Author
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Chellemi, Daniel |
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Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/1/2006 Publication Date: 8/5/2006 Citation: Chellemi, D.O. 2007. Effect of urban plant debris and soil management practices on plant parasitic nematodes and soilborne diseases of pepper. Crop Protection. Interpretive Summary: Soil fumigation with methyl bromide is considered essential for the production of fresh market bell pepper in the southeastern U.S. However, methyl bromide is classified as a Class I Stratospheric Ozone Depleting Substance and its use in the United States is being phased out. This study examined the effect of alternative soil management practices on the incidence of plant disease and density of plant parasitic nematodes in commercial farms planted to bell pepper (Capsicum annuum). Replicated field plots were established on a diversified organic vegetable farm that had been under certification for 5 years and on a conventional pepper farm that had been fumigated with methyl bromide and cropped annually to bell pepper for 25 years. Soil management practices included the incorporation of 67 t ha-1 of urban plant debris (UPD) prior to planting, minimum tillage into the stubble remaining from a cover crop of sunn hemp (Crotalaria juncea) or iron-clay pea (Vigna unguiculata), cultivation with raised polyethylene-mulched beds, soil solarization, and. Soil fumigation with methyl bromide: chloropicrin was also evaluated at the conventional farm site. Addition of UPD significantly reduced the incidence of Pythium root rot in 2000 at the organic site and Phytophthora blight in 1999 at the conventional site when compared to treatments without UPD. Soil solarization and soil fumigation significantly reduced Phytophthora blight in 1999 at the conventional site when compared to pepper produced in untreated soil covered by polyethylene plastic mulch. Addition of UPD significantly reduced the density of plant parasitic nematodes at the Organic site in 2000 and the conventional site in 1999 when compared to treatments without UPD. Soil solarization significantly reduced densities of plant parasitic nematodes at the organic site in 1999 and 2000 when compared to untreated soil under white plastic mulch. Fumigation with methyl bromide significantly reduced the density of plant parasitic nematodes at the conventional sites in 1999 when compared to soil solarization or the untreated control. The results demonstrate that soil incorporation of urban plant debris can reduce the impact of soilborne pests in humid, subtropical climates such as Florida in organic and conventional pepper production systems. Technical Abstract: Soil management practices were examined for their effects on plant parasitic nematodes and soilborne diseases of field grown bell pepper (Capsicum annuum). Replicated field plots were established on a diversified organic vegetable farm that had been under certification for 5 years and on a conventional pepper farm that had been fumigated with methyl bromide and cropped annually to bell pepper for 25 years. In addition to the soil incorporation of 67 t ha-1 of urban plant debris (UPD), other soil management practices included no-till production into the residue remaining from a cover crop of Sunn Hemp (Crotalaria juncea) or Iron-clay Pea (Vigna unguiculata), established of raised polyethylene-mulched beds and soil solarization for a 6-8 week period. Soil fumigation with methyl bromide: chloropicrin was also evaluated at the conventional farm site. Experiments were conducted in 1999 and repeated in 2000. Soil incorporation of UPD significantly reduced the incidence of Pythium root rot in 2000 at the organic and Phytophthora blight in 1999 at the conventional site when compared to treatments not receiving UPD. Soil solarization and fumigation significantly reduced Phytophthora blight in 1999 at the conventional site, when compared to plots with untreated soil covered by polyethylene mulch, and in 1999 and 2000 when compared to the no-till treatments. Soil incorporation of UPD significantly reduced the density of plant parasitic nematodes in 2000 at the organic site and 1999 at the conventional site, when compared to treatments not receiving UPD. At the organic site, the density of plant parasitic nematodes was significantly higher in the minimum tillage plots when compared to soil solarization plots in both years. At the conventional site, significantly greater densities of Meloidogyne spp. were observed in the soil solarization and no-till Sunn Hemp treatments when compared to untreated soil covered by plastic mulch, while significant reductions in Meloidogyne spp. only occurred in the soil fumigation treatment. The results demonstrate that several nonchemical management practices can reduce the impact of soilborne pests for fresh market bell pepper production in a humid, subtropical climate. |
