The possibilities of mechanical mixture or accidental substi tution of one variety for another during handling, cleaning and storage of seed must be most carefully guarded against. The similarity in appearance of many kinds of seed would, with careless handling, lead to hopeless confusion and to the probability of heavy claims for damages from the purchaser who planted mixed seed. Various methods are therefore employed with the object of checking the identification of the bulks of stored seed. In addition to a careful and rapid double check system of keeping stock most of the large seed merchants maintain trial grounds in which a small quantity of every lot of seed handled is grown. In this way they are in a position to satisfy themselves as to the genuineness of the varieties and the general quality of the seed supplied by their growers. In these trial grounds too, the old varieties are constantly under test and new varieties are the object of close observation in order to determine their merits. Finally, it is necessary, by a laboratory test, to ascertain the vitality and analytical purity of the seed. Many seed merchants maintain their own laboratories and employ expert analysts for this pur pose, others make use of the facilities offered by the State seed testing stations. The facts established by these tests enable the purchaser to gauge with some degree of accuracy the quality of the seed he is buying. The percentage of purity will show him what proportion of the bulk is the seed he requires and how much other seed, weed seed and foreign matter is present. The percent age of germination, ascertained as it is by a test carried out under the most favourable conditions in the laboratory, does not neces sarily show the number of plants that will be obtained from the seed when it is planted in the field or garden, but it does give a fair indication of the vitality of the seed and is absolutely reliable when comparing the quality of various lots of seed. Other facts
which can be elicited as a result of a laboratory inspection include the freedom or otherwise of the seed from seed borne diseases, insect and fungus attacks and, with certain definite limitations, proofs as to accuracy of variety and country of origin.
A transaction in seeds is not completed with the sale of the seed. The seller cannot assume responsibility for the methods adopted by his farmer or gardener customers, nor for the weather and soil conditions; nevertheless a satisfied customer is not secured until the harvest is reaped. Therefore it is one of the duties of the retailer to educate his customer to purchase the kind of seed which will bring the most satisfactory results.
It is not even sufficient for the seedsman to sell seeds of good appearance and with a high percentage of germination, freedom from weeds and so on ; knowledge as to the adaptability of par ticular stocks and strains is advancing rapidly, and it is the busi ness of the seedsman to supply his customers with those stocks or strains which are best adapted to the soil and climate in which they are to be grown.
See also SEED TESTING. (H. CH.)