Preliminary results on application of ammonia and organic amendants for soil disinfestation in northern italy

PRELIMINARY RESULTS ON APPLICATION OF AMMONIA AND
ORGANIC AMENDMENTS FOR SOIL DISINFESTATION IN
NORTHERN ITALY
A. MINUTO*, G. MINUTO**, G. GILARDI*, A. GARIBALDI* and M.L.
* Di.Va.P.R.A. - Patologia Vegetale, Università di Torino, Via L. Da Vinci n° 44, 10095 Grugliasco (To) - **Centro Regionale di Sperimentazione ed Assistenza Agricola, C.C.I.A.A. Savona, Regione Rollo 98, 17031 Albenga Methylisiothiocyamate generators (metham sodium - MS, dazomet - DZ) andsoil solarization (SS), applied alone or combined with several soilamendments releasing ammonia (Gamliel and Stapleton, 1993 and 1995;Cebolla et al. 1999, Di Primo and Cartia, 1998) have been widely investigatedamong available alternatives to methyl bromide (MB). This paper shortlydescribes the results of two experimental trials carried out at Albenga (Liguria– Northern Italy). The trials were carried out under greenhouse conditions insoil artificially infested with Fusarium oxysporum f. sp. basilici andRhizoctonia solani. Chicken manure (Agrifumax Casalserugo -Pd- : N organic2,5 %; C organic 25 % - pellet) and (NH4)2SO4 (soil fertiliser 21% of N -granulated) was distributed with soil rototilling. The NH3 (availableformulation 5% of NH3) was applied by soil drenching with the sameequipment employed for MS application. Soil was mulched with polyethylene(PE, 50 µm thick) or gas impermeable (VIF, 35 µm thick) films. During the 1st trial all different combinations among MS, chicken manure, (NH4)2SO4 andSS reduced the incidence of F. basilici on basil and R.solani on bean (table 2).
For bean on the 2nd crop, better results were obtained by combining MS (191g/m2), chicken manure (50 g/m2) and SS (14 days) or MS (191 g /m2), NH3(100 g/m2) and SS (14 days). All treatments had similar efficacy againstPyrenochaeta lycopersici on tomato (table 3). During the 2nd , trial the 1st cropof bean (table 5) showed the good efficacy of BM applied at 30 g/m2 underVIF; similar results were obtained with DZ alone or in combination withchicken manure (1 or 3 kg/m2). In spite of the low disease pressure, DZ wasmore effective when combined with 1 kg/m2 of manure. The total biomassproduced by plants grown on soil treated with DZ (50 g/m2) and manure (3Kg/m2) was higher in comparison to the others treatments. On basil, alltreatments gave interesting results. However chlorosis and reduced growthwere observed on basil and bean grown in the plots treated with chickenmanure. In conclusion chicken manure, NH3, [NH4]2SO4 can be effectivelycombined with chemicals (DZ, MS) and SS for soil disinfestation. In NorthernItaly, where SS can be only partially effective, the above describedcombinations not always improve efficacy of DZ or MS. According to manyauthors, the application of soil amendments, among witch chicken manure,seem to be an efficient method to improve SS (Gamliel and Stapleton 1993;Gamliel and Stapleton 1995). Other researchers (Cebolla et al., 1999)described phytotoxicity. Our results only partially encourage the application of soil amendments as chicken manure, (NH4)2SO4 or NH3 , due todevelopment of phytotoxicity and to the increased labour required.
Work carried with a contribution of the Italian Ministry for the Environment,Rome.
References
DI PRIMO P., CARTIA G. ,1998. La "biofumigazione" del terreno per il
contenimento di Sclerotium cepivorum e Sclerotium rolfsii. Atti Giornate
Fitopatologiche 1998, 2, 677-680.
CEBOLLA V., BARTUAL R., FERRER A., GINER A., 1999. Alternatives to
the conventional use of methyl bromide on strawberry crop. In: Proc.XIVth
Int. Plant Protection Congress. Jerusalem 1, 95.
GAMLIEL A., STAPLETON J.J., 1993. Effect of chicken compost or
ammonium phosphate and solarization on pathogen control, rhizosphere
microrganisms, and lettuce growth. Plant Disease, 77, 886-891.
GAMLIEL A., STAPLETON J.J., 1995. Improved soil disinfestation by
biotoxic volatile compounds generated from solarized organic-amended soil.
Acta Horticulturae, 382: 129-137.
Table 1 – Experimental trial conditions.
° Bean cv "Canellino" (S.A.I.S. - Cesena) 50 seeds/m2; °° basil cv "Genovese Gigante" (S.A.I.S. -Cesena) 4 g seeds/m2; °°° Tomato cv "Marmande marinda" 2 plants/m2, cv "Cuore di bue" 2 plants/m2.
Table 2 - Effect of soil treatments against R.solani on bean and F.basilici on basil (1st trial;basil 1st sowing: control on 14/09/98; 2nd sowing: control on 18/11/99; basil: control on21/10/98).
Treatment * Means of the same column followed by the same letter do not statistically differ followingDuncan's Multiple Range Test (P =0.05).
Table 4 - Effect of soil treatments against Pyrenochaeta lycopersici on tomato (1st trial:control on 25/05/99).
Treatment Table 5 - Effect of soil treatments on the incidence of R.solani and on biomass production onbean and on the incidence of F.basilici on basil (2nd trial; bean: control on 22/09/98; basil:control on 20/10/98).
Treatment

Source: http://www.mbao.org/altmet00/26minuto.pdf