ISSUE 15 August 10, 2000
Flax acreage continued to increase in North Dakota in 2000 with 525,000 acres expected to be harvested. A number of new producers have called requesting the proper time to cut and harvest flax.
Flax is ripe when 90 percent or more of the bolls have turned brown
and can be combined direct Any green bolls remaining will crush and pass right through the
combine. Direct combining is the cheaper method and is entirely satisfactory when the flax
is thoroughly dry and free of weeds. However, the most common method of harvest is with
the swather and windrow pickup attachment on a combine because few fields are free of
weeds and few ripen uniformly. Flax is considered to be fully mature
when 75% of the bolls have turned brown. After this stage has been reached, the crop may be swathed. If regrowth occurs in the fall, cut the crop when the greatest amount of ripe seed can be obtained. Do not delay the harvest too long because fall rains may cause weathering of the mature seed and frost may cause immature seed to turn black, resulting in a reduction in grade. Swathed flax is in condition to combine after a few days of dry weather. Swath rollers are often used to pack the windrow to prevent destruction or movement by wind. When swathing, leave a stubble height of about 4 to 6 inches to hold the
flax swath off the ground for good air movement and drying.
Considerable frost damage occurs in immature seeds when temperatures drop to the 27 to 23F range, while leaves are severely damaged at 25 to 23F and stems at 21 to 19F. Cutting or desiccating flax at an immature stage is not known to result in seed blackening, but yields will be reduced due to early termination of seed development. This will result in thin seeds of lower test weight.
Chemical desiccation may be used to accelerate drying of the crop and any weeds that may be present. It does not speed crop maturity, but will reduce the time from maturity to harvest. Potential advantages from this practice are:
- earlier harvesting;
- elimination of the need for swathing;
- reduction in combining time;
- less wear and tear on machinery;
- cleaner seed;
- reduction or elimination of the need for artificial drying.
A desiccant may be applied after 75% of the bolls have turned brown, which is the normal time of swathing.
In North Dakota, Defol (sodium chlorate) and Roundup Ultra (an emergency label this year) can both be used for weed desiccation. To use Roundup, the applicator must read and have the emergency label in his possession.
Studies at Morden, Manitoba by Ag Canada researchers, have shown that yields are reduced if applications are made too early. For instance, swathing or desiccating at the 25 to 50% brown boll stages, reduced yields by an average of about 10% and 5% respectively, due to premature termination of development of some of the seed.
Desiccated flax should be harvested as soon as possible after it is ready, to avoid boll loss and weathering of the seed.
Flax should be stored at 10 percent moisture or less for safe storage. For long-term storage 8 percent moisture is suggested.
CROP RISK MANAGEMENT INFORMATION
Introduction to Risk Management: Understanding Agricultural Risks. A
handbook is available from USDAs Risk Management Agency that helps producers assess
risk management by focusing on five primary sources of risk: production, marketing,
finance, legal and human resources. Available free online in Acrobat Reader 3.0 and higher
PDF format thru website:
To request a hard copy, write to: FSA-KCMO Warehouse, 9420 Troost, Kansas City, MO 64131-3055 or fax your request to: 1-816-363-1762. Many other reports and publications are available at this site from the Risk Management Agency. Among them are: Building a Risk Management Plan: Risk Reducing Ideas that Work, 2000 Revenue Crop Insurance plans, and 1999 Report to Congress: New and Specialty Crops.
Anyone who works with and provides advice to crop producers should be fully aware of risk management strategies to increase profitability and reducing risks if at all possible.
Duane R. Berglund
CONNECT WITH THE FUTURE USING CROP RESIDUE
Erasing erosion is almost impossible once the problem develops out in fields. This is why some Kansas and Indiana USDA researchers are working to prove that standing crop residue is good for erosion control before the erosion evidence shows. Current estimates show that erosion removes more than two billion tons of soil from U.S. cropland annually. Left standing, residue can be ten times more effective at reducing erosion than if the residue were chopped or tilled. In order to determine just how much residue contributes to erosion prevention, you have to measure the amount of residue in the field. Old estimates by picture references are out, in are estimates by laser scanners.
Using a research laser scanner (combination of a 35mm camera why not
digital and a low-power laser beam), the researchers detect then measure the standing
residue. The scanner has a range of 10 inches to 15 feet with the optics mounted on rail
for row measurements or on a turntable to measure residue in a 10-foot circle (such as for
solid seeding situations). The process for using the stubble scanner is likened to the
process, if you could, of passing a four-meter-long (just over 13 feet) strip of land
through a photocopy machine. The scan makes just one pass with an advancing red line like
a copy machine. Image elevation is measured in thousandths of an inch and scans 3,000
elevation points per second, creating a parameter
profile that is just over 13 feet long and just under 2 feet wide. Soil surface roughness as well as the residue within the scan gives the researchers an idea on the erosion potential. Soil depressions during rainfall, for instance, slow erosion by holding water for a while then, as the depressions fill, they spill into each other, concentrating the runoff and erosion worsens.
Think about the potential if quick scans were possible on a large scale. The idea that has been floating around the last three years on carbon sequestering payments for farmers that conserve residue might be closer to being evaluated and payments based on residue returns. Learn more on residue management before turning over the straw by clicking on other information Web links at:
http://www.oznet.ksu.edu/pr_forage/Map/Map.htm (on grazing residue with field examples from Kansas),
http://wepp.www.ecn.purdue.edu/~wepphtml/wepp/wepptut/part4/manrcs.html (backtrack through this interactive field management program to see the effects of different residues),
http://www.farmshow.ca/farmshow/corninfo/soil3.shtml (more links through the corn connection).
LEFTOVERS LEAVE YOU SMACKING ON SUGARS
You may be hearing a new word in sweeteners soon. Xylitol, a low-calorie sweetener, derived from corn is making news as some makers of specialty brand sugarless chewing gums currently pay three dollars per pound for xylitol, the product that produces the minty-cool taste. USDA research in Illinois is looking to locate the tasty product from corn fiber leftovers.
Right now, corn fiber and fermentation co-products, when used, are sold together as cattle feed for a few pennies per pound. Current sources of xylitol are made in Finland from acid-treated fibers of birch wood by a chemical process that requires high pressure and temperature controls, an expensive catalyst and extensive steps to remove byproducts.
A biotech approach using corn fiber could require less energy and be
cheaper and could allow American farmers to step into the $28 million market in foods for
special dietary uses, mouthwashes, toothpastes as well as chewing gums. Already research
has confirmed one strain of yeast that hydrolyses the corn fiber to release up to 20
percent of the xylose in treated fiber. Since this early discovery, another process has
identified a mixture of enzymes that release up to 70 percent of the xylose from corn
fiber. The xylitol has one-third fewer calories than conventional sugar with about the
same sweetening power and diabetics
can process the sugar without involving insulin and the sweetener also allows harmless bacteria to crowd out common mouth microbes usually associated with tooth decay. Find out more about this crop product and other sweeteners at:
Extension Crop Production Specialist