EWRS Joint Workshop. 4-8 September 2011. Huesca, Spain Paper mulch controls purple nutsedge (Cyperus rotundus L.) in processing tomato A. Cirujeda1, J. Aibar2, C. Zaragoza1 1Unidad de Sanidad Vegetal, Centro de Investigación y Tecnología Agroalimentaria (CITA), Zaragoza; 2Universidad de Zaragoza. Escuela Politécnica Superior Huesca Huesca, September 7th, 2011

Cyperus rotundus L. is considered one of the world’s worst weed.

Despite its low size, this species can cause a reduction of up to 28% in the development of tomato (Morales-Payan et al., 2003).

CYCLE OF CYPERUS ROTUNDUS L. in the North of Spain (continental area) SHORT DAY 9h LONG DAY 12h LIGHT Tª LIGHT Tª LIGHT Tª Tª>20ºC Tª<5ºC Tª>15ºC non- viable seeds 21A 21J 21S 21D 21A SPRING SUMMER AUTUMN WINTER CYCLE OF CYPERUS ROTUNDUS L. in the North of Spain (continental area)

Cyperus rotundus infestation in a commercial farm without mulch.

IX Congreso SEAE: Calidad y Seguridad Alimentaria Plastic mulch with black polyethylene (PE) is generally used in extensive horticultural crops in north-eastern Spain, like in tomato.

Objectives In this work we present the effect of some types of paper used in tomato crop infested with C. rotundus during five years.

Material and methods Trial Year Material Company Colour Weight (gm2)   Material and methods Table 1. Description of the treatments. Trial Year Material Company Colour Weight (gm2) All 2005-10 Untreated control - PE Solplast Black 16.4 Mater-Bi1 Novamont 22.3 Aula Dei 2005, 06 Saikraft 2002, 3 Saica Brown 200 Aula Dei, S. Bruno 2007, 08 Saikraft 1402, 3 140 S. Bruno 2008, 09 Mimgreen2 Mimcord 90 2009, 10 Karpan Liner2 Smurfit-Kappa 120 MG2 50 1Biodegradable plastic 2Paper 3Paper coated on one side with an estiren-acrylate copolymer at 150 g/t.

Saikraft Mimcord MG Karpan Liner

Results

Results Figure 1. Cyperus rotundus density 42 days after transplantation.

Results

Results Paper mulch does not prevent Cyperus emergence but as far as it stands the physical pressure and does not break, the plants are not able to reach the light, develop chlorotic leaves, do not flower and die.

Results

Results

Results Drawbacks: If rainfall is frequent, the paper becomes soft and do not dry and the control effect on Cyperus is not reached (Méndez et al., 2006 Northern Spain). This can also happen if the irrigation emitters are placed upwards and the paper is continously wet. Another unconvenient of paper mulch is that in clay soils the degradation of the underground part of the paper mulch may be quite fast and the paper breaks down in the contact line of the mulch with the soil surface allowing the wind to damage it.

Results

Results Tomato yield at the paper mulch treatments was very similar to that obtained in the PE all 5 years of experiments.

Economic aspects Mulching type €/kg* g/m2 €/ha** % Coments Black PE 15 µ 1.85 16.4 202 100 Add aprox.150 € removal cost. Saikraft 125 recycled Paper Saikraft 140 recycled Paper 0.47 0.46 125 140 391 429 193 212 Shorter rolls for same weight MaterBi (biodegradable plastic)15µ 4.75 22.3 706 350 - Biofilm (biodegradable plastic) 17µ 5.8 21 818 404 Black Paper Mimcord 135µ 1.5 90.3 903 446 Good installation. Shorter rolls for same weight *It does not include installation. Prices in Spain, 2010 **2/3 field area covered (1,50m between rows, 1,20m mulch width)

Conclusions Paper mulch is an efficient weed control method including Cyperus spp. unless the mulch is not under continous moisture conditions. Another advantage is the complete degradation of the paper after burial. The main constraints compared to PE is the price (nowadays), the slower installation and the heavier weight of the rolls.

EWRS Joint Workshop. 4-8 September 2011. Huesca, Spain Thanks for your attention!