RESULTS OF METHYL BROMIDE ALTERNATIVES ON TOMATOES CROP IN ROMANIA - PDF document

RESULTS OF METHYL BROMIDE ALTERNATIVES ON TOMATOES CROP IN ROMANIA M. Bogoescu* ,ICDIMPH – HORTING, Bucharest, Romania, A. Minuto, AGROINNOVA – Torino,Italy, A.Amadio, UNIDO Vienna – Multilateral Environment Agreements , Diana Bogoescu, BRM Bucharest In Romania the tomatoes represent the most important crops grown under protection, generally adopting a continuous monoculture. Since crop rotation is rarely adopted, the reduction of yield, both in quantity and quality, progressively affects the crops, thus making necessary the adoption of soil disinfestations practices. Investigations in Horting Institut showed that after 4 years of continuous tomato monoculture a yield reduction up to 48% occurred. Since the adhesion to the Montreal Protocol, Romania government decided to phase out methyl bromide use beginning with 2005. This summary are reported the results obtained in the first cycle 2006 on tomatoes cultivated in demonstration trials for testing alternatives to methyl bromide to control corky root, root knot induced by nematodes and weeds, in Horting Institut (Bucharest) and Leader International (Constanta). The efficacy of the chemical fumigants Metham Sodium(100ml/sqm) , Dazomet (60g/sqm) and 1,3 D + chloropicrine (45g/sqm) were tested and compared to that of methyl bromide(75g/sqm),(standard control). The efficiency of soil disinfestations was assessed by measuring weed density (number of weeds/m 2 , fresh weed weight g/m 2 ), severity of corky root induced by Pyrenochaeta lycopersici and severity of root galls induced by nematodes [root index (0-5)] and the total marketable yield. The incidence of P. lycopersici and the presence of galls induced by nematodes were visually assessed at the end of the trials on 15% of the plants harvested from the middle of the plots. The treatments for soil disinfestations made in springtime, in greenhouses no heating (table 1), when the temperature in soil at 15 cm depth was over 15C.Metham sodium, 1.3 dichloropropen+chloropicrin was applied throw drip- irrigation system, using Venturi pomp. Before applied 1.3 dichloropropen+chloropicrin, the soil irrigated 5 days with 200cm\ha water ; with one day before to make the treatment the irrigation stopped. Dazomet powder was applied by spread on a very good prepared soil with a 50% field capacity and it was immediately incorporated so that water to be found at 20 cm depth. After products was applied the soil was covered with plastic; pause time was of 21 days for soil temperature higher than 15 C at the 15 cm depth, for Metham Sodium and Dazomet; 28 days for 1.3 dichlorpropen+chloropicrin (10 days covered with plastic and 18 days uncovered soil) and 14 days for Methyl Bromide.The experimental variants were organized with Abelus F1 (Tomatoes type); one variant has 300sqm, with 3 repetitions (3 x 100sqm). 126-1

In 2006 year due to climatic conditions, most no heating greenhouses adopted a technology with one long cycle for tomato crops.The results give emphasize to a reduction in the number of weeds(table 2) where the soil disinfection was carried out by 1.3 dichloropropen+chloropicrin and a good nematocide effect for 1.3 dichloropropen + chloropicrin and Metham Sodium. In the both location, it’s obvious that the yield for the 1.3D + chloropicrin and Metham Sodium variants is bigger then the Dazomet variant. For the both variants, the yield is bigger because of the soil disinfection alternative has a positive effect on plant’s production (figure 1). The good effect of soil disinfection turned up because of the reducing weed number, bigger healthy plants rank respectively, who induce better quality and much more fruits. The results obtained showed that the soil disinfestations efficiency with 1.3 Dichloropropen +Chloropicrin was similar to that obtained with Methyl Bromide (table 3,4).The recorded results in soil disinfection using 1.3 Dichloropropen +Chloropicrin and Metham Sodium showed a superior rise compared to Dazomet. This is because alternatives 1.3 Dichloropropen+Chloropicrin have a total eradication effect in pests(table 3), pathogens and weeds, while Metham Sodium has a better efficacy in pest, pathogens eradication and only some weeds as secondary effect. Dazomet treatment has a preventive, eradication efficacy only for nematodes and soil pests, while the secondary herbicide effect is very low. From commercial point of view Metham Sodium (Nemasol) can be bought for 2,73 Euro/liter (supplier Sumittagro Romania, the representative of Taminco) and the Dazomet powder from Borzesti factory Romania for 3,06 Euro/kg. The Metador (Metham Sodium) product was registration this year by ForDor Chemicals Ltd. from Israel and Agrocellone NE was registration by Agroquimicos de Levante,from Spain. For the moment don’t exist the concrete proposal cost for Agrocellone NE and Metador. The recorded results of the demonstrative plots in 2006, emphasize suitable soil disinfection for the Romanian climate, by the following Methyl Bromide chemicals alternatives: - Metham Sodium ( Nemasol , Metador) - Dazomet - 1.3 Dichloropropen+Chloropicrin ( Agrocellone NE) Due of EU environmental policy on the medium or long term the 1.3 Dichloropropen + Chloropicrin utilization in European Country is uncertain. 126-2

Table 1. Relevant dates concerning trials organize Site Metham Dazomet 1.3D+ Methyl Transplant End of the Sodium chloropicrin Bromide trial Horting 03.14.2006 03.14.2006 03.11.2006 03.14.2006 07.28.2007 03.14.2006 Leader 03.14.2006 03.14.2006 03.09.2006 11.04.2006 07.25.2007 03.11.2006 Table 2.The effects of soil disinfection treatments on weeds* Treatment Horting Leader nr weeds/ kg weeds/ nr weeds/ kg weeds Determination sqm sqm sqm sqm Metham Sodium 98 b 0.302 n 87 b 0.123 n Dazomet 135 c 0.369 n 123 c 0.262 p 1.3D+chloropicrin 34 a 0,088 m 42 a 0,057 m Methyl Bromide 21 a 0.064 m 23 a 0.044 m *In a group of letters (a-c) for nr. weeds and (m-p) for kg weeds the values noted with some letter do not present significant difference after the Duncan test for p =5% Table 3. Frequency (%) of Pyrenochaeta lycopersici (corky root) at tomato crop* Site Metham Dazomet 1.3D+chloropicrin Methyl Sodium Bromide Horting 2,4 a 2,1 a 2,1 a 1,8 a Leader 3,3 a 3,5 a 3,3 a 2,3 a *In a group of letters values noted with some letter do not present significant difference after the Duncan test for p =5% 126-3

Table 4. Effect of soil disinfestations on average of percentage and on root index of infested plants with nematodes assessed on all plants collapsed and still living at the end of the trial* Site Metham Dazomet 1.3D+chloropicrin Methyl Sodium Bromide Horting 1,5 b 1,7 b 0,4 a 0,5 a Leader 1,6 b 1,8 b 0,8 a 0,7 a *In a group of letters values noted with some letter do not present significant difference after the Duncan test for p =5% Figure1.The effects of soil disinfestations on commercial yield (t/ha) 118 114 120 98 96 91 100 84 82 80 71 Metham Sodium Dazomet 60 1.3D+chlopicrin Methyl Bromide 40 20 0 Horting Leader 126-4