Miscellaneous. 



358 



[April 1908. 



placed under field conditions. Let us 

 now consider in some detail the pro- 

 cedure followed in ascertaining the 

 germinating power of seed :— 



1. Germinating Bed.— Excepting in 

 the case of some of the larger seeds, they 

 are placed, without previous soaking, 

 directly in the seed-bed, without being 

 in contact with one another. The seed- 

 bed varies. In some cases strong folded 

 blotting paper is used, in others porous 

 clay dishes of varying thickness, in 

 others sand, and in yet others (especially 

 cereals) ordinary soil in flower-pots or 

 saucers in a greenhouse. I shall not stop 

 to mention the practical details to be 

 observed in keeping these media pure. 

 In this Station the same seed is tested 

 in two or more of these media and the 

 average result taken, this being further 

 checked by the simultaneous germin- 

 ation of a " control " seed of known 

 germinating power. I have found this 

 additional precaution very useful in 

 cases of dispute between buyer and 

 seller, and recommend it for general 

 adoption. 



2. Temperature. — Whatever the na- 

 ture of the bed may be, it is essential 

 that its temperature should be under 

 control and should remain constant. In 

 most cases the temperature recom- 

 mended is 20° C. Here our results have 

 been more satisfactory when the thermo- 

 meter of the incubator was 24° C. 

 Certain seeds (Poa, Dactylis, Beta, etc.) 

 are found to germinate better if they are 

 also exposed each day to a temperature 

 of 30' C. for six hours, in imitation of 

 the diurnal rise of temperature in nature. 



(3) Moisttire and Seed-bed. — The pro 

 cess of dehydration through which a 

 seed passes in ripening has its counter- 

 part when germination is taking place. 

 A dry seed will not germinate, no matter 

 how favourable the other conditions 

 may be. If, on the other hand, a seed is 

 left water-logged it will not germinate, 

 but in a few days die and rot away. 

 The seed-beds used in testing are of a 

 porous nature, in contact by partial 

 immersion or otherwise with fresh water, 

 so that the necessary moisture reaches 

 the seed, generally by capillarity. For 

 most seeds the amount of moisture so 

 obtained is sufficient. This holds true 

 for the seed-bed, whether of porous clay, 

 sand, asbestos, or blotting-paper and 

 for most seeds. 



(1) Air. — Fresh air is usually provided 

 for in the incubators by ventilators, 

 Seeds are particularly sensitive to inju- 

 rious chemical substances, whether in the 

 seed-bed or in the gas often used in 

 heating the incubator. 



(5) Light.— Most seeds seem indifferent 

 to sunlight, i.e., the seeds germinate 

 equally well in darkness or light. It is 

 a popular saying that a seed in nature 

 germinates best when covered by a 

 layer of soil equal in depth to the dia- 

 meter of the seed. Exposure to direct 

 sunlight brings with it difficulties in 

 regulating the temperature of the incu- 

 bator. In a few cases, e.g., the Poas- 

 exposure to light has been shown to be 

 distinctly beneficial, expediting the 

 germination of the seed by one to three 

 or four days, or increasing its percentage 

 of germination. 



Where the seed is of good average 

 quality, i.e., such as a seedsman should 

 s^ll and a farmer sow — the foregoing 

 conditions can be kept so generally con- 

 stant that the test will be quite reliable, 

 and may be safely taken as an indication 

 for sowing purposes of the quality of the 

 seed. 



Objections raised against Seed- 

 Testing. 



(») Unreliability. — Occasionally object- 

 ors to seed- testing quote cases : — 



(1) In which several Stations have 

 given widely different reports on the 

 same seed. 



(2) In which the same seed tested by 

 the same person under different methods 

 has given different results. 



The particulars as to the quality of 

 the seed, the number of seeds tested, 

 the use or not of a " control " seed, the 

 temperature of the incubator, the 

 degree of familiarity with the incubator, 

 and the experience of the tester are 

 all omitted. 



The difficulty with the Poas is the usual 

 case quoted. They are delicate seeds, 

 but not beyond reliable testing, and, 

 further, they form an infinitesimal part 

 of the seed trade. A few years ago an 

 Irish landowner sent independently to 

 a seed firm, strongly opposed to seed- 

 testing and to me, samples of " tussock " 

 grass seed. The fact that the firm 

 identified this seed of a valuable fod- 

 der grass Poa flabeltata, or Dactylis 

 coespitosa, as a worthless grass. Aria 

 coespitosa, cannot be quoted as proof 

 of their general unreliability as seeds- 

 men. The Committee was further told 

 that only skilled hands could prepare 

 a uniform mixture of seeds of grasses 

 and clovers. The mixture made in the 

 seed warehouse rearranges itself in the 

 journey to the farm, and needs remixing 

 before being sown. The purchase of 

 mixtures is being, for obvious reasons, 

 more and more discouraged by the 

 farmers' advisers. 



