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Plant Sciences

Proceedings of the Integrated Crop Management Conference

1989

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Some Studies On The Use Of Aca On Corn, I. C. Anderson Dec 1989

Some Studies On The Use Of Aca On Corn, I. C. Anderson

Proceedings of the Integrated Crop Management Conference

ACA. a N fertilizer additive, is now marketed by United Agri Products of Greeley, Colorado. ACA was developed by Amoco in the mid-1970s. Originally, they developed a soluble form of Zn to market in their anhydrous. The form of Zn was zinc acetate. They noted in some of their tests that at low rates of Zinc acetate they obtained yield increases under conditions where there was no indication from foliar Zn analysis that soil Zn was inadequate. Zinc acetate in strong ammonia solutions exists as 1 molecule of Zn with 2 molecules of acetate, and in the presence of adequate ...


The Leopold Center For Sustainable Agriculture: An Overview, Dennis R. Keeney Dec 1989

The Leopold Center For Sustainable Agriculture: An Overview, Dennis R. Keeney

Proceedings of the Integrated Crop Management Conference

The Leopold Center for Sustainable Agriculture was established in the 1987 Groundwater Protection Act. CH. 225, Sec. 230. The legislation defines sustainable agriculture as "the appropriate use of crop and livestock systems and agricultural inputs supporting those activities which maintain economic and social viability while preserving the high productivity and quality of Iowa's land."


Indices For Adjusting Fertilizer Nitrogen Rates, Alfred M. Blackmer Dec 1989

Indices For Adjusting Fertilizer Nitrogen Rates, Alfred M. Blackmer

Proceedings of the Integrated Crop Management Conference

Nitrogen fertilizer recommendations for corn production in Iowa have been based on yield expectations and adjustments for estimated amounts of N supplied by animal manures or previous legume crops. These recommendations include adjustments for three groups of soil associations, which generally reflect different parts of the state. However, the recommendations have no provisions for adjusting rates of N fertilizer application for weather conditions, management practices, or different soil types within the three groups of soil associations. This situation exists because there has been a lack of suitable methods for making N fertilizer recommendations that are site specific (i.e. adjusted ...


Pod Test For Phomopsis Seed Decay Of Soybean, Denis C. Mcgee Dec 1989

Pod Test For Phomopsis Seed Decay Of Soybean, Denis C. Mcgee

Proceedings of the Integrated Crop Management Conference

Phomopsis seed decay, caused by the fungus Phomopsis longicolla is a major problem to soybean seed producers, because of adverse effects on seed germination. Control can be achieved by application of benzimidazole fungicides to the growing seed crop. Very often, the disease is not severe enough to justify application costs. A predictive method. therefore, was developed to identify fields that should be sprayed.


Soybean Cyst Nematode, Laura E. Sweets Dec 1989

Soybean Cyst Nematode, Laura E. Sweets

Proceedings of the Integrated Crop Management Conference

The damage caused by soybean cyst nematode led the Chinese to call it yellow dwarf disease of soybeans when it was first identified in China in 1915. Soybean cyst nematode was first reported in the United States in North Carolina in 1954. Since then it has been found in at least 26 midwestern and southeastern states. It was first found in Iowa in Winnebago County in 1978. Soybean cyst nematode has been confirmed in 46 Iowa counties- see map below.


Iowa Farmers' Practices And Opinions About Lisa, Paul Lasley Dec 1989

Iowa Farmers' Practices And Opinions About Lisa, Paul Lasley

Proceedings of the Integrated Crop Management Conference

Data from the 1989 Iowa Farm and Rural Life Poll of 2,016 randomly selected farmers are used to examine producers' use of practices to reduce inputs and their opinions about current agricultural practices. In this study, farmers were asked the extent to which they use a set of recommended practices to reduce their use of chemical fertilizer and pesticides (Table 1). Although the majority of farmers use these recommended practices, there remains significant numbers of producers who either do not use the practices or make only limited use of them. For example, 26 percent of the respondents reported they ...


Corn Diseases, C. A. Matinson Dec 1989

Corn Diseases, C. A. Matinson

Proceedings of the Integrated Crop Management Conference

The dry weather of the last two years has decreased the apparent level of corn diseases, but they were there. Some were not obvious yet others were more severe than normal. A new leaf disease caused serious problems in Northern Illinois seed production and on a few hybrids.


The Value Of Weed Control In Alfalfa, Brian J. Lang Dec 1989

The Value Of Weed Control In Alfalfa, Brian J. Lang

Proceedings of the Integrated Crop Management Conference

Good weed control is essential for effective alfalfa establishment and production. Weeds compete with alfalfa for water, nutrients, light,-and space. This competition can result in decreased yield, qualify, and palatability, increased harvest problems, and reduced .stand persistence. The proper and timely use of cultural and chemical weed control methods are critical in the establishment and maintenance of a competitive, vigorous growing and dense stand of alfalfa. Before the advent of selective herbicides, weed control in alfalfa stands was accomplished mainly through the use of cultural practices applied before and after establishment. Today, herbicides are available which provide the producer ...


Impact Of Biotechnology On Crop Production, Protection, And Utilization, Walter R. Fehr Dec 1989

Impact Of Biotechnology On Crop Production, Protection, And Utilization, Walter R. Fehr

Proceedings of the Integrated Crop Management Conference

Since the beginning of civilization, humankind has modified plants to better fit their needs for production of food, feed, and fiber. Even before the days of modem science, cultivators selected plants with high productivity, the ability to withstand disease, and the size, shape, and color of the seed. The individual preferences of the cultivators led to thousands of different "varieties," particularly in the area where the crop originated.


Biological Weed Management, Robert Hartzler Dec 1989

Biological Weed Management, Robert Hartzler

Proceedings of the Integrated Crop Management Conference

The classical definition of biological control has referred to the use of natural enemies (whether introduced or otherwise manipulated) to control a pest organism, whether it be an insect, disease, or weed. In recent years the concept has been expanded to include other forms of non-chemical control that are based on biology. There have been several dramatic success stories involving biological control of weeds in the past, and this is one potential means of reducing our dependency upon synthetic chemicals for weed control. This paper will provide a brief overview of some of the areas of interest and their potential ...


Pesticide Management Areas And Use Restriction In Iowa, David E. Stoltenberg Dec 1989

Pesticide Management Areas And Use Restriction In Iowa, David E. Stoltenberg

Proceedings of the Integrated Crop Management Conference

In December of 1987, the Environmental Protection Agency (EPA) released Agricultural Chemicals in Groundwater: Proposed Pesticide Strategy. The strategy is designed to ensure that the potential health and environmental impacts resulting from contamination of groundwater with pesticides are fully considered in pesticide registration decisions so that unreasonable risks can be identified and avoided. A critical component of the strategy is the prominent role that individual states can potentially have in future regulation of pesticide use. Of many individuals potentially affected by EPA's proposed strategy, few have felt any impact of the strategy on current pesticide use practices. However, since ...


Weed Thresholds, Harold D. Coble Dec 1989

Weed Thresholds, Harold D. Coble

Proceedings of the Integrated Crop Management Conference

Four distinct pest management strategies are generally recognized by specialists: avoidance, prevention, suppression, and eradication. Avoiding awed population may be possible under certain circumstances, such as using crop rotation to avoid a particular weed problem, or planting the crop aftermost weeds of a particular species have germinated. However, this strategy is very limited with weeds since almost all fields are infested with a potentially economically damaging level of weed seeds. Prevention, simply stated, means not allowing a weed population to become established in a field. This is a lofty goal because of the propensity of weed seeds to spread from ...


Fertilizer Placement In Tillage Systems, George Rehm Dec 1989

Fertilizer Placement In Tillage Systems, George Rehm

Proceedings of the Integrated Crop Management Conference

Stimulated by concerns for farm profitability, there has been an increasing interest in efficiency of fertilizer use in recent years. Consequently, there have been several questions which relate to the effect of placement on the efficient use of fertilizers.


Fungicide Seed Treatments, Laura E. Sweets Dec 1989

Fungicide Seed Treatments, Laura E. Sweets

Proceedings of the Integrated Crop Management Conference

Seed treatment, as defined by the Federal Seed Act, means "...seed given an application of a substance or subjected to a process designed to reduce or control, repel disease organisms, insects, or other pests which attack seeds or seedlings growing therefrom." A fungicide seed treatment is the application of a fungicide to the seed to protect it from rot or decay caused by disease-causing microorganisms 1n the soil, on the seed, or in the seed.


Plant Pathology Update, Laura E. Sweets Dec 1989

Plant Pathology Update, Laura E. Sweets

Proceedings of the Integrated Crop Management Conference

No abstract provided.


Tillage And Weed Management, Micheal D. K. Owen Dec 1989

Tillage And Weed Management, Micheal D. K. Owen

Proceedings of the Integrated Crop Management Conference

Tillage is the most important factor influencing weed management in row crops. Any tillage treatment can be considered as a weed management strategy: the primary function of tillage is to manage weeds. The effects of tillage on weed management can be direct or indirect. Examples of the direct effects of tillage on weed management would be the physical destruction of weeds by cultivation or the dilution of the soil weed seed reservoir. Indirect effects include the relative placement of herbicides in the soil and the impact on herbicide degradation. Another factor that must be considered is the affect of tillage ...


Rapid Diagnostic Kits For Plant Diseases, Laura E. Sweets Dec 1989

Rapid Diagnostic Kits For Plant Diseases, Laura E. Sweets

Proceedings of the Integrated Crop Management Conference

The accurate diagnosis of a plant disease is the most important step in developing an effective management strategy for that disease. Yet diagnosing plant diseases is often difficult and frustrating. Distinctive symptoms may not develop until late in the disease cycle. Many plant diseases fail to produce obvious symptoms or produce general, nondescriptive symptoms, such as yellowing, stunting or wilting, that could be produced by a number of biotic or abiotic factors. Recent advances in molecular biology and biotechnology are being used to develop rapid, sensitive diagnostic kits for detection of plant diseases.


Soil Tilth And Sustainable Agriculture, J. L. Hatfield Dec 1989

Soil Tilth And Sustainable Agriculture, J. L. Hatfield

Proceedings of the Integrated Crop Management Conference

Soil tilth is defined as the "physical condition of soil as related to its ease of tillage, fitness as a seedbed, and its impedance to seedling emergence and root penetration." Sustainable agriculture has been defined in Iowa as "the appropriate use of crop and livestock systems and agricultural inputs supporting those activities which maintain economic and social viability while preserving the high productivity and quality of Iowa's land." Thus, it is not possible to discuss sustainable agriculture without considering soil tilth. Development of a sustainable agricultural system requires a viable and stable soil resource, so we will explore linkages ...


Isu Perspective On Sustainable Agriculture, Michael Duffy Dec 1989

Isu Perspective On Sustainable Agriculture, Michael Duffy

Proceedings of the Integrated Crop Management Conference

No abstract provided.


Sustainable Agriculture: A National Perspective, John E. Ikerd Dec 1989

Sustainable Agriculture: A National Perspective, John E. Ikerd

Proceedings of the Integrated Crop Management Conference

Public fears regarding possible contamination of foods with agricultural chemicals have combined with persistent concerns for soil conservation and water quality to make agriculture and the environment a major national issue. Fears related to Alar in apples and cyanide in imported grapes, for example, replaced fears of another drought in summer '89 news headlines. The Food Market Institute reported that 82 percent of food shoppers responding to a recent survey said that chemical residues in foods posed a "serious hazard" to their health (Steimel).


Water Quality Monitoring- What Is Being Detected?, David E. Stoltenberg Dec 1989

Water Quality Monitoring- What Is Being Detected?, David E. Stoltenberg

Proceedings of the Integrated Crop Management Conference

Due to the concern over the impact of agricultural chemical use on water quality, the amount of water quality monitoring data has increased substantially during the last few years. Several groundwater surveys for nitrates and pesticides have been conducted in the Midwest. A partial list includes surveys conducted in Illinois, Kansas. Minnesota. Missouri. Nebraska. Ohio, and Wisconsin.


Cooperative Extension Service On-Farm Demonstration Projects, Gerald Miller Dec 1989

Cooperative Extension Service On-Farm Demonstration Projects, Gerald Miller

Proceedings of the Integrated Crop Management Conference

Demonstration projects at Iowa State University are a major program thrust supported by separate contracts with state agencies. The projects are • the Integrated Farm Management Demonstration Project, • the Big Spring Basin Demonstration Project, and • the Model Farms Demonstration Project.


Weed Science Update 1990, Micheal D. K. Owen Dec 1989

Weed Science Update 1990, Micheal D. K. Owen

Proceedings of the Integrated Crop Management Conference

There are a number of major considerations with regards to weed management in 1990. Several weed species have been identified as potentially serious statewide problems. Herbicide carryover has the potential to be an issue in 1990 and should be considered seriously as decisions are made for crop rotation, tillage, and herbicide selection. Finally, there are several herbicide candidates that demonstrate significant weed control and may impact overall weed management choices in 1990.


Effect Of Enrvironmental Conditions On Weed/Herbicide Interactions, Micheal D. K. Owen Dec 1989

Effect Of Enrvironmental Conditions On Weed/Herbicide Interactions, Micheal D. K. Owen

Proceedings of the Integrated Crop Management Conference

Environmental conditions, notably soil moisture, temperature, radiation, and, relative humidity, affect plant growth. Further, the environment affects herbicide properties whether soil-applied or applied postemergence to plants. The interaction of the herbicidal properties and the plant growth characteristics results in the plant response. Generally, the plant growth characteristics are the most important component influencing herbicide activity. This paper will discuss the effect of environmental conditions on plants, herbicides, and the ability of several herbicide additives to improve plant response to herbicides applied postemergence.


Herbicide Movement In Soils, Geoge F. Czapar Dec 1989

Herbicide Movement In Soils, Geoge F. Czapar

Proceedings of the Integrated Crop Management Conference

The effect of agricultural chemicals on groundwater quality continues to be a major concern. Although point source contamination is recognized as a significant factor, the extent of herbicide leaching from normal field use is not clear. Since herbicides are used on approximately 98% of the corn and soybeans acres in Iowa, it is important to understand herbicide movement under normal conditions.


Climate Changes And Impacts On Midwest Crop Production, S. Elwynn Taylor Dec 1989

Climate Changes And Impacts On Midwest Crop Production, S. Elwynn Taylor

Proceedings of the Integrated Crop Management Conference

Climate change has become a topic of worldwide concern. There are few locations where the general population has a greater vested interest in climate change than the Midwest. The economy of most Midwest communities is pr1marily dependent upon agriculture, and weather remains the primary uncontrollable factor inducing uncertainty in production. Perhaps the greatest potential effect of climate change is the influence on crops.