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2004

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Full-Text Articles in Life Sciences

Systematics Of Dirca (Thymelaeaceae) Based On Its Sequences And Issr Polymorphisms, James A. Schrader, William R. Graves Dec 2004

Systematics Of Dirca (Thymelaeaceae) Based On Its Sequences And Issr Polymorphisms, James A. Schrader, William R. Graves

Horticulture Publications

The genus Dirca consists of three disjunct species of shrubs. Dirca palustris is found in the eastern United States and adjacent Canada; D, occidcntahs is Umited to six counties near the San Francisco Bay in California; and the recently discovered D, mcxicana is known from one isolated population in northeastern Mexico. The three species have been described and classified according to morphological characters, but the morphological evidence does not provide a clear assessment of the relationships among the species. Morphologically D. mexicana most closely resembles D. occidenlalis., but known biogeographical trends raise doubt regarding how the three species are interrelated ...


In Vivo Dose-Response Of Insects To Hz-2v Infection, John P. Burand, Christopher P. Rallis Dec 2004

In Vivo Dose-Response Of Insects To Hz-2v Infection, John P. Burand, Christopher P. Rallis

John Burand

Background Hz-2V infection of female Helicoverpa zea moths is manifested as insects that are either sterile "agonadal" individuals with malformed reproductive tissues or fertile asymptomatic carriers which are capable of transmitting virus on to their progeny. Virus infected progeny arising from eggs laid by asymptomatic carrier females may themselves be either sterile agonadals or asymptomatic carriers. Results By injecting virus into female moths, a correlation was established between virus doses administered to the females and the levels of resulting asymptomatic and sterile progeny. Conclusions The results of these experiments indicate that high virus doses produced a higher level of agonadal ...


In Vivo Dose-Response Of Insects To Hz-2v Infection, John Burand, Christopher Rallis Dec 2004

In Vivo Dose-Response Of Insects To Hz-2v Infection, John Burand, Christopher Rallis

Microbiology Department Faculty Publication Series

Background Hz-2V infection of female Helicoverpa zea moths is manifested as insects that are either sterile "agonadal" individuals with malformed reproductive tissues or fertile asymptomatic carriers which are capable of transmitting virus on to their progeny. Virus infected progeny arising from eggs laid by asymptomatic carrier females may themselves be either sterile agonadals or asymptomatic carriers. Results By injecting virus into female moths, a correlation was established between virus doses administered to the females and the levels of resulting asymptomatic and sterile progeny. Conclusions The results of these experiments indicate that high virus doses produced a higher level of agonadal ...


Central Crops And Soils Research Station Highmore, South Dakota: Annual Progress Report, 2004, Agricultural Experiment Station, Plant Science Department Dec 2004

Central Crops And Soils Research Station Highmore, South Dakota: Annual Progress Report, 2004, Agricultural Experiment Station, Plant Science Department

Agricultural Experiment Station and Research Farm Annual Reports

This is the 2004 progress report for the Central Crops and Soils Research Station at Highmore, South Dakota State College. This document represents the research conducted at the Station during the 2004 crop season including: temperature and precipitation data, field evaluations of woody plant materials, optimal management of drought-tolerant legumes and warm season annual grasses, winter wheat breeding, oat research, weed control fertilizer and soil test effects, aphid infestations, barley yellow dwarf Incidence, plant growth and yield of winter wheat in relation to planting date and seed treatment, small grain variety performance trials, corn breeding, and an evaluation of native ...


West River Ag Center Crops And Soils Research Annual Progress Report, 2004, Agricultural Experiment Station Dec 2004

West River Ag Center Crops And Soils Research Annual Progress Report, 2004, Agricultural Experiment Station

Agricultural Experiment Station and Research Farm Annual Reports

This is the 2004 progress report of the West River Crops and Soils Research Projects, South Dakota Agricultural Experiment Station. This document includes reports on: weather and climate, wheat and grain variety trials, management and tillage, and weed and pest control.


Expression Of The Tobacco Β- 1,3-Glucanase Gene, Pr-2d, Following Induction Of Sar With Peronospora Tabacina, Deanna L. Funnell, Christopher B. Lawrence, Jeffrey F. Pedersen, Christopher L. Schardl Dec 2004

Expression Of The Tobacco Β- 1,3-Glucanase Gene, Pr-2d, Following Induction Of Sar With Peronospora Tabacina, Deanna L. Funnell, Christopher B. Lawrence, Jeffrey F. Pedersen, Christopher L. Schardl

Papers in Plant Pathology

Systemic acquired resistance (SAR) is induced following inoculation of Peronospora tabacina sporangia into the stems of Nicotiana tabacum plants highly susceptible to the pathogen. Previous results have shown that accumulation of acidic P-1,3-glucanases (PR-2's) following induction of SAR by P. tabacina may contribute to resistance to P. tabacina. We showed that up-regulation of the PR-2 gene, PR-2d, following stem inoculation with P. tabacina, is associated with SAR. Studies using plants transformed with GUS constructs containing the full length promoter from PR-2d or promoter deletions, provided evidence that a previously characterized regulatory element that is involved in response to ...


Distance Between Pollen Donor And Recipient Influences Fruiting Success In Slickspot Peppergrass, Lepidium Papilliferum, Ian C. Robertson, Amy C. Ulappa Dec 2004

Distance Between Pollen Donor And Recipient Influences Fruiting Success In Slickspot Peppergrass, Lepidium Papilliferum, Ian C. Robertson, Amy C. Ulappa

Biology Faculty Publications and Presentations

Plant populations are often spatially structured owing to limited dispersal of pollen and seed. Mating between neighboring individuals in such populations often leads to reduced reproductive performance relative to matings between distant individuals. This response, which may be a result of inbreeding depression or prezygotic mating barriers, was investigated for slickspot peppergrass, Lepidium papilliferum L. (Brassicaceae), a rare insect-pollinated mustard endemic to sagebrush–steppe habitat in southwestern Idaho. Through hand pollination experiments we found that individual plants receiving pollen from distant sources (75–100 m and 6.5–20 km away) had significantly higher percent fruit sets than those relying ...


Knowing The Risk Of Soybean Rust By Comparison With Brazil, X. B. Yang, Emerson M. Del Ponte, Ana Paula Dias Dec 2004

Knowing The Risk Of Soybean Rust By Comparison With Brazil, X. B. Yang, Emerson M. Del Ponte, Ana Paula Dias

Integrated Crop Management News

One of the common questions we receive is whether to move away from soybean because of the risk of soybean rust (SBR). Although studies indicate that the U.S. soybean production region is suitable to this disease, many experts believe outbreaks of the disease are likely to be sporadic.


Isu Introduces The Corn And Soybean Initiative, Brian Gene Meyer Dec 2004

Isu Introduces The Corn And Soybean Initiative, Brian Gene Meyer

Integrated Crop Management News

The Corn and Soybean Initiative is a new effort at Iowa State University to better serve the needs of Iowa's number-one-in-the-nation corn and soybean growers. "Iowa has the best crop producers in the country and they just keep getting better," said Greg Tylka, coordinator of the initiative and a professor of plant pathology. "Iowa State's Corn and Soybean Initiative will work to make sure that trend continues by providing a central access point for research-based production information and education.


Workshop In Using Living Mulch Systems For Grain Crop Production, Palle Pedersen, Jodee Roland Dec 2004

Workshop In Using Living Mulch Systems For Grain Crop Production, Palle Pedersen, Jodee Roland

Integrated Crop Management News

Incorporation of perennial legumes and cover crops into our row cropping systems and reduction of tillage will reduce soil erosion and concurrent loss of phosphorous and nitrogen to the surface water. Kura clover (Trifolium ambiguum) is a relatively new forage legume in North America that can be used in a living mulch system. It has an excellent forage yield and is persistent under a wide range of soil and climatic environments. Iowa Department of Agriculture and Land Stewardship, and Integrated Farm/Livestock Management Demonstration Program, with the assistance of Iowa State University Extension, are currently funding a large on-farm demonstration ...


Commercial Pesticide Applicator Training Sessions For Spring 2005, James A. Fawcett, Virgil L. Schmitt Dec 2004

Commercial Pesticide Applicator Training Sessions For Spring 2005, James A. Fawcett, Virgil L. Schmitt

Integrated Crop Management News

With the arrival of Asian soybean rust in this country, many commercial applicators are adding agricultural diseases (category 1C) to their certification so that they can apply fungicides. Most agricultural commercial applicators are certified in Ag Weeds (category 1A), and many are certified in Ag Insects (category 1B), but not very many are certified in Ag Diseases (category 1C).


The Phosphorus Index, U.S. Department Of Agriculture Dec 2004

The Phosphorus Index, U.S. Department Of Agriculture

Proceedings of the Integrated Crop Management Conference

The Phosphorus Index is a tool used to assess the potential for phosphorus (P) to move from agricultural fields to surface water. It uses an integrated approach that considers soil and landscape features as well as soil conservation and P management practices in individual fields. These characteristics include source factors such as soil test P; total soil P; rate, method, and timing of P application from commercial fertilizer, manure, and other organic sources; and erosion. Transport factors include sediment delivery, relative field location in the watershed, soil conservation practices, precipitation, runoff, and tile flow/subsurface drainage. Erosion, runoff and drainage ...


With High Fertilizer Prices Is It Business As Usual Or Should Fertilization Practices Change?, John E. Sawyer Dec 2004

With High Fertilizer Prices Is It Business As Usual Or Should Fertilization Practices Change?, John E. Sawyer

Proceedings of the Integrated Crop Management Conference

After the spike in natural gas price in the winter of 2000-2001 the price of natural gas and N fertilizers have fluctuated, but remained above previous historic levels. Seasonal trends have also resulted in both N product availability and high cost issues, including this fall. Recently, similar problems have hit phosphate and potash fertilizers where world demand and production problems (hurricanes affecting phosphate production in Florida) have negatively affected product price and supply in the United States. With these trends, are there fertilizer use practices that should change, or does crop response to fertilization pay no matter the cost? Crop ...


Iron Deficiency Chlorosis: Management For Hot Spots And Whole Fields, Seth Naeve Dec 2004

Iron Deficiency Chlorosis: Management For Hot Spots And Whole Fields, Seth Naeve

Proceedings of the Integrated Crop Management Conference

Iron Deficiency Chlorosis impacts soybean yields primarily in the Western Corn Belt. Iron Deficiency Chlorosis (more commonly iron chlorosis) is a complex plant disorder that is driven primarily by a nutrient deficiency (iron), usually manifested where soil pH is greater than 7.5. Although Midwestern soils are abundant in iron, higher pH soils cause iron to be in a form that is less available to plants, i.e. it cannot be absorbed. Iron chlorosis, however, does not occur in all high pH soils. A multitude of other soil factors interact to impact iron chlorosis in soybean. Soil chemical properties such ...


Do We Really Need To Inoculate Our Fields?, Palle Pedersen Dec 2004

Do We Really Need To Inoculate Our Fields?, Palle Pedersen

Proceedings of the Integrated Crop Management Conference

Currently, there is a lot of interest in soybean seed inoculation. Several new products have entered the market and created a renewed interest in seed inoculation even on fields that have a history of soybean production. As a result of this renewed interest and the lack of information from Iowa, a soybean inoculant evaluation trial was initiated this year in Iowa to evaluate these products. Our objective was to determine if we need to adjust our current recommendations when using inoculants. Twelve different inoculants were tested at two locations (Ames and Vincent) in Iowa. Averaged across locations, none of the ...


Renewed Interest In Foliar Fungicide Use On Field Crops, Laura E. Sweets Dec 2004

Renewed Interest In Foliar Fungicide Use On Field Crops, Laura E. Sweets

Proceedings of the Integrated Crop Management Conference

Although the use of chemicals or fungicides to control plant diseases can be traced back as far as 1000 B.C., it was not until the 1930's- 1960's that substantial efforts were devoted to the development of non-corrosive and non-phytotoxic fungicides. Among the first of the "modern" fungicides were the dithiocarbamate fungicides such as thiram, maneb, and zineb. These materials have broad-spectrum activity but are contact, protectant fungicides. Dithiocarbamate fungicides were used for control of field crop diseases and there still are several formulations labeled for use on field crops. Their use has declined because they are protectants ...


Ecology And Management Of Diseases Of Soybean That Occurred In Iowa During The 2004 Season. Part Ii: Stem And Root Diseases, Alison Robertson, X. B. Yang Dec 2004

Ecology And Management Of Diseases Of Soybean That Occurred In Iowa During The 2004 Season. Part Ii: Stem And Root Diseases, Alison Robertson, X. B. Yang

Proceedings of the Integrated Crop Management Conference

The 2004 season growing season had cooler than normal temperatures associated with frequent rainfalls. The weather conditions were favorable for the occurrence of many soybean diseases. This season, we saw the worst ever outbreaks of white mold and sudden death syndrome, which resulted in considerable damage for many soybean producers. Both diseases were reported in two-to-three weeks earlier in the growing season than usual. Severe white mold outbreaks were found in eastern Iowa, especially from Interstate 80 north. Our quick-and-dirty survey indicates about 20% of soybean fields were affected with white mold in that region, and some fields were up ...


Helping Your Livestock Clients Meet Dnr's New Mmp And Phosphorus Requirements, Jeremy Klatt Dec 2004

Helping Your Livestock Clients Meet Dnr's New Mmp And Phosphorus Requirements, Jeremy Klatt

Proceedings of the Integrated Crop Management Conference

The DNR recently revised its manure management plan (MMP) content requirements to implement the phosphorus (P) index for determination of application rates as required by Iowa law. This presentation will help you assist your clients who are required by state law to have an MMP confinement animal feeding operations with more than 500 animal units.


Managing Scn With Resistant Soybean Varieties: It's Not Just About This Year's Yield, Greg Tylka Dec 2004

Managing Scn With Resistant Soybean Varieties: It's Not Just About This Year's Yield, Greg Tylka

Proceedings of the Integrated Crop Management Conference

Soybean cyst nematode (SeN), Heterodera glycines, is a widespread pest of soybeans in Iowa. The nematode is estimated to be present in three out of every four fields in Iowa (Workneh et al., 1999). The nematode is a serious threat to soybean production because it reproduces very quickly, survives in the soil for many years in the absence of a soybean crop, and can cause substantial yield losses, particularly in dry years. Resistance is a very effective strategy for managing SeN, producing acceptable yields yet suppressing reproduction of the nematode. The number of soybean varieties with genetic resistance to SeN ...


Iowa: Viticulture (Grapes) 101, Michael L. White Dec 2004

Iowa: Viticulture (Grapes) 101, Michael L. White

Proceedings of the Integrated Crop Management Conference

Iowa has a rich and long history of grape production. Grapes were grown in the Council Bluffs area as early as 1857. In 1900 the US Agriculture Census showed that Iowa produced 7,403,900 pounds of grapes and 76,301 gallons of farm-processed wine. Iowa ranked sixth in grape production in 1919 in the United States with more that 12 million pounds. Iowa grape production peaked in 1929 with a yield of 15.8 million pounds. The 1997 Census of Agriculture listed only 56,536 pounds of grapes harvested.


Iowa's Plans And Preparations For The Possible Arrival Of Asian Soybean Rust In 2005, Greg Tylka, Alison Robertson Dec 2004

Iowa's Plans And Preparations For The Possible Arrival Of Asian Soybean Rust In 2005, Greg Tylka, Alison Robertson

Proceedings of the Integrated Crop Management Conference

Asian soybean rust, caused by the fungus Phakopsora pachyrhizi, can seriously reduce soybean yields and/or significantly increase the cost of soybean production when the disease occurs with high incidence and severity Until most recently, the continental United States was the only major soybean-producing area of the world where the disease was not known to exist. But on November 10, 2004, all that changed. On that date, the United States Department of Agriculture (USDA) and subsequently the Iowa Department of Agriculture and Land Stewardship announced that Asian soybean rust had been confirmed near Baton Rouge, Louisiana. The fields where the ...


Fertilizer Application: Nh, Opener Losses And Uniformity Issues, H. Mark Hanna, Paul M. Boyd, James L. Baker, Thomas S. Colvin Dec 2004

Fertilizer Application: Nh, Opener Losses And Uniformity Issues, H. Mark Hanna, Paul M. Boyd, James L. Baker, Thomas S. Colvin

Proceedings of the Integrated Crop Management Conference

Anhydrous ammonia (NH3) is injected below the soil surface during application to limit loss to the atmosphere. Application at a shallower depth may reduce tractor horsepower or allow greater speed which could increase field capacity of equipment if NH3 losses are held to acceptable levels. Losses of NH3 during, and for one hour after, field application were measured from a typical knife injector treatment operated at a 15-cm (6-in.) depth and 8 km/h (5 mi/h) travel speed and from a single-disc injector operated at shallower depths (5 and 10 cm (2 and 4 in.)) and a range of ...


Iowa Edible Bean Production With Direct Marketing To Japan By The Greene Bean Project, Chis Henning, David Ausberger Dec 2004

Iowa Edible Bean Production With Direct Marketing To Japan By The Greene Bean Project, Chis Henning, David Ausberger

Proceedings of the Integrated Crop Management Conference

In January 2001, a group of west-central Iowa farmers and supporters came together to research raising edible beans and other alternative crops. The experiment has grown into the Greene Bean Project, Alternative Crop Enterprises of Iowa, LLC whose members have 1000 acres of alternative crops in 18 Iowa counties. In 2004, the Greene Bean Project farmers produced over 700 acres of azuki (small red edible bean) for export to Japan. This paper will share the cooperatives introduction, progression and issues of azuki production in Iowa and direct marketing to Japan.


Protecting Crop Yields With Postemergence Herbicides, Bob Hartzler Dec 2004

Protecting Crop Yields With Postemergence Herbicides, Bob Hartzler

Proceedings of the Integrated Crop Management Conference

Postemergence herbicides are an important component of today's weed management systems. Herbicides introduced in the past 10 years for use in both corn and soybeans are able to kill much larger weeds than earlier products, thus providing farmers with greater flexibility in application timing. However, this benefit may end up costing farmers money if application is delayed too late into the growing season. This article will discuss the importance of application timing in protecting crop yields.


Rusle2, U.S. Department Of Agriculture Dec 2004

Rusle2, U.S. Department Of Agriculture

Proceedings of the Integrated Crop Management Conference

Released in 2003, the Revised Universal Soil Loss Equation 2 (RUSLE2) estimates soil loss from rill and interrill erosion caused by rainfall on cropland. RUSLE2, like its predecessors, RUSLE and USLE, is used to predict the long-term average rate of rill and interrill erosion for several alternative combinations of crop system and management practice. Lt also considers specified soil types, rainfall patterns, and topography. When these predicted losses are compared with soil loss tolerances, RUSLE2 provides specific guidelines for effective erosion control.


Growing & Marketing Low Linolenic Soybeans - A Value Added Oppportunity, James H. Jensen, Paul Kassel Dec 2004

Growing & Marketing Low Linolenic Soybeans - A Value Added Oppportunity, James H. Jensen, Paul Kassel

Proceedings of the Integrated Crop Management Conference

The Food and Drug Administration's statement that trans-fatty acids are undesirable for human health and the requirement that food processors list trans fats on food nutrition labels beginning in 2006 has poised l% low linolenic soybean oil as part of the solution to the trans fat problem. Unhydrogenated soybean oil does not contain trans fat, but most soybean oil is hydrogenated to increase the shelf life of products that use soybean oil as an ingredient. Low linolenic soybean oil is stable enough without requiring hydrogenation, eliminating trans fat and not increasing saturated fat. According to the United Soybean Board ...


Double Cropping Field Peas After Winter Wheat For Swine Rations, Jim Fawcett, Tom Miller Dec 2004

Double Cropping Field Peas After Winter Wheat For Swine Rations, Jim Fawcett, Tom Miller

Proceedings of the Integrated Crop Management Conference

Most Iowa crop producers now rely on two crops, corn and soybeans, for their livelihood. This has led to many problems, including increased pest problems, such as with bean leaf beetles and soybean aphids, and more vulnerability to adverse weather and poor prices. It has also become increasingly difficult to compete in the world market when these commodities can be produced at a lower cost in other countries, such as Brazil. Crop producers are continually looking for a third crop to include in the rotation, but either the economics are not favorable or there is not a local market for ...


Conservation Tillage System Effects On Soil Productivity And Carbon Credit Incentives., Mahdi Al-Kaisi, Mark Licht Dec 2004

Conservation Tillage System Effects On Soil Productivity And Carbon Credit Incentives., Mahdi Al-Kaisi, Mark Licht

Proceedings of the Integrated Crop Management Conference

Conservation systems play a significant role in improving soil and water quality. Management of crop residue and soil organic matter is of primary importance in maintaining soil productivity and in minimizing agricultural impacts on the environment. Conservation systems utilize tillage practices that are defined by the percent of residue cover left on the soil surface, such as ridge tillage, strip-tillage, and minimum-tillage. These tillage systems and no-tillage each accounted for one-third of Iowa's corn (Zea Mays L) and soybean (Glycine max L Merr.) cropland in production according to a survey conducted by the Iowa Residue Management Partnership (IRMP) in ...


Can We Increase Both, Emerson D. Nafziger Dec 2004

Can We Increase Both, Emerson D. Nafziger

Proceedings of the Integrated Crop Management Conference

The 2002 Farm Bill, price support from increasing industrial usage of corn (primarily ethanol production), and high corn yield and high corn:soybean yield ratio in 2003 have combined to increase corn acreage in Illinois and Iowa. Because corn and soybean occupy such a large percentage of cultivated land in these two states, corn acreage can increase substantially only at the expense of soybean acres, and only by increasing the acreage of corn that follows corn instead of soybean in the crop sequence. Following are some summary points regarding the management of corn following corn:


Crop Weather Cycles: Myth Or Reality?, Elwynn Taylor Dec 2004

Crop Weather Cycles: Myth Or Reality?, Elwynn Taylor

Proceedings of the Integrated Crop Management Conference

Serious Corn Belt drought has followed an apparent 19-year cycle for 200 years. What is the risk of severe drought during the coming six years (2005-2010)? The climate is changing and will likely continue to do so, but will this change the size and suitability of the Midwest as far as Corn and Soybean production is concerned? The cycle suggests that risk of drought is greater during the next 6 years (2005-2010) than it was during the past 12, and history shows that the years of reduced yields seem to appear suddenly just when new record highs are being realized ...