Herbicidal potential of Lantana camara l. on Ludwigia spp in paddy soil

Sudheera Mw Ranwala,L R Attigala,Shwetha De Silva

doi:10.4038/tare.v17i1.5293

Abstract

This study assessed herbicidal potential of Lantana ( Lantana camara L. ), on two commonly found paddy field weeds; Ludwigia decurrens Walt. and Ludwigia hyssopifolia (G. Don) Exell. Methodology involved a laboratory bioassay using 1:5 w/v and 1:10 w/v aqueous Lantana dried leaf extracts to assess germination, cotyledon expan-sion, root and shoot development of udwigia spp. Green house experiments included paddy soil amendments us-ing 1g, 2g, 4g dried Lantana leaf residues in 85g soil and 30g, 60g, 120g residues in 2.5 kg paddy soil respectively to test seedling establishment and growth of Ludwigia spp. Toxicity of Lantana on rice ( Oryza sativa ) was tested by growing rice cv. ‘BG 353’ with L. decurrens in Lantana amended paddy soil. Toxic effects of Lantana on natu-rally occurring micro-biota were also assessed by diffusion method using 1.5 w/v Lantana dried leaf extracts on pure cultures of fungi and bacteria isolated from paddy soil. Results indicated that 1:5 w/v was the strongest ex-tract to suppress root and shoot development of seedlings of both weeds. An amount of 4g Lantana leaf residue in 85g paddy soil suppressed germination and seedling establishment of L. hyssopifolia while higher quantities such as 120g of dried Lantana leaf residues in 2.5 paddy soil was required to suppress growth of L. decurrens. No potential harmful effects of Lantana were observed on growth of rice seedlings and microbiota of paddy soil. Higher quantities such as 120g in 2.5 paddy soil were required to suppress growth of L. decurrens . Tropical Agricultural Research and Extension 17(1): 2014: page 10-18

Highlights

Allelochemicals are partly responsible for the impressive success of alien invaders in nonnative environments, considered as ‘chemical weapons’ (Hierro and Callaway, 2003, Kim and Lee, 2011, Ni et al 2012)
Germination and seedling development of Ludwigia spp exposed to Lantana leaf extracts According to preliminary laboratory trials, weights of 200g and 100g of air dried mature Lantana leaves each were soaked in 1000 ml distilled water at 10oC for 7 days and 1:5 (w/v) and 1:10 (w/v) aqueous filterates were obtained
For isolation of naturally occurring fungi and bacteria, a dilution series of paddy soil suspensions was prepared and 0.1 mL aliquots of 10-1, 10-2, 10-3, 10-4 and 10-5 dilutions were introduced separately to sterile Potato Dextrose Agar (PDA) and Nutrient agar (NA) media supplemented with Tetracyclin (3μL/mL) and Chloramphenicol (1μL/mL) respectively

Summary

Introduction

Allelochemicals are partly responsible for the impressive success of alien invaders in nonnative environments, considered as ‘chemical weapons’ (Hierro and Callaway, 2003, Kim and Lee, 2011, Ni et al 2012). The common Lantana, Lantana camara L., (family: Verbenaceae), listed among the world’s hundred worst invasive alien species (IUCN, 2001) is reported to cause substantial ecological and economic losses to agriculture and biodiversity in many countries (Holm et al 1979, Swarbrick et al 1998, Gooden et al 2009). It contains mono, tri and sesquiterpenes including Lantadene A and B, iridoid and phenyl ethanoid glycosides, flavonoids as allelochemicals (Ghisalberti, 2000) that have shown promising toxic effects on many plant species such as Morrenia odorata Lindl. It has been a common indigenous practice to use of Lantana camara leaf residues (either alone or together with other plant debris) in traditional farming systems in India (CSIR 1966), Kenya (WAC 1995, Roothaert and Franzel, 2001) and Sri Lanka (Ranganath 1993)

Methods

Results

Conclusion