Allelopathic potential from cover crops aqueous extract on weeds and maize

Maicon Reginatto,Henrique Von Hertwig Bittencourt,Paulo Cesar Conceição,Lisandro Tomas Da Silva Bonome,Luciano Tormen,Leonardo Khaôe Giovanetti

doi:10.33448/rsd-v9i10.8579

Abstract

Cover crops are used as a strategy to recover degraded soils, improving their physical, chemical and biological characteristics, as well as assisting in the control of weeds through allelochemical compounds released by the shoot degradation process. This work aimed to evaluate the phytotoxicity of the aqueous extract of the cover crops Raphanus sativus L., Avena strigosa (Schreb) and Vicia villosa R. on the germination and initial growth of Zea mays, Amaranthus spinosus L. and Ipomoea grandifolia (Dammer) O'Donnell, as well as to identify and quantify the phenolic compounds present in the extract. Straws from the dried and crushed cover crops were used. The extracts were obtained by mixing 10% R. sativus and A. strigosa, and 12% V. villosa in distilled water (m/v). DIC was used, with four replications, in a 3x4 factorial scheme, with 3 cover crops (R. sativus, A. strigosa and V. villosa) and 4 concentrations (0%, 25%, 50% and 75%). The variables analyzed were: germination, germination speed index (GSI), seedling growth, root protrusion (RP), root protrusion speed index (RPSI) and dry mass of the root and shoot. Higher concentrations of the extracts affected the initial development of maize and weeds. The phenolic compounds identified in greater quantity were benzoic acid, p-coumaric acid, followed by ferulic acid and p-hydroxybenzoic acid. It is suggested that studies of the same nature be carried out in the field, since the interactions between soil microorganisms, climatic conditions can interfere with the results.

Highlights

IntroductionThe seeds of the cover crops plants Vicia villosa R
The use of cover crops is an agricultural practice that consists in the employment of plant species, usually legumes (Fabaceae), grasses (Poaceae) and some species of Cruciferae and compositae, either in rotation or in consortium with the agricultural crops of interest
The seed quality tests of the cover crops, weeds and maize were carried out obtaining moist content through the oven standard method at 105 °C and germination rate through the germination standard test, described in the Rules for Seed Analyses (Brasil 2009)

Summary

Introduction

The seeds of the cover crops plants Vicia villosa R. (spiny amaranth) seeds, Ipomoea grandifolia (Dammer) O'Donnell (morning glory), were collected in June 2017 after reaching physiological maturity, from infested areas in the municipalities of São Miguel do Oeste – SC (26°40'47.1"S 53°31'21.5"W) and Marmeleiro – PR (26°13'28.0"S 53°08'09.6"W), respectively. The Zea mays L. seeds used were conventional hybrid maize cv. The sample seeds of spiny amaranth and morning glory were cleaned with a seed blower to remove impurities and damaged seeds. The seed quality tests of the cover crops, weeds and maize were carried out obtaining moist content through the oven standard method at 105 °C and germination rate through the germination standard test, described in the Rules for Seed Analyses (Brasil 2009)

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