidden soil biodiversity: what potential for agriculture?…”

Ecological Intensification for Crop Protection

“…This is the case with Jatropha live-hedges planted around market-gardens to keep domestic animals away, or neem wind-breaks planted around orchards, with both also contributing to conservation biological control (Ratnadass and Wink 2012 ).…”

Technical and Economic Evaluation of Phorbol Esters Extraction from Jatropha Curcas Seed Cake using Supercritical Carbon Dioxide

“…The purified PEs could also be converted or transformed chemically into nontoxic compounds with beneficial activities such as the hydrolysis of 12-deoxy-16-hydroxyphorbol that results in the synthesis of 12-deoxyphorbol-13-phenyl acetate, a compound that is considered as a promising adjuvant for antiviral therapy because of its anti-HIV properties (Wender et al, 2008). Some studies had been reported the antifungal and insecticide properties from Jatropha curcas seed cake attributed to the presence of PE , Devappa et al, 2012Ratnadass and Wink, 2012;Saetae and Suntornsuk, 2010).…”