Published online by Cambridge University Press: 12 June 2017
Total nonstructural carbohydrate (hereinafter referred to as TNC) storage in roots and utilization of TNC by yellow rocket (Barbarea vulgaris R. Br.), white cockle (Lychnis alba Mill.), and hoary alyssum (Berteroa incana (L.) DC) was studied through a 1-year life cycle in plants seeded July 8, July 22, and August 5, 1966. For yellow rocket, TNC storage was most rapid during September and reached maximum levels by November 2. Younger plants stored TNC more efficiently than did older plants, but total grams of TNC per plant were greater for older plants than for younger plants. No plants bolted during the seeding year. Rapid declines in TNC of the roots began in late March, and minimum TNC levels coincided with the completion of flowering in mid-June for all plants the year after seeding. For white cockle, TNC storage was most rapid during September and early October, and reached maximum levels for all plants by November 2. There was no apparent winter injury to any of the plants. Total growth in 1967 was greatest for plants seeded July 8 and least for plants seeded August 5. Flowering began June 2 and seed were mature June 29. Adventitious buds were present on the roots of all plants on all sampling dates from September 7, 1966, through July 7, 1967. Minimum levels of TNC during spring growth were reached in mid-June. For hoary alyssum, TNC storage was most rapid during late September and October and reached maximum levels by the middle of November. TNC levels were higher in plants seeded July 22 or August 5 than in those seeded July 8. Plants seeded July 8 were flowering profusely by the middle of September, those seeded July 22 were flowering October 6, but those seeded August 5 did not flower in the seeding year. In 1967, all plants were in full bloom May 26. Minimum TNC levels were reached at full bloom and there was no accumulation of TNC as of July 7.