PRACTICAL ADVICE ON SEED-TESTING The quality of agricultural seeds, especially of forage crops, has been given much more attention in Europe than in America. European countries have seed control in various forms, with over one hundred seed-control stations, some of them with an international reputation. We have developed a system by means of which commercial fertilizers are sold under guaranteed analyses, and a large part of the work of some of our state agricultural experiment stations is given to making these chemical analyses ; but comparatively little atten tion has been given to the quality of seeds. No seeds sold in this country are guaranteed as to purity and germination, and but few experiment stations have facilities for seed - testing. The United States Department of Agriculture and some of the agricultural experiment stations, however, have done much to show the importance of good seeds. Publications have been issued calling atten tion to the quality of various kinds of seeds on the market, and samples have been tested for the infor mation of the senders.
Large quantities of low-grade screenings, espe cially of clover and alfalfa, are imported annually to be mixed with better seeds and sold as medium and low grades. Besides dirt and dead seed, these screenings contain large quantities of weed seeds.
Beal has shown (Bot. Gaz., August, 1905, "The Vitality of Seeds") that the seeds of many com mon weeds grow after having been buried in the ground for twenty-five years. Among these are pigweed, black mustard, shepherd's purse, pepper grass, evening primrose, smart weed, purslane, curled dock, pigeon grass, chickweed and mayweed. The purchaser of low - grade seed is fouling his land with weeds which may appear for years afterward, whenever the conditions are right for their germination. Farmers make the mistake of thinking that there is not so much difference in quality as in price, while as a matter of fact the good seed in the low grades costs often many times as much per pound as the good seed in the best grades.
Testing for purity.
Everyone buying seeds should have some kind of a lens with which to examine them. The form shown in Fig. 209, costing twenty-five to fifty cents, is satisfactory. By spreading grass or clover seed thinly on a sheet of white paper and looking at it carefully with a lens, it is easy to detect the presence of any considerable amount of weed seeds or chaff. The seeds used as adulterants are much more difficult to distinguish, and in all cases of sus pected adulteration samples of the seed should be sent for examination to the state agricultural ex periment station or to the Seed Laboratory of the United States Department of Agriculture. All seed
should be practically free from weed seeds and chaff, and contain no adulterants. Clover and alfalfa should be bright and contain no brown seeds or dodder seed.
Testing for germination.
All the quick-germinating seeds, such as cloy?", timothy and grain, can be easily tested for ger mination by any one with the simple tester shown in Fig. 210. Mix the seed thor oughly and count out 100 or 200 seeds just as they come, mak ing no selection ex cept to discard any weed seeds. Put them between a fold of canton flannel or some similar cloth that has been washed in boiling water, tak ing care not to let the seeds touch one another. Lay the cloth on a plate, moisten it well but do not saturate it, cover with another plate and keep at a temperature of about 70° F. Every day count and take out the sprouted seeds. In four to ten days all of the good seeds will have sprouted, and the percentage of seed that will grow is known.
Some of the grass seeds are more difficult to test, requiring more exact conditions and an alter nating temperature. In all cases where seeds do not germinate well in the simple tester shown, it is best to send them away to be tested before dis carding them.
Adulteration.
Several of our most important forage crop seeds are frequently adulterated with seeds costing one third to one-half the price of those with which they are mixed. Red clover, alfalfa, Kentucky blue grass and orchard-grass seed are the principal ones The seed of yellow trefoil is imported in large quantities from Germany to be used as an adulterant of red clover and alfalfa. It is a low growing, leguminous plant not cultivated in the United States and of no value where red clover or alfalfa will grow. Bur-clover seed, which is combed out of South American wool, is also imported from Germany and mixed with alfalfa seed. English and Italian rye-grass and meadow fescue seed are frequently mixed with orchard-grass seed in vary ing proportions. Canada blue-grass seed, although used to some extent in this country, is imported in large quantities from Canada, to be mixed with, or sold as Kentucky blue-grass seed. All of these seeds used as adulterants resemble so closely the seeds with which they are mixed that they are difficult to distinguish. In the following discussion, enlarged pictures are given of the true seed, in order that the examiner may distinguish adulter ants. The sedges frequently occur with grasses but are not used as adulterants. Some of the seeds or fruits are shown in Fig. 211.
Farm seeds and adulterants.