Allelopathic effects of Ipomoea cairica (L.) Sweet on crop weeds

Leandro Kenji Takao,Maria Inês Salgueiro Lima,Jose Pedro Nepomuceno Ribeiro

doi:10.1590/s0102-33062011000400012

Leandro Kenji Takao, Maria Inês Salgueiro Lima + Show 1 more

Open Access

https://doi.org/10.1590/s0102-33062011000400012

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Abstract

Identification of species with allelopathic potential has been a target of researches aiming to use them to control crop weeds. Ipomoea cairica is considered a weed with allelopathic potential, which has already been reported. The goal of this study was to evaluate the allelopathic properties of leaf extracts from Ipomoea cairica on the germination and early development of four of the worst crop weeds in Brazil: Bidens pilosa L., Echinochloa crus-galli (L.) Beauv., Euphorbia heterophylla L. and Ipomoea grandifolia (Dammer) O´Donel. We tested the effects of leaf extracts, in four concentrations, on the germination and early development of these species. The extracts negatively affected the germination, early development and the morphology of all target species, and the phytotoxic effect was higher as the concentration of the extracts increased. The influence of the I. cairica extracts on germination, in addition to their effects on seedling development, made them more effective.

Highlights

Studies about the allelopathic process have recently focused on its application in agriculture, with the goal of using allelochemicals as herbicides to develop more sustainable practices (Chon et al 2003)
Allelochemicals and plant extracts cannot provide the same level of weed control when compared to synthetic herbicides, but they can be worthwhile when only a small quantity of herbicide can be used (Khanh et al 2006)
The aim of this study was to evaluate the allelopathic activity of aqueous leaf extracts, made from Ipomoea cairica, on the germination and early development of four crop weeds: B. pilosa, E. crus-galli, E. heterophylla and I. grandifolia

Summary

Introduction

Studies about the allelopathic process have recently focused on its application in agriculture, with the goal of using allelochemicals as herbicides to develop more sustainable practices (Chon et al 2003). Annual global crop losses because of weed species amount to around 95 billion dollars in food production (FAO 2009), and weeds are among the main components of the agroecosystem that interfere in crop production (Kuva et al 2008). They compete for resources, reducing production, and can deposit a high quantity of seeds in the soil, perpetuating the problem during future plantings (Vyvyan 2002). Bidens pilosa L. (hairy beggarticks), Echinochloa crus-galli (L.) Beauv. (barnyardgrass), Euphorbia heterophylla L. (wild poinsettia) and Ipomoea grandifolia (Dammer) ODonel (morning glory) are among the worst

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