Submitted to: Renewable Agriculture and Food Systems
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/8/2004
Publication Date: 7/1/2004
Citation: Chellemi, D.O., Rosskopf, E.N. 2004. Yield potential and soil quality under alternative crop production practices for fresh market pepper. Renewable Agriculture and Food Systems. 19:168-175. Interpretive Summary: This research was conducted to measure the effects of alternative crop production practices on the yield potential of pepper, the incidence of soilborne diseases, populations of plant parasitic nematodes and selected indicators of soil quality. The results indicated that addition of an organic amendment can reduce the incidence of soilborne disease and the density of plant parasitic nematodes. This has important implications as a potential nonchemical alternative to soil fumigation with methyl bromide. The results also demonstrated that no-till production systems for fresh market vegetables using the stubble remaining from a summer legume are not technically feasible in humid, subtropical climates due to the rapid emergence of weeds. Finally, this study showed using replicated experimental designs that organic production systems for fresh market pepper will not achieve yields equivalent to the state-wide average for conventionally grown pepper.
Technical Abstract: Replicated field plots were established in sites with differing histories of crop production to measure parameters of soil quality and the yield potential of fresh market pepper (Capsicum annum) under alternative crop production practices and organic amendments. Site 'O' was an organic vegetable farm under certification for five years. Site 'C' was a conventional pepper farm fumigated with methyl bromide for 25 consecutive years. Production practices evaluated included raised beds covered by white plastic mulch, soil solarization, and no-till in a stubble crop of sunn hemp (Crotolaria juncea) or iron-clay pea (Vigna unguiculata). Soil fumigation with methyl bromide: chloropicrin was also evaluated at site 'C'. Plots received 0 or 67 mt per ha of urban plant debris (UPD) as an organic amendment. Experiments were conducted in 1999 and 2000. A significant interaction between UPD and production practices was observed for soil pH. Soil organic carbon was significantly increased by addition of UPD in the second year. No-till production resulted in high populations of plant parasitic nematodes while addition of UPD reduced nematode populations. Survival of transplanted pepper seedlings was reduced in the no-till treatments due to intense weed pressure. Addition of UPD reduced the incidence of soilborne disease and increased yields in all production practices except soil fumigation. Yields equal to or above the statewide average for conventional production systems were obtained with soil fumigation and soil solarization. The incidence of soilborne disease was substantially lower in the organic site.