Nature and Rate of Development of Root System of Convolvulus arvensis

Abstract

A study of field-grown plants from seed without competition in a typical upland soil in eastern Kansas. Periodic excavations during 120 weeks after seedling emergence disclosed that the root system consisted of the original tap root (primary vertical root) and one to many permanent lateral roots (1st order) which eventually grew downward to become secondary vertical roots. Unless injury or too severe competition prevented, many additional permanent lateral and secondary vertical roots of the 2d and higher orders arose. These accounted for the horizontal spread of the plant which was as much as 10 ft. in the 1st growing season and 17 ft. by the middle of the 3d growing season. At that time there were many vertical roots 14-16 ft. deep and one 23 ft. deep. The shoot development of old plants was wholly from root-borne buds. These were most numerous at the bend separating the lateral root of any order from its yertical phase.