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Volume 10, Number 6 - June 2004

This Month in Ag Connection

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High-Tech Compaction Measurement May Be Subject To Misinterpretation

Soil compaction, "the silent thief" of crop yields, is often blamed when crops are struggling for no obvious reason. It is easy to blame soil compaction, but it's also difficult to quantify compaction. You can't see it, count it, or put a number on it just by digging.


Some producers are turning to soil penetrometers as a way to measure compaction. The device provides a quick reading of the force required to push the cone-shaped tip of the penetrometer into the soil.

Unfortunately, the readings from a penetrometer are too easily misinterpreted. The latest fad is to take penetrometer readings and index them with GPS coordinates to make a colored map. In some cases, the map turns out to indicate severe soil compaction all across the field. Under other soil-moisture conditions, that map might be different.

Soil penetrometers have valid uses but producers need to be cautious about the decisions they make from any one type of soil physical property measurement. Based only on penetrometer readings, producers might believe compaction in their fields is far worse than it really is. Producers may be too quick to rip their fields and unnecessary ripping may do more harm than good.

Focus instead on productivity and the bottom line. If you are sure you want to rip, Bill Casaday, MU Extension Ag. Engineer, will help you set up a statistically valid test to determine whether ripping pays under your particular set of circumstances and for your particular soil type.

(Author: Bill Casaday, MU Extension Ag. Engineer)

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What Is All The Concern With And What Is Soybean Rust?

While soybean rust has not been reported in the continental United States, it is a matter of when and not if it will arrive. Soybean rust was first reported in the Eastern Hemisphere in the early 1900s. Over the next 50 years, the disease became established from Japan to Australia, westward to India, China, and central and southern Africa. In the western hemisphere, soybean rust has been reported in Latin America, regions of the Caribbean, Puerto Rico and Hawaii. Soybean rust appeared in Paraguay in 2001 and it then spread through Argentina and Brazil in 2002.

In countries in which soybean rust is an established problem, losses range from 10 - 80 percent. The severity of losses varies depending on variety, time of growing season in which the rust becomes established and weather conditions in the growing season.

The soybean rust fungus has several characteristics that make it a serious pathogen. The soybean rust produces a large number of spores on infected plants. Wind currents and storms readily spread the spores. Also, the soybean rust pathogen has many crop and weed hosts. Over 30 species in 17 genera of legumes can be hosts of this fungus. Among the hosts of soybean rust that are found in the United States are kudzu, yellow sweet clover, medic, vetch, lupine, green and kidney beans, lima or butter bean and cowpea or black-eyed pea.

Soybean varieties grown in the United States have little or no resistance to soybean rust. Rust pathogens are considered to be obligate parasites, i.e. they survive on living plant material. Although the soybean rust may not be able to overwinter in central or northern soybean production areas of the United States, it may be able to survive winter months on hosts such as kudzu in the southern United States. Soybean rust spores could then be carried north on wind currents and by storms just as wheat stem rust, wheat leaf rust and corn rust are now.

It is now accepted that there are two different fungal species that cause soybean rust. Phakopsora pachyrhiza, referred to as the Asian or Australian soybean rust, is the more aggressive pathogen and was primarily established in the Eastern Hemisphere. Phakopsora methomiae, referred to as the New World type, is a much weaker pathogen and is the pathogen that had been common throughout the Caribbean and Central and South America. Unfortunately, it is the Phakopsora pachyrhizi that has been spreading through soybean producing regions of the world and it is the most likely one to affect soybean production in the continental United States. The two types of rust cannot be distinguished by foliar symptoms in the field making a lab analysis necessary.

The most common symptom of soybean rust is a foliar lesion. Soybean plants are susceptible to soybean rust at any stage of development, but symptoms are most common from flowering on. Lesions range in color from gray-green to tan, dark brown or reddish-brown. The lesions tend to be blister-like pustules, angular in shape bound by the leaf veins. These pustules are up to a quarter of an inch in diameter and are most evident on the lower leaf surface, but can also develop on petioles, pods and stems. At this stage soybean rust might be mistaken for bacterial pustule or bacterial blight. As the rust pustules mature, they begin to produce large numbers of powdery spores. Rust pustules are most common on the underside of leaves but may also develop on petioles, pods and stems. Leaves may yellow and drop prematurely.

Yield losses are due to a reduction of photosynthetic area on the plants and the resulting reduction in pod and seed numbers and in seed weight. Soybean rust is usually found first on the lower leaves of plants from flowering on. As the plants mature, lesions may be found in the middle and upper canopy of the plants. When conditions are favorable for disease development, yellowing of the foliage may be quite evident, and defoliation and premature death of plants may occur. Soybean rust development is favored by prolonged periods of leaf wetness and mean daily temperatures of less than 82 degrees F. Extended periods of cool, wet weather during the growing season would favor soybean rust epidemics.

In countries in which soybean rust is an established problem, management is through the use of resistant varieties and foliar fungicides applied during the growing season. Two to three fungicide applications may be necessary depending on disease activity.

For more information:

Some information for this article was provided by Laura Sweets.

(Author: Wayne Crook, Agronomy Specialist)

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Fire Extinguisher Selection And Use

Fire extinguishers are classified by the types of materials involved in a fire. You should look for the UL or FM seal of approval on fire extinguishers. The following are the classifications:

Fire Extinguisher

For general farm and home use, it is suggested you purchase a multipurpose extinguisher with an A, B, C classification. The size of the extinguisher is also a consideration in selection. The larger the size does not always mean the extinguisher will put out a larger fire. It may vary by the type of extinguishing material. Lower priced extinguishers may not be capable of being re-charged.

Fire extinguishers are effective only on small fires in the initial stages. Don't risk your life to fight a fire. Have a plan of action:

It is also important to learn how to use an extinguisher. Read the operating instructions and if possible practice on a fire and then have the extinguisher re-charged. You should always recharge them after use even if they have not been completely used.

Fire extinguishers should be inspected at least annually. Materials in fire extinguishers have a tendency to settle. You should shake the fire extinguisher periodically to loosen the materials.

Extinguishers come with a bracket for installation. They should be installed away from any potential fire hazards and near exits or escape routes.

For more information see the following web sites:

(Author: Don Day, Natural Resource Engineer)

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Taxation Tidbit: Delayed Like-Kind Exchanges

Tax rates on long-term capital are at a historically low-rate. Still, tax on capital gains can present a stumbling block for individuals desiring to realign their business, trade, or investment assets. Code Section 1031, an asset exchange provision, is a tool that can provide for the tax-free realignment of these types of assets.

For example, you have 300 acres of farmland acquired for $100,000 many years ago is now worth $600,000. Section 1031 provides a method of selling this property and deferring the recognition of the $500,000 gain - if the $600,000 from the relinquished property is reinvested in like-kind replacement property within 180 days. This procedure is known as a delayed like-kind exchange.

For real estate, the definition of like-kind property is very liberal. Like-kind real estate means any improved or unimproved real estate held for income, investment, or business use. Improved real estate can be replaced with unimproved real estate, and vice versa. Additionally, one property can be replaced by two or more properties, and vice versa.

Section 1031 is a "big gun" in the hands of a tax planner. While I would not classify the deferred exchange of like-kind property as an aggressive tax strategy, it is a strategy that must be carried out with timeliness and exactness. Thus, if this is a strategy you would like to utilize, get your tax professional involved in the planning process as early as possible.

  1. An "intermediary agent" must be utilized to hold the sale proceeds during the replacement period.
  2. Replacement property must be "identified" to the intermediary agent within 45 days of closing on the exchanged property.
  3. The replacement property must be acquired, i.e. closed, within 180 days of closing on the exchanged property.
  4. "Boot received" will always result in recognition of gain, the lesser of the boot received or the total gain. Avoid recognition of any gain by acquiring replacement property at a price equal to or greater than the sale amount of the exchanged property.

Other types of Section 1031 exchanges you may want to investigate:

(Author: Parman R. Green, Ag Business Management Specialist)

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Publishing Information

Ag Connection is published monthly for Central Missouri Region producers and is supported by University of Missouri Extension, the Commercial Agriculture program, the Missouri Agricultural Experiment Station and the MU College of Agriculture, Food and Natural Resources. Managing Editor: Kent Shannon.