Comparison of alternative pest and soil management strategies for Maine potato production systems

摘要: Potato acreage and total production in Maine have declined steadily since the 1960s. In 1991, a University of research team established large-scale, long-term, comparative study three factors that form foundation productive potato cropping systems: soil management, pest variety choice. This study, Ecosystem Project, included 96 main plots (5.8 ha total) near-by “component studies.” The project contrasted amended vs. unamended management strategies; conventional reduced-input bio-intensive disease stress susceptible tolerant varieties. Given recent concerns over resistance to pesticides increasing costs agricultural chemical inputs, systems provided encouraging results. Weed growth was similar systems. Colorado beetle thresholds were exceeded less often their densities lower system than Lady beetles, which are major aphid predators, more abundant compared with 5 6 years. Tuber yield quality maintained at high level system, although difficulties plant disease, nutrient weed contributed significantly yields system. Economic analysis indicated from 1993 1996, had greater return variable cost (avg. $973 -1 ) $890ha $578ha ). achieved rapid improvements quality: organic matter, water stable aggregates, potassium, soluble inorganic phosphorus contents increased while requirements for synthetic fertilizers reduced. These enhanced late-season crop vigor, canopy duration tuber quality, by 13% 30% 1994 1995, respectively, but not 1996. Improved vigor also benefited control efforts weed-suppressive crop. biointensive weeds controlled mechanically, biomass 1995. Conversely, consistently flea populations and, one two years, incidence Rhizoctonia. choice affected dynamics. Total density (all species considered together) almost all ratings higher on ‘Superior’ ‘Atlantic’ potato.