Investigations on yield in the cereals. I

Abstract

Considerations which are dealt with at length in Appendix III governed the form of the investigation upon tillering. In essence, the intention was to compare the pure lines P and A and to explore the possibilities of making accurate determinations of tillering. For reasons discussed in the Appendix, special steps were taken to secure for observation a population of plants which had had as great a uniformity of conditions as was attainable. The selection and sowing of the seed have been described in § I above. To promote further uniformity, plants of the following categories were excluded from observation: (i) all the plants of end rows; (ii) the end plants of all rows; (iii) plants which did not germinate on 26. iii. or 27. iii. (these days constituted the “modal” 2-day period of germination for the whole population); (iv) plants damaged to a noticeable degree by wire-worm or any other such agency; (v) plants whose immediate neighbour(s) in the row had died.