HEADER HARVESTERS

Ellesmere Guardian, Volume 66, Issue 98, 12 December 1944, Page 2

HEADER HARVESTERS

THRESHING SMALL SEEDS

HOW TO AVOID LOSSES

The losses in small seeds and in their commercial value by faulty threshing is the subject discussed in the December Agricultural Bulletin. This is a most timely article as the season for harvesting small seeds will soon begin in the Ellesmere and surrounding counties. The bulletin has been prepared by the Canterbury Agricultural College and published by the Canterbury Chamber of Commerce. The text is as follows:

Introduction In this bulletin methods of avoiding losses due to skinning and cracking of seeds in threshing will be considered. An appreciation of the very great value of the seed business to New Zealand generally can be obtained from the following figures showing the increase in quantities and values of grass and. clover seed exported over recent | years.

This table shows an increase from under one third of a million pounds to almost one million pounds. Farmers are nowadays making a business of seed growing and not as in the past years merely saving occasionally surplus grass and clover for seed as a catch crop. The export of seeds from New Zealand has been given a great impetus over the war years — due chiefly to the fact that out best customers, United Kingdom and Australia —- have not been able to secure supplies from other European countries, and have had to rely upon New Zealand for their supplies of ryegrass, cocksfoot, white clover, etc. Normally these varieties can be obtained from Denmark, France, Poland and other European countries, and we in New Zealand have had to compete on a price basis with these countries. The time is not far distant When these countries will again be competing with us for the United Kingdom market, and it behoves New Zealand farmers and merchants to see that no opportunity is lost to hold what we have gained over the past few years. We can produce the finest seed in the world—both in strain and quality.

I The advent of header harvester i machinery has brought about many [Problems and farmers have much to .learn about the, use of them. Damage caused 'by inexperienced handling of these machines is particularly serious in the case of red clover and ryegrass seed. Inefficient adjustment results in a big loss due to cracked and broken seeds. This damage is reflected in the decreased value of the seed, and in many cases it prohibits export. Farmers should realise that cracked and broken seeds cannot be, dressed-out on seed dressing plants and in the years to come lines containing damaged seed are likely to be difficult to sell. More and more the tendency is for merchants to buy seed on a machine dressed basis and subject to a purity and germination test. Lines of seed which do not measure up to the normal export standard — in most cases 98 per cent and 90 per cent germination — will be unsaleable in years of low export demand. It is hoped that there will continue to be a big demand for New Zealand seeds overseas, but to ensure this the seed must be of the highest strain and grade. This is primarily a matter for the grower—to see that he has the best strain available and gets it into the bag in the best possible condition. An example of the losses that occur is shown by the facts set out m a report issued by the Seed Testing Station, Department of Agriculture, Palmerston North. For the 1943-44 harvest 20 per cent of the total samples of Montgomery red clover failed to conform to the 98 per cent purity standard, by reason of broken seed content; and 30 per cent of the total samples failed to comply with the minimum trade germination standard of 90 per cent, by reason of the abnormal seedlings produced from the broken and cracked grains. Further in many seeds internal fractures are produced which are not visible but which result in the seedlings being bruised. Some of these seeds may germinate while fresh but they have not the vitality to produce a plant under field conditions. These figures show startling results from bad handling in the case of Montgomery red clover, but similar injury may occur in the case of barley, wheat, peas and ryegrass, etc. Damage may result to peas if they are £ IS<SL trough threshing when too soft The farmer often cuts the crop on the green side to obtain a good colour. Bleached peas are always at a discount on the market, especially blue peas which are used for human consumption. These crops must be cut green but allowed to dry thor-

oughly before threshing. Damage to white clover seed does not normally occur but great damage to ryegrass may occur where attempts are made to thresh out white clover and ryegrass in the one operation. | Reduction of Losses Damage may be reduced or avoided by paying stricter attention to the condition of the material when threshing, and to the adjustment of the threshing machine. Condition of Material When Threshing The crop should be allowed to dry out before threshing is begun. This object will be more easily achieved if the crop is cut after it has reached as near maturity as possible and if sufficient time is allowed between cutting and threshing. In the case of direct heading, the crop should be allowed to get dead ripe before threshing. When the material is threshed out of condition the seed is soft and easily bruised, resulting in damaged seed. Further, it is essential that threshing should not* be commenced too early in the morning and should cease the moment the material toughens up towards evening. When the crop is windrowed an attempt must be made to lay a windrow that permits of even drying and is therefore not too thick in any one position but yet not laid so thinly at to involve risk of loss of seed. The laying of suitable windrows can be assisted by the use of an inside and outside divider board on the mower, or by attaching a spreader bar to the table of the binder. Seed loss can be reduced to a minimum if the heads are laid up on top of the previous straw butts in a scalelike manner. The angle" at which the windrow is laid should depend on the type of pick-up attachment and the direction of feed to the drum. The minimum cracking will be involved where the material has been laid in a thick bulk where the heads are fed direct into the drum. To avoid bruising it is. necessary to have an evenly distributed flow into the drum. It may be necessary under certain conditions to use a windrow spreader on the header. A uniformly dry swath is the ideal but ig possible only with a mechanical method of lifting from undergrowth or damp ground. Drying may be assisted by mowing under the windrow or by raising up the windrow from the undergrowth by using a special swath pick-up and aerator prior to picking up again for threshing. Experimental trials last season showed that it is now possible to lift a swath mechanically from a new growth or from damp ground conditions. Within a few hours under suitable conditions of sunshine and wind, threshing can begin always provided the crop itself is fit. Adjustment of the Threshing Machine To avoid cracking and bruising, five main adjustments to the header require continuous attention: (1) The number of concave bars should be reduced where removable to the minimum necessary to thresh. In the case of the peg drum machine the number of pegs should also be reduced to the minimum possible while still separating out the seed.

(2) The clearance between the drum and concave should be as wide as possible while still ensuring the threshing out of the seed. (3) The drum speed should be reduced to the minimum speed that will still give clean threshing. Under changing atmospheric conditions it will be found necessary to vary the settings and drum speed throughout the day. If adequate adjustment is not possible it is better to cease threshing until conditions are satisfactory.

(4) A further cause of damage may- be due to excessive return of seed to the drum, so that much of the seed may be threshed two or more times. The liability to loss here can be reduced by threshing only when the material is in good order, by proper adjustment of the drum, spacings and speed and also by proper adjustment, of the blast and riddles. The blast should be so regulated as to blow out all light cavings.

(5) The riddles should be opened as widely as possible, or as large a size of riddle as possible used, or even the riddle removed so as to avoid all unnecessary return of seed to the drum. Subsequent dressing may be necessary and it is preferable to leave some of the unnecessary material rather than risk damage to the seed by close setting or

use of small riddles. Summary of Recommendations To obtain purity and germination, sufficient to gain the highest certificates, the following precautions should be taken:— (1) General: "The minimum that can be done to extract the maximum of good seed, gives the best final result" . . . because, (a) If seed is threshed too hard broken growths cr bruised seed is the . result, (b) Once the wings or tails of weed seeds such as hair and goose grass are broken it is almost impossible for cleaning plants to obtain purity and germination standards. Weed seeds as well as main crop seeds must be left, then they can be dealt wh^h by up-to-date seed cleaning machinery. Do not try to make a machine dressed sample on the header. Nature has so fashioned her seeds that there is a reasonable chance of separating them if they ,are left in their natural state. (2) Ryegrass. Damaged seeds are largely the result of — (a) Too high drum speed. (b) Concave too close. (c) Too great a return to the drum through the tailing elevator — caused by too small a finishing riddle or adjustable riddle closed too much. (3) Mixed ryegrass and white clover: If good certified ryegrass is wanted do not try to shell the white clover while harvesting. A modern N.Z. built dressing plant wiU extract the grass seed from the unshelled clover and unbroken weeds. This gives the maximum quality ryegrass. The unshelled clover and weed seeds can then be satisfactorily treated and all the clover can be extracted also. (4) Italian ryegrass: All the above factors apply, but of most importance is the necessity to preserve the tail by the utmost care in the above adjustments. (5) Cocksfoot: This seed may be threshed harder than ryegrass. Care is required not to shell the seed or to break the straw. (6) Clovers: These crops should not be threshed from windrows uni til they are thoroughly dry and have had the maximum benefit from I sun and wind. On no account should

they be threshed on a dull or damp day. Under these conditions some of the top of the windrow may be dry and hard, but the bottom will contain soft and easily damaged seed. If the windrow is lifted this will assist uniform drying. If some seed is left in the cob this can be satisfactorily treated by modern seed dressing machinery. Damage and loss is largely caused through trying to thresh clover from the cob when the crop has been too recently cut and not sufficiently weathered. Necessity for Skilled Operators At some future date it may be practicable for those operating headers to attend- short courses in header operation and adjustment at Lincoln College and obtain a certificate of proficiency in this important work. At present some contractors have a tendency to put the job through without regard to the quality of the seed threshed. It is difficult for farmers to check this even after they have realised the damage likely to result as under existing conditions the contractor may leave the job and go to the next. It would assist to improve matters if it were possible to organise payment of contractors on the results achieved. Montgomery red clover, of which by far the greatest proportion is header harvested, is a late maturing crop and

not usually ready for .harvesting before late March or April. At that time of the year even on clear days, morning mists and evening dews narrow down satisfactory header operation to four or five * midday hours: The farmer with one eye on the weather and the contractor harvester with his mind on crops still to head are both tempted to exceed the optimum hours. When the seed fails to shell—nature's indication to stop trying—the tendency is to screw up the machine another notch and carry on. This . is when the damage is done. The seed itself is dry and brittle but the cob has become tough and even though the damage is not apparent the seed has cracked beneath the skin although seemingly still whole. It is not until the. germination reports come back from the seed testing station that the sad story is - told. Such seed is diflScult .to'sell'-'-JJ--on the overseas market and may <J y £ have to be sold in the local market at a big discount. Conclusion The damage caused by faulty threshing can be very great and cannot be remedied by machine dressing, as most of the chipped seeds and all of the cracked and bruised seeds remain in the dressed line. Under methods of testing prescribed by the International Testing Association cracked and broken seed is classed as inert matter—an impurity. The presence of over 2 per cent of impurities means that the purity of the whole line falls below 98 per* cent—the minimum percentage of purity required for first class standard export seed. Twenty per cent of tbe total red clover 1943-44 lines fell below this standard by reason of broken seed content alone. Broken growths are abnormal seedlings produced by apparently normal seeds the embryos of which have been partially ,or completely / fractured. *This injury renders the seedling incapable of establishment in soil. The percentage of germination required for first class standard export seed is a minimum of 90 per cent. X Thirty per cent of the total 1943-^ 44 lines fell below this standard by reason of broken growf_ts from damaged seed. Losses can he reduced by strict and continuing attention to the foregoing suggestions regarding care m harvesting. Other Bulletins that may provide useful information on this subject are No. 137, Harvesting of Small Seeds, No. 161, Quality in Pasture Seeds, No. 149, Operation of the Header Harvester, and No. 150, Adjustment of Header Harvester for Various Crops.

Exports of Grass and Clover Seed Cwt. Value Seasons (1000) ' (£1000) 1939-40 40 £324 1940-41 58 £402 1941-42 99 £661 1942-43 62 £427 1943-44 106 £915