IMPURE SEED.

New Zealand Journal of Agriculture, Volume 4, Issue 6, 15 June 1912, Page 437

IMPURE SEED.

THE SOURCE OF OUR WEED PROBLEM.

A. H. Cockayne.

Introduction.

©NE of the most serious problems confronting the farmer of this Dominion is the adequate control of noxious weeds. The following is presented in the belief that comparative immunity from many of our worst weeds can be , secured by 'the avoidance of actually sowing them, often quite unwittingly, along with ordinary farm seeds. It also, appears highly desirable to point out the many advantages attendant on the employment of seeds of only the highest grade. - By this means it is hoped to stimulate a more lively appreciation of this-type of. seed as compared with low-grade inferior lines : these are sown, unfortunately only too often, under the totally erroneous conception that being cheaper

in price they must therefore be the more profitable. One of the main objects of this article is to disprove this fallacious idea. It is essential to bring home to the farmer the indisputable fact that the sowing of lowgrade weed-infested seed is not only of immediate and incalculable harm to the user himself, but also forms a very grave menace, to the future prosperity of the whole Dominion.

Noxious Weeds

The term “ noxious weeds ” is generally restricted to those undesirable plants of our flora that the farmer by actual legislation is compelled to suppress, or at least hold under control in some small measure. Many settlers perform only the minimum of work necessary to satisfy the Inspector. Unfortunately they look upon the work incurred merely as a means of avoiding conflict with the law, and not as a means of freeing the land from a serious incubus that is exhausting the resources of the soil. With regard to “ noxious weeds,” a much broader view of the term should be taken ; in fact it should include all those plants whose growth interferes with the yield of the crop or pasture on the soil where they are growing. - At a moderate estimate weeds diminish the annual producing-power of our land by at least .5 per cent. This represents a yearly loss of nearly £1,000,000 sterling on our agricultural exports alone. A good deal of this loss is now almost irremediable in those soils which year after year have carried large numbers of weeds, filling the ground with innumerable seeds that will develop whenever a favourable opportunity arises. Much of the loss can, however, be avoided.

The Origin of our Weed Flora.

The vast majority of our weeds owe their origin to having been actually sown, in most cases quite unintentionally, along with ordinary agricultural seeds. With certain exceptions, such as blackberry, sweet-briar, gorse, and broom, all our weeds which injure crops and pastures can be attributed to this cause. Impure seed can thus be reckoned upon as the greatest factor in the production of our noxious-weeds problem.

The Area laid down in Grass.

Annually large areas of virgin country, in many cases quite free from weeds, are sown with grass and clover seeds. During the past ten years about two million acres have been dealt with in this way. If on this, area only pure seed had been used the weed problem would on it be quite a negligible quantity. The significance of this is apparent.

On a very large proportion of the pasture yearly laid down the first sowing is the only one that can ever be successfully carried out. When this is

considered it can be clearly understood that the future results from such ground depend to a very large extent on the quality of the seed used.

The Necessity for testing.

From the above it can be seen how important it is to ascertain the quality of all seed that is to be used . for sowing. Before purchasing, the farmer should accurately determine what impurities are present in the samples, and those showing any that are likely to cause harm should be rejected.

The necessity for testing seeds before sowing is well recognized in older countries. In most European countries the farmer buys his seed on a written guarantee as to its purity and germination, and if he sows seed containing noxious weeds he has, only himself to blame.

The Desire for Bargains

The desire for “ bargains ” in seed-buying is one that the farmer should sternly repress. It can safely be taken as an axiom that there are no “ bargains ” in the seed trade. The average seed-merchant knows to a nicety the market price of seed of average quality, and he is hardly likely to sell good seed at a price below the-ordinary market rate.

Some examples of so-called cheap seed may not be out of place here. These are taken from actual samples examined during the past year :

White Clover. — The price for a certain line of white clover was Is. Id. per pound. Good white clover could be purchased at the time at Is. 6d. The sample gave a purity of 64 per cent, and a germination of 33 per cent., or a real value of 21 per cent. i.e., in 100 lb. of the sample only 21 lb. consisted of pure white clover capable of growing. Thus over ss. was the price actually paid for lib. of pure white-clover seed. The 34 per cent, of impurities consisted of twenty-three different kinds of weed-seeds present to the number of 230,000 individual seeds to each pound.

Another sample of white clover that was offered below the current market price contained thirty-six different kinds of weed-seeds.

Red Clover. — A line of red clover offered at a very cheap price contained 10 per cent, of impurities, consisting of sixteen different weed-seeds. Amongst these was clover dodder at the rate of over 8,000 seeds per pound. Another sample contained over 20 per cent, of impurities, consisting of twenty-three kinds of plants other than red clover.

Timothy. — The following is an analysis of a line of New. Zealand timothy that was offered for sale : The purity was 94-3 per cent., and 1 lb. of the seed contained the following seeds other than timothy : Ragwort, 41,374 seeds ; Yorkshire fog, 9,513 seeds; mouse-eared chickweed, 9,060 seeds :

Poa pratensis, 2,416 seeds; docks, 453 seeds; sow-thistle, 453 'seeds Californian thistle, 151 seeds : total, 65,420 seeds.

The above examples serve to demonstrate the contention that cheap seed means bad seed, and the use of bad seed is the most expensive policy that any farmer can adopt.

A Knowledge of Seed Impurities important.

There are few farmers who have sufficiently studied the question of weedseed impurities to enable them to tell at a glance the most common weeds likely to be found in agricultural seeds. In order that our farmers and seedmerchants may be provided with a ready means of determining the most common impurities found in agricultural seeds the Department has prepared a neat reference-card, mounted between sheets of glass,” containing the seeds of. fifty of the most common weeds to be found in ordinary commercial samples. Attached to it is a pocket magnifying-glass. , This complete little demonstration guide will be offered at a price which will just cover the cost of preparation.

List of. the Seeds in the Weed-seed Reference-card.

Twitch (Agropyron repens). Goose-grass (Bromus hordeaceus). Hair-grass (Festuca bromoides). Yorkshire fog (Holcus lanatus). Darnel {Lolium temulentum). Buttercup {Ranunculus parviflorus). American cress {Barbarea praecox). Wild turnip {Brassica campestris). Shepherd’s purse {Cdpsella bursa pastoris). Cress {Lepidium ruder ale). Hedge mustard {Sisymbrium officinale). Catch-fly (Silene gallica). Spurrey {Spergula arvensis). Tutsan (Hypericum androsaemum). Cranesbill {Geranium dissectum). Suckling clover {Trifolium minus). Vetch {Vida sativa). Hemlock (Conium maculatum). Wild carrot (Daucus carota). Cleavers {Galium aparine). Yarrow {Achillea millefolium). Chamomile (Anthemis cotula). Spear thistle (Carduus lanceolatus). Californian thistle {Cnicus arvensis). Star thistle {Centaurea cyanus).

Chicory (Cichorium intybus). Hawkweed (Crepis capillaris). Ox-eye daisy {Chrysanthemum leucanthemum. Catsear {Hypochaeris radicata). Nipplewort (Lapsana communis).Hawkbit (Leontodon hispidus). Mayweed (Matricaria inodor a). Ox-tongue (Pieris echioides). Ragwort {Senecio Jacobaea). Sow-thistle (Sonchus oleraceus). Dandelion (Taraxacum officinale). Scarlet pimpernel {Aangallis arvensis). Vipers bugloss {Echium v'ulgare); Dodder {Cuscuta trifolii). Mullein (V erbascum blattaria). Vervain {Verbena officinalis). Self-heal {Prunella vulgaris). Ribgrass {Plantago lanceolata). Plantain {Plantag o major). Pigweed {Amaranthus retroflexus). Fathen {Chenopodium album). Wireweed {Polygonum aviculare). Smartweed {Polygonum persicaria). Narrow-leaved dock {Rumex crispus). Sorrel {Rumex acetosella).

Home Testing.

While it is very necessary that the purity of a seed-sample under offer should be determined, it' is of equal importance that its germinationcapacity should be known. This is required not only for the purpose of estimating its true value, but also to show what quantity would be required adequately to clothe a given area, for it is . obvious that a high-germinating seed will go much further than a low-germinating one.

The necessary, conditions for the germination of almost all the commoner grass and forage-crop seeds (Poa pratensis being an exception) may, with the aid of very simple apparatus, be obtained at home. Water, air, and heat are the main requisites. Water is supplied by means of a piece of blotting-paper (or thin flannel) placed in a saucer or similar receptacle. The seeds are counted on to this material, which is thoroughly saturated every day with water. No more water should be applied than can be taken up by the blotting-paper, but it is just as necessary that the paper should not be allowed to become dry. In order to prevent too rapid evaporation of the moisture, the top of the saucer should be almost covered with a strip of glass, wood, or cardboard, a small opening being left to admit of the entrance of air. 60° to 80° Fahrenheit suffices to sprout the seed ; this is a common temperature in a warm room or a kitchen. .

The actual seed chosen for germinating should, as nearly as possible, be representative of the bulk. Thoroughly mix the entire sample, and, taking a pinch from it, indiscriminately count out exactly a hundred pure seeds. Place them on the wet . blotting-paper, partly cover, the saucer, and place it in a uniformly warm place. In counting out the seeds it is important that they should be taken just as they come, and that the common tendency to select the plumper and more promising-looking seeds should be overcome. The counting should be accurately done, so as to facilitate estimating the germination percentage at the conclusion of the test.

In seven days’ time all sprouted seeds should be counted out of the saucer, and a record kept of the number. This should be repeated at intervals of seven days until all the living seeds have sprouted. The following table shows the times in which a very good idea can be formed of the germination percentage of various seeds.

Cowgrass . . . . . . .. "'J Red clover . . . . . . .. | White clover . . . . . . .. j Alsyke . . . . - . . . . .. J* 14 days. Lucerne . . . . . . . ... Trefoil . . . . . . . . .. | • Lotus ma jor . . . . ... . . J

Lotus corniculatus . . ■ .. • . V Rye-grasses .. . . . . .. j Timothy . . ... . . .. I Mustard .. .. .. . .. <-14 days. Turnips, rape, &c. " . . .. .. | Cereals ... .. . . .. I Peas .. . . .. . . .. J Cocksfoot ■ . . .. .. .. y Fescues .. .. .. • • | Crested dogstail .. .. .. 21 to 28 days. Meadow foxtail .. .. . . .. j Fiorin .. .. • . . ' . . .. J

It is worthy of note that very slow-germinating seeds, if placed in the field, would require such a long period of favourable weather that their chances of surviving would be much reduced. ' It would probably therefore be advisable not to include in the germination-percentage any individual seeds that took longer than twenty-eight days to germinate.

At the end of the test the number of seeds recorded as having sprouted out of the 100 placed in the saucer represents the germination-percentage of the line of seed under test.

How the Department helps.

•The Biology section of the Department undertakes the . examination of 'any seed-samples that a farmer sends to the Laboratory. All such samples, and the letters about them, should be addressed to the Biologist, Department of Agriculture, Commerce, and Tourists, Customs Building, . Wellington. The accurate "analysis of the samples, and a full list of all the impurities, will be supplied, together with the germination-capacity, of the seed, i This is done free of any charge. So far as the purity is concerned, a report can be sent within a few days of the arrival of the samples ; -but the germination report cannot be forwarded until the necessary time has elapsed to complete it, which varies from a week or so in the case of certain seeds, such as many of the clovers, to several weeks in the case of certain grasses. If the farmer is in doubt about the impurities that are in the seed he has bought, or wishes to buy, he should send them to the Department, and they will be identified, and the names and qualities of the plants to which they belong will be given. . '

Points worth Consideration.

1. The loss due to weeds exceeds one million pounds sterling annually.

2. The greatest factor in the spread of weeds is the use of impure seed.

3. Always ascertain what weed-seeds are present in a sample before purchasing. 4. Reject any samples that contain an excess of weed-seeds. 5. Cheap seed is always bad, but high-priced seed is not necessarily always good. , - . 6. Never sow weed-infested seed on the score of cheapness.7. The sowing of cheap weed-infested seed is the most expensive policy that a farmer can adopt. , 8. Always ascertain the germination of grass and clover seeds before buying. 9. The weed-seed reference-card provides a ready means of identifying the more common impurities of agricultural seeds. 10. The Department of Agriculture, Commerce, and Tourists tests any seed received from farmers free of charge. Why not avail yourself of this opportunity ?