Barley Must Be Fit For Threshing

Press, Volume XCIX, Issue 29104, 16 January 1960, Page 8

Barley Must Be Fit For Threshing

Barley is an easy crop to thresh if grain and straw are in fit condition, says Mr J. P. Malcolm, field officer of the Canterbury (N.Z.) Malting Company, Ltd., in a Canterbury Chamber of Commerce agricultural bulletin. More than two-thirds of the crops in Canterbury are direct headed and the remainder are picked up and threshed from the windrow. Direct heading is the safer method in a crop free from green weed growth and ripening evenly. After rain a standing crop will dry out much faster than a windrow and the chances of sprouting are greatly reduced. Wind damage in mature standing crops occurs infrequently enough to make the risk worth-while in relation to saving expense and convenience. Before threshing is begun the grain should be hard or “snappy” when bitten or cut with a knife. Patience for an extra day may be well rewarded if threshing is facilitated and the hard labour of turning high moisture grain in the paddock is obviated. The header harvester must be set to make a clean job the first time the straw passes through the drum and concaves. If this is not done then partly-threshed barley will return through the drum a second time increasing, the chances of damage by skinning. The first adjustment to make if grain is being skinned is to avoid grain return by opening the adjustable sieves and increasing the blast. However, the most important adjustment to correct skinning damage is to reduce drum speed considerably. Clean threshing • is then achieved by correct drumconcave clearance. Under certain circumstances the clearance can be as close as possible providing the drum speed is slow. An extreme setting of this nature can be described as a pea drum-speed and clover clearance between drum and concaves. The mechanical action Is a slow, hard, rubbing action rather than a fast, hitting action.

Barley is often threshed too hard when an attempt is made to recover every single grain from the straw. Often the amount of grain left in the straw is exaggerated in terms of total loss. It must be remembered that one bushel per acre loss through the header means eight complete heads (or 200 grains) in a running yard of straw on a six foot cut. This quantity is rarely seen, but how often has it been estimated as five or 10 times this amount in terms of bushels per acre? The problem in removing screenings is difficult to solve under field conditions. Practical threshing rates of headers are usually far higher than their screening capacities. For malting barley anything including and below 15 per cent, screenings is accepted and receives a fair price according to grading. A crop containing well above 15 per cent, screenings may be considered a failure from a malting point of view.