Transcript Huiting
Perennial weeds: anaerobic soil disinfection & mechanical methods Hilfred Huiting, Piet Bleeker & Marleen Riemens EWRS workshop Physical & Cultural Weed Control – Samsun, March 2011 Perennial weeds: setting the scene Difficult to control: In organic farming: Species intrinsically are very resilient → exhaust strategy Perennial weed problems take a long breath to control No chemical options Increasing labour cost In conventional farming: Increasing farming scale • Weed problems may stay unnoticed longer • Tendency towards ”easy” solutions may increase problems Herbicide availability Research on perennial weeds Two field experiments, in Wageningen and Lelystad, integrating reasearch on: Weed phenology Chemical weed control strategies Non-chemical weed control strategies Materials & methods: weeds Root pieces planted spring 2009 Cirsium arvense – creeping thistle Rorippa sylvestris – creeping yellowcress Sonchus arvensis – field sowthistle Calystegia sepium – bindweed Equisetum arvense – field horsetail Tussilago farfara – coltsfoot Elymus repens – couch grass Rumex obtusifolius – bitter dock Polygonum amphibium – water smartweed Materials & methods: treatments Mechanical weed control Broadcast blade • Application at 5 cm depth; ”superficial” • Application at 15 cm depth; ”deep” Rod weeder • Mounted behind rigid tine cultivator • Application at c. 6 cm depth Anaerobic soil disinfection, 11 week period Incorporation of weed biomass and covering Incorporation of weed biomass and additional 40 ton/ha fresh grass and covering Materials & methods: treatments Mechanical weed control Broadcast blade • Application at 5 cm depth; ”superficial” • Application at 15 cm depth; ”deep” Rod weeder • Mounted behind rigid tine cultivator • Application at c. 6 cm depth Anaerobic soil disinfection, 11 week period Incorporation of weed biomass and covering Incorporation of weed biomass and additional 40 ton/ha fresh grass and covering Materials & methods: treatment schedule Blade 5 cm 15 April Blade 15 cm X Rod weeder X 20 April X 20 May X 2 June X 15 June X X X 1 July X X X 20 July X X X X X X 28 July 12 August 15 October Disinfection X X X X X Mechanical weed control – blade Sandy soil Marine loam soil Mechanical weed control – rod weeder Marine loam soil Sandy soil Results Sonchus avernsis Results Polygonum amphibium Results Tussilago farfara Results Calystegia sepium Results Cirsium arvense Results Equisetum arvense Results Elymus repens Results Rorippa sylvestris Results Rumex obtusifolius Overview efficacy mechanical weed control Efficacy: Cirsium arvense -: insufficient Calygestra sepium Equestium arvense X: >85% Elymus repens XX: >90% Polygonum amphibium XXX: >95% Rumex obstifolius Rorippa sylvestris XXXX: > 99% Sonchus arvensis Tussilago farfara Rod weeder Knife superficial Knife deep XXXX XXXX XXX XXXX - - XXXX XXXX XXXX XXX - - XXXX XXX XX XXXX X - X - - XXXX XXXX XX XXXX XXX - Anaerobic soil disinfection Without grass With grass Anaerobic soil disinfection: % soil covering Discussion & conclusions Rod weeder very effective after frequent passes Broadcast blade effective as well, if used superficially and frequently Anaerobic soil disinfection may be promissing Results only after one season !!