Treatment of Seed

Timaru Herald, Volume CXXXVII, Issue 19632, 28 October 1933, Page 15

Treatment of Seed

The Russians, in expanding their production under the Fve Year Plan, have met with numerous obstacles, not the least of which has been a rigorous climate with a short growing season. Winter snows preclude autumn sowing of wheat, while spring wheats are damaged by high summer temperatures just at the time they are coming into ear. For these conditions the chief requirement in a spring wheat is early ripening; a variety may be superior in all other respects and yet may suffer damage owing to its lateness. The problem then, has been how to shorten the period of time necessary for a plant sown under ordinary field conditions to reach the fruiting stage. This has been done most successfully by the pre-treatment of the seed, or vernalisation, as It Is termed. The Russians have introduced a new and revolutionary concept in respect to plant growth. They make a distinction between the phenomenon they refer to as growth—increase in weight and size of the plant—and the phenomenon they refer to as development, by tfhich they understand the transition of the plant to successive stages, in other words, a qualitative change in the nature of the plant. They claim that these two processes are separate and distinct, "that the transition to the reproductive stage is not only independent of the size and age of the plant, but is not correlated in time with growth.” Further, they claim that the process of preparation of a plant toward reproduction may occur in the embryo and may be separated in time from the growth of the plant. Phenomenon of Growth. We have, in the past, tacitly accepted that continued growth of a plant would eventually lead to blossoming and fruiting; in other words, that growth and development toward reproduction were inseparable phases of the phenomenon of growth. Russian workers claim that “the set of external conditions required by a plant for the completion of the stages of development, and that required for growth, frequently do not coincide, not only in the sense of the factors, but also in the sense of the factors themselves. A plant may grow for an indefinite period, increasing in weight and size, under the influnece of appropriate conditions and yet not progress toward the next stage in development. Millet and maize, when grown under constant illumination, do not pass into the flowering stage because of the absence of darkness, whereas their growth may continue without interruption.” The fact that the process of preparation of a plant toward reproduction may occur in the embryo and may be separted in time from the growth of the plant, makes possible the practical application of the method of vernalisation, wheih consists of allowing the influence of the factors, which make possible the occurrence in the seed material of the processes which lead to the reproduction stages.

Method for Wheat. The method employed for treating wheat is as follows:—The grain is moistened with one-third its weight of water and spread out in layers 9in to lOin. deep on a floor at a temperature of 55-60 degrees Fharenheit. As soon as any shoots are observed to have pierced the grains, vernalisation should be begun. The treatment consists in holding the germinating grain at a temperature of 38 degrees Fharenheit for 12 to 15 days, the grain being well stirred each day to prevent mould growth and to secure an even temperature. Crops grown from vernalised feed have matured 20 to 26 days eartler than crops sown at the same time with untreated seed.

NEW RUSSIAN PLAN EXPLAINED

Maize, millet, Sudan grass and sorghum differ from wheat in requiring a combination of high temperature and short daily periods of illumination for reproduction. They require light for the processes of growth, and darkness for reproduction. Emphasis has been laid on the fact that these influences are exerted by light and darkness themselves, and not necessarily by an alternation of the two. Darkness and Reproduction. After the application of all the requisite darkness in one dose to the seed, the resulting plants require no

further period of darkness to enable them to pass through the reproductive phases. The method consists in germinating the seed, as in the case of wheat. The seeds'should then be kept in darkness at a temperature of 77 to 86 degrees Fharenheit for a period varying from five to 15 days, according to the type of seed being treated. The method, as applied to potatoes, consists in the application of continuous illumination in a green house at

a temperature of 60 to 76 degrees Fharenheit far 20 to 30 days before planting. The potatoes should be treated on a wire or string and uniformly illuminated by sunlight during the day and strong electric light by night. The practical application of such methods in New Zealand, if successful, may find scope in the growing of early vegetables for market under field conditions. Their chief Interest, however, lies not only in their immediate practical development, but also in the new outlook they provide on the phenomenon of growth and development, to which great Interest is given by the new Spangenberg process now undergoing trial at Reading, in England.