Effect of Size of Seed on Plant Production with Special Reference to Radish

This paper is to be regarded as a preliminary report on seed studies on the radish. Observations for a number of seasons and on a larger number of seeds should be made to settle definitely some of the phases of the subject touched on in this paper. From the data presented, however, the following conclusions seem justified: 1. The relative weights of the same sizes of seeds in different varieties differ widely, but the relative weights of the large, medium, and small seeds are approximately the same in all varieties. 2. The percentage of germination varies considerably with the large, medium, and small seeds. In some varieties the large seeds germinate best, in others the medium, and still others the small. When the average percentage of germination for the various sizes of the several varieties is computed, the difference between any of the sizes is negligible and within the limits of experimental error. 3. No definite statement can be made as to which size produces the heaviest root. In the majority of trials with the large, medium, and small seeds of the Scarlet Globe, Hailstone, and Rapid Red varieties the medium seeds gave the best results; with the Crimson Giant forcing variety the small seeds always produced the heaviest roots; and in the one trial of the Scarlet Button variety the large seeds produced the heaviest roots. When taken as a whole and averaged, the medium seeds produce the heaviest roots. 4. With reference to the percentage of salable roots, the medium seeds in every variety, except the Crimson Giant forcing, produce the highest percentage of salable roots. 5. The question as to why in one variety the small seeds should give the largest roots, and other varieties the large, and in still others the medium remains unanswered. Theories might be formuated, but the first requisite should be additional dependable data. 6. Apparently there is a definite correlation between the weight of the plants and the weight of the roots. 7. From the data herein recorded it seems established that the results obtained with one variety are not necessarily comparable with another variety, as stated by Galloway (7) and Cummings (3).