Hulless barley research and development is now receiving more emphasis with potential for feed, food, and industrial uses. Market opportunities, either on the producer's own farm or for sale into the feed or food industry, should be established prior to planting. Variety selection is and will become more important as the various industries demand specific characteristics. In terms of cultural practices, hulless barley should be treated like regular barley except for special care at seeding and combining.
Selecting a Field
If you are planting hulless barley for a market that does not want any hulled kernels, avoid fields where there may be a problem of volunteer hulled barley. Also check your cropping history to avoid fields where there may be a buildup of barley diseases.
When buying seed check the sample very carefully to see that the exposed embryo is not damaged. One way to avoid damaging the embryo is to leave a high percentage of hulls on during combining. Additional hulls will come off during the many handling steps between the combine and the seeder. Thus a good hulless barley seed lot may have a number of kernels with hulls. Be sure to check that the seed lot is not contaminated with regular hulled barley seed. A germination test will reveal the number of damaged kernels. If doing your own germination test be sure each sprouted seed has both rootlets and shoots to be considered viable.
Use Certified seed. Using pure, clean seed of high germination is always a good management decision.
A detailed description of hulless barley varieties can be found in the most recent edition of the Varieties of Grain Crops. At present there are two major types of hulless barley, normal and waxy. The normal type has the traditional ratio of amylose to amylopectin starch fractions as found in regular barley. The waxy type has a very high percentage of amylopectin starch. Markets for waxy barley are being developed.
Hulless barley has an exposed embryo. Some embryos will be damaged before the seed is planted reducing the germination percentage. Hulless barley with germination under 90 % is not uncommon. Therefore, the seeding rate must be adjusted for per cent germination.
Hulless barley has smaller kernels than comparable hulled barley. Therefore, the seeding rate must be adjusted not only for soil conditions and per cent germination but also for seed size to achieve the desired plant population.
Note: the bushel weight for hulless barley (55 -60 lb/bus) is similar to that of spring wheat.
An ideal population is 20 - 24 plants per square foot. For example; if the germination is 90 % and you expect 5 % of the plants not to emerge for one reason or another (this is called field mortality) you need to plant 24 plus 15 % more seeds, which is 28 seeds per square foot. Hulless barley also tends to flow faster than regular barley through seeder metering systems. This requires additional calibration of the seeding equipment.
For best results, sow mid-early May as for other barley.
Place the seed at a depth of 1 ½ to 2 ½ inches in contact with moist soil. Deep seeding will reduce yield.
Use a soil test to determine which soil nutrients may limit growth and the amount of each nutrient needed to correct the deficiency for various soil moisture levels. Fertilizer requirements are the same as those for regular feed barley production. Excessive amounts of nitrogen should be avoided to minimize lodging.
Weed control practices for hulless barley are the same as those for hulled barley. Consult the most recent copy of the Guide to Crop Protection. Assess each field for weeds and plan your weed control accordingly. Always read and follow label directions.
- For seed - Hulless barley intended for use as seed should be threshed gently leaving a percentage of unthreshed kernels. Operate augers at full capacity and at slower speeds to prevent damage to the embryo. You then have to explain to your customers why you left the hulls on.
- For feed - Samples for the Standard C.W. grade (feed) must not have more than 15 % hulls left on. More than 15 % hulls may result in a price discount. When combining aim for 15 % or less hulls left on without cracking.
- For food - The food market (Select grade) requires 5 % or less hulls left on. This target is difficult to achieve during combining. A better alternative is to combine the select hulless barley aiming at a maximum of 15 % hulls left on (just in case your hulless barley is not purchased as select) and buffing the grain to remove the hulls before shipping into the food or specialty market. Similar to malt barley the highest quality of grain is achieved by swathing at lower moisture content or by straight combining.
- Combine adjustment - Standard cylinder combines with blanks installed have been used to produce clean samples of hulless barley. Cylinder speed adjustment will be necessary. Also reduce the clearance at the front of the concave. This setting will reduce the feed rate so you have to drive more slowly. Experienced operators keep an eye on the grain tank, watching for hulls remaining on and for cracking, and make adjustments throughout the day.
A reading of 14.8 % or less kernel moisture is considered dry using the "hulless barley moisture table" for the model 919/3.5 moisture meter. The food market requires a moisture content of 14.5 % or less.
Swine and Poultry Feeds
The removal of the hull is expected to result in modest increases in absolute nutrient levels of hulless as compared to regular barley. In practice, the nutrient composition of hulless barley often exceeds this expectation. This is why there is a growing interest in developing hulless barley for the feed industry.
The following are some of the benefits of hulless barley:
- Increased crude protein - The crude protein of hulless barley typically exceeds that of comparable hulled types and should be 1 to 2 % greater.
- Improved digestibility - Studies have demonstrated that available energy is higher than hulled barley and is closer to that of wheat. A trend to improved digestibility has been reported. For poultry, the use of enzymatic feed supplements improves the digestibility of all barley including hulless types.
A word of caution when using hulless waxy barley or blends of barley containing waxy barley. Waxy barley is generally high in beta-glucans so enzymes should be considered when feeding to swine. Waxy barley or blends containing waxy barley should be avoided for poultry feeds.
- Less manure - A major fraction of manure is fibre, and relatively small differences in dietary fibre may result in considerable changes in manure output. Reduced manure means reduced manure handling and disposal. This is important where human population and animal production are in close proximity. Also, fewer hulls make liquid manure handling systems more effective.
- Less handling and storage - Hulless barley has a major advantage over conventional barley in transportation, processing, and storage. Removing the hull fraction increases the bulk density (weight-per-unit volume) compared to conventional barley by about 25 percent. The increase in bulk density depends on the amount of hull left on. Cost savings can be considerable.
- Less fines during processing and handling - There is some indication that hulless barley produces less fines during processing and handling than wheat. Poultry and swine do not like fines.
There is a growing interest from food processors for hulless barley. Some examples of food uses are:
- addition to ready-to-eat breakfast cereals,
- rice like products (after splitting and polishing),
- thickeners, and;
- health foods, etc.
The Canadian grading system now has a recognized grade for the food market. This helps companies get the quality they need.
Prepared with assistance from the Crop Development Centre, University of Saskatchewan.