Dr. Charles Francis
Date of this Version
Martínez, C. (2018). Canavalia gladiata and Dolichos lablab extracts for sustainable pest biocontrol and plant nutrition improvement in El Salvador. (Master's thesis, University of Nebraska-Lincoln, U.S.A.)
Botanical repellents and pesticides are now being rediscovered as new tools for integrated pest management in order to reduce the use of toxic chemicals in crop production. Canavalia gladiata and Dolichos lablab are two Fabaceae very well adapted to farmlands of El Salvador, effective as living barriers and mostly as cover crops, however, they are not yet very well disseminated. This document describes the potential for using the liquid extracts and the dry flour of raw seeds of those plants for economic benefit and practical convenience for pest management in Salvadorian agriculture under field conditions. Seed extracts were useful when applied to the foliage to repel white flies (Aleyrodidae spp.) and cucumber beetle (Diabrotica spp.), at the dose of 10% v/v; the repellent effect lasted approximately up to 8 days. Thrips, in contrast, were not affected by any dose. The flour produced from the ground seeds was effective for preventing infections of Meloidogyne spp. and Phyllophaga spp., when mixed with soil prior to transplant; the beneficial effect lasted for about one month. Another added value of those flours was the contribution to plant nutrition in the short term, yet applying this treatment must be delayed until after crop germination and emergence because it can cause growth disorder in young seedlings. These leguminous crop seed extracts and flours appear to have promise for commercial application, especially by limited resource farmers.