K. Delate
Iowa State University, Agronomy, Faculty Member
The growth of the organic industry is no longer confined to the East and West Coasts, as organic production and processing is booming in the Midwest as well. In Iowa alone, for example, there are over 100,000 acres in organic production... more
The growth of the organic industry is no longer confined to the East and West Coasts, as organic production and processing is booming in the Midwest as well. In Iowa alone, for example, there are over 100,000 acres in organic production farmed by over 500 ...
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Organic agriculture has expanded to a $13 billion industry in the United States in 2005, continuing the nearly decade-long trend of 20% annual growth. Despite the growth in organic agriculture, our scientific knowledge of organic... more
Organic agriculture has expanded to a $13 billion industry in the United States in 2005, continuing the nearly decade-long trend of 20% annual growth. Despite the growth in organic agriculture, our scientific knowledge of organic agriculture farming systems remains limited. Interest in sustainable and organic education at the university level has increased in recent years. To help address this need, the Iowa State University Graduate Program in Sustainable Agriculture (GPSA) was established in 2001 to meet three principal objectives: 1) provide students with the analytical and problem-solving skills required to meet the challenges confronting agriculture in the 21st century; 2) develop an innovative interdisciplinary and interdepartmental approach to graduate education; and 3) position Iowa State University at the forefront of institutions conducting research and extending knowledge about sustainable agricultural systems. As of 2004, more than 70 faculty from various departments and...
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Organic farming has increased to a $4.2 billion industry in the U.S. and continues to expand ≈20% annually. In Iowa alone, organic acreage for all crops has increased from 13,000 in 1995 to 120,000 in 1998. Organic farmers have requested... more
Organic farming has increased to a $4.2 billion industry in the U.S. and continues to expand ≈20% annually. In Iowa alone, organic acreage for all crops has increased from 13,000 in 1995 to 120,000 in 1998. Organic farmers have requested an unbiased analysis of natural soil amendments/fertilizers and compost products on the market for certified organic vegetable and herb production. In our first-year trials at the ISU Muscatine Island Research Farm in 1998, a total of 1,120 `Hungarian wax' pepper plants were transplanted into rows at 31 × 61-cm spacing. Four replications of seven fertilization treatments were planted within the field. The goal of the fertilization program was to obtain equivalent nitrogen and calcium rates in the organic and conventional systems. Leaf height was not significantly different in plants fertilized with organic compost (poultry litter-based) at 50 and 100 kg/ha N compared with conventional fertilizers (at 100 kg/ha N). All organic and conventional tr...
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Over the last several decades, agriculture in industrialized countries experienced a significant intensification as a result of the diffusion of mechanization, the widespread use of genetically improved genotypes, and the large-scale use... more
Over the last several decades, agriculture in industrialized countries experienced a significant intensification as a result of the diffusion of mechanization, the widespread use of genetically improved genotypes, and the large-scale use of off-farm inputs, mainly in the form of fossil fuel energy and synthetic fertilizers and pesticides. Under the pressure of the growing agro-industrial sector, which has been oriented to promote models based on large volumes and long-distance supply chains, intensification was accompanied by progressive specialization of farms and cropping systems (Ratnadass et al., 2012). Indeed, the reduction of diversity at the field, farm, and territory level, a result of a low number of crops, the shortening of crop rotations, and a decrease in the number of cultivated genotypes, is becoming evident in many agro-environments in developed countries.
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6 Organic Grains, Oilseeds, and Other Specialty Crops Kathleen Delate Department of Agronomy and Horticulture, Iowa State University, Ames ... Known in the trade as Pura-Maize (Hoegemeyer Hybrids, Inc., Hooper, NE), this strategy has... more
6 Organic Grains, Oilseeds, and Other Specialty Crops Kathleen Delate Department of Agronomy and Horticulture, Iowa State University, Ames ... Known in the trade as Pura-Maize (Hoegemeyer Hybrids, Inc., Hooper, NE), this strategy has received little research attention on its ...
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Emphasis on reducing emissions from the greenhouse gases (GHG), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) has increased in recent years in the USA, primarily for industry, transportation, energy and agricultural sectors.... more
Emphasis on reducing emissions from the greenhouse gases (GHG), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) has increased in recent years in the USA, primarily for industry, transportation, energy and agricultural sectors. In this study, we utilized on-farm data collected by the USDA-National Agricultural Statistics Service (NASS) Agricultural Resource Management Survey (ARMS), secured under an agreement with the USDA-Economic Research Service (ERS) to analyze the profitability of organic and conventional soybean production, based on changes that ‘green payments’ in a cap-and-trade system would introduce in agricultural markets in the USA. In particular, the analysis focused on establishing whether organic producers would be better positioned to sequester carbon (C) and reap the benefits of the C-offset scheme compared to conventional producers, given the differences in costs, management practices and environmental benefits between organic and conventional production...
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Summary In 1997, Iowa State University established the first US Land Grant University permanent faculty position in organic agriculture to assist farmers in the rapid expansion of organic production in that state. Research agendas,... more
Summary In 1997, Iowa State University established the first US Land Grant University permanent faculty position in organic agriculture to assist farmers in the rapid expansion of organic production in that state. Research agendas, developed in consultation with ...
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Research was conducted in a certified organic apple (Malus x domestica Borkh.) orchard in 2000 to determine the effect of organic pest management techniques on pest control, apple yields and microbial populations on harvested apples. In... more
Research was conducted in a certified organic apple (Malus x domestica Borkh.) orchard in 2000 to determine the effect of organic pest management techniques on pest control, apple yields and microbial populations on harvested apples. In Experiment I, apple colouring bags, sticky red spheres, kaolin particle film, kaolin particle film plus sticky red spheres, or colouring bags plus sticky red spheres were applied to Redfree, Jonafree, and Liberty apple trees in a split-plot design. Insects and diseases were sampled in the control and kaolin particle film treatments. Apple yields and insect damage ratings at harvest were determined for all treatments. There was a significant treatment x cultivar interaction related to insect damage on apples. Insect and disease damage ratings throughout the growing season and at harvest were lowest in Jonafree trees treated with kaolin particle film or colouring bags. There was no effect of treatment on beneficial insects during the growing season. Ma...
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As organic agriculture continues to grow, pressure from students and the public to develop novel curricula to address specific needs of this sector of agriculture also will increase. More students from the cities and with limited... more
As organic agriculture continues to grow, pressure from students and the public to develop novel curricula to address specific needs of this sector of agriculture also will increase. More students from the cities and with limited background in production agriculture are enrolling in agricultural programs with special interest in organic production. This new student population is demanding new curricula based on a better understanding of agroecology principles and more experiential training. Several universities throughout the nation have engaged in a profound curriculum transformation to satisfy the emerging need of students in organic production. This workshop was organized to bring together experts that are working on different organic and sustainable agriculture curricula throughout the country to share their experiences and lessons learned. Most of these curricula include a traditional classroom teaching component, a major experiential component, a student farm for hands-on expe...
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With the continuing 20% growth rate in the organic industry, organic vegetable crop production has increased to 98,525 acres in the United States. The requirement for certified organic vegetable producers to implement a soil-building plan... more
With the continuing 20% growth rate in the organic industry, organic vegetable crop production has increased to 98,525 acres in the United States. The requirement for certified organic vegetable producers to implement a soil-building plan has led to the development of soil fertility systems based on combinations of organic fertilizers and cover crops. To determine optimal soil fertility combinations, conventional and organic bell pepper (Capsicum annuum) production was evaluated from 2001 to 2003 in Iowa, comparing combinations of two synthetic fertilizers and three compost-based organic fertilizers, and a cover crop treatment of hairy vetch (Vicia villosa) and rye (Secale cereale) in a strip-tilled or fully incorporated cover crop system. Organic pepper growth and yields equaled or surpassed conventional production when nitrogen (N) was provided at 56 or 112 kg·ha−1 from compost-based organic fertilizer. Soil analysis revealed higher N in plots where cover crops were tilled compare...
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By 2003, organic apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] production had increased to 5626 ha in the United States and to 2964 ha in New Zealand by 2002. Common problems facing organic apple growers in the humid... more
By 2003, organic apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] production had increased to 5626 ha in the United States and to 2964 ha in New Zealand by 2002. Common problems facing organic apple growers in the humid regions of New Zealand and the United States include effective management strategies for apple scab [Venturia inaequalis (Cooke)] and insect pests. Experiments conducted in Iowa in 2003–2004 demonstrated the effectiveness of a kaolin clay- and spinosad-based insecticide program in maintaining codling moth [Cydia pomonella (L.)] damage levels to less than 5% in the scab-resistant cultivars Enterprise, Liberty, Redfree, and Gold Rush. Similar pest management systems have been developed in New Zealand to comply with export standards and quarantines. The use of codling moth granulosis virus and a spinosad-based insecticide have led to reduced pest pressure and to an increase in organic exports with a 41% premium price over conventional apples. However, a...
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The global market for total organic product sales was $20 billion in 2005, continuing an annual growth rate of 20% to 35%. In the United States, there were 937,000 ha of certified organic land in 2003 with 5626 ha of organic apples [Malus... more
The global market for total organic product sales was $20 billion in 2005, continuing an annual growth rate of 20% to 35%. In the United States, there were 937,000 ha of certified organic land in 2003 with 5626 ha of organic apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.]. Increases in organic fruit production have been associated with improved pest management methods, the use of disease-resistant cultivars, and organic-focused marketing schemes. Often constrained by lower apple yields and smaller fruit size compared with conventional counterparts, key challenges for organic growers include regulation of nutrient cycling processes to maintain crop yields while minimizing the need for external inputs. In local or regional organic markets, disease-resistant apple cultivars, such as ‘Enterprise’, ‘Liberty’, ‘Redfree’, and ‘Gold Rush’, have gained increased acceptance, whereas exporting countries have continued their use of cultivars susceptible to scab [Venturia inae...
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Abstract That the health of soils, plants, animals, and people are linked is an ancient idea that still resonates. Growing evidence links farm management, soil health, and plant health but relationships among soil health, food crop... more
Abstract That the health of soils, plants, animals, and people are linked is an ancient idea that still resonates. Growing evidence links farm management, soil health, and plant health but relationships among soil health, food crop nutritional quality, and human health are less understood. Numerous studies compare organic with conventional farming in order to shed light on these links. Organic farming systems utilize carbon-based amendments, diverse crop rotations, and cover crops to build soil fertility. These practices increase biologically available soil organic matter and beneficial soil microbe and invertebrate activities, improve soil physical properties, reduce disease potential, and increase plant health. To date, comparisons of nutrient content between organic and conventional foods have been inconsistent. Recent evidence suggests that organically grown fruits and vegetables contain higher levels of health promoting phytochemicals, possibly linked to greater plant stress, rhizosphere microbial communities, and/or lower available nitrogen. But the overlap in management practices among farming systems make broad generalizations difficult. Moreover, environmental and crop species and/or cultivar interactions may exert stronger effects than management. Here we summarize the known factors influencing soil and plant health and link these with food-crop quality and human health. Though this paper draws primarily from research on organic farming, management practices that enhance soil, plant, and human health remain an important goal for all sustainable food production systems.
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Based on the interest of organic and conventional farmers in Iowa in long-term analysis of organic systems, the Neely-Kinyon Long-Term Agroecological Research (LTAR) site was established in 1998 to examine the agronomic and economic... more
Based on the interest of organic and conventional farmers in Iowa in long-term analysis of organic systems, the Neely-Kinyon Long-Term Agroecological Research (LTAR) site was established in 1998 to examine the agronomic and economic performance of conventional and organic systems, using certified organic production practices. We report the results of the economic analysis from 3 years of production (1999–2001). Using organic price premiums for organic crops, returns for corn within the organic corn-soybean-oat and corn-soybean-oat-alfalfa rotations were significantly greater than conventional corn-soybean rotation returns (US$126 ha−1). Com returns were not significantly different between the two organic rotations, at US$655 ha−1 and US$674 ha−1, respectively. Returns for soybean within the organic corn-soybean-oat and com-soybean-oat-alfalfa rotations were not significantly different, at US$1233 ha−1 and US$1326 ha−1, respectively. Organic soybean returns were significantly greater...
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... 358 Kathleen M . Delate, J. Kenneth Grace, John W. Armstrong, Carrie H. M. Tome ... Thirty termite workers (pseudergates, or undifferentiated individuals older than the third instar) were placed in a Petri dish (diameter 100 mm,... more
... 358 Kathleen M . Delate, J. Kenneth Grace, John W. Armstrong, Carrie H. M. Tome ... Thirty termite workers (pseudergates, or undifferentiated individuals older than the third instar) were placed in a Petri dish (diameter 100 mm, height 15 mm) provided with a moistened filter-paper ...
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ABSTRACT
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... Two disposable poly-styrene Petri dishes (1 50 x 25 mm) were connected by a glass tube (8 x 130 mm). ... The small dishes were inverted and placed in the center of the larger Petri dishes where the sand had been excavated to... more
... Two disposable poly-styrene Petri dishes (1 50 x 25 mm) were connected by a glass tube (8 x 130 mm). ... The small dishes were inverted and placed in the center of the larger Petri dishes where the sand had been excavated to accommodate the bait station. ...
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Research Interests: Crop management and CM
In a national survey and through statewide focus groups, organic farmers identified pest management and soil fertility as their most critical vegetable research needs. In response, a long- term experiment was established to compare pepper... more
In a national survey and through statewide focus groups, organic farmers identified pest management and soil fertility as their most critical vegetable research needs. In response, a long- term experiment was established to compare pepper (Capsicum annuum L.) growth, productivity, insect populations, harvest cullage and postharvest weight loss under conventional and organic management. Treatments from the first 3 years (1998
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Formosan subterranean termites, Coptotermes formosanus Shiraki, were exposed to ⩾ 95% or 50% carbon dioxide atmospheres for intervals of 24-120 h at 26(±3)°C. A 24-h exposure to ⩾ 95% carbon dioxide caused significant termite mortality,... more
Formosan subterranean termites, Coptotermes formosanus Shiraki, were exposed to ⩾ 95% or 50% carbon dioxide atmospheres for intervals of 24-120 h at 26(±3)°C. A 24-h exposure to ⩾ 95% carbon dioxide caused significant termite mortality, but 60 h were required for complete mortality. Exposure to 50% carbon dioxide for 60 h resulted in approximately 70% termite mortality, while complete mortality was recorded after 120 h. When termites were sealed in wooden blocks (90 × 90 × 152 mm), 72-96 h exposure to ⩾ 95% carbon dioxide was necessary for complete control. A limited study with Cryptotermes brevis (Walker) suggested that this drywood termite is also susceptible to carbon dioxide fumigation, although slightly longer exposures may be required than with C. formosanus. Carbon dioxide-modified atmospheres are a viable alternative to conventional fumigants for vault fumigation of termite-infested materials, and may also be applicable to larger-scale fumigations to control structural pests.
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Research Interests: Crop Science and Crop
Abstract Scientific studies across the US have demonstrated the economic viability of organic cropping systems. Of particular interest to farmers contemplating organic production is the economic viability of the farm during the... more
Abstract Scientific studies across the US have demonstrated the economic viability of organic cropping systems. Of particular interest to farmers contemplating organic production is the economic viability of the farm during the transition-to-organic period, which is ...