Water relations and plant size aspects of flowering for Agave deserti

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Bot. Gaz. (Chicago); (United States)

DOI:https://doi.org/10.1086/337630· OSTI ID:6503056

Nobel, P S

The percentage of rosettes of the monocarpic perennial Agave deserti that flowered annually in the north-western Sonoran Desert varied ca. 50-fold for the 8 yr considered. The number of days when the soil water potential in the root zone was above -0.5 MPa, enabling A. deserti to take up water, was approximately linearly related to the annual precipitation, which also varied considerably year-to-year. The percentage of flowering in a particular year could not be predicted from the number of wet days in that year, the year before, or 3 yr before (r/sup 2/ less than or equal to .10, P > .5), but there was a positive correlation between percentage of flowering and the number of wet days 2 yr previously (r/sup 2/ = .33, P = .1). Also, years with much flowering tended to alternate with those of little flowering (r/sup 2/ = .64, P = .05). Indeed, 95% of the annual variation in the percentage of the rosettes that flowered could be accounted for by the year-to-year alternations together with the number of wet days 2 yr before the flowering (P = .01). Although over 90% of the rosettes with inflorescences were large, averaging 66 leaves and inflorescences 4 m tall, flowering also occurred for a few small rosettes, averaging only nine leaves and inflorescences only 0.8 m tall. The small flowering rosettes were all attached to large flowering rosettes by rhizomes with living cortical cells, suggesting that a hormone or other chemical signal/condition could be passed to the small rosettes leading to their precocious flowering.

• Research Organization: Univ. of California, Los Angeles
• DOE Contract Number: AC03-76SF00012
• OSTI ID: 6503056
• Journal Information: Bot. Gaz. (Chicago); (United States), Journal Name: Bot. Gaz. (Chicago); (United States) Vol. 148:1; ISSN BOGAA
• Country of Publication: United States
• Language: English

Related Subjects

510100* -- Environment
Terrestrial-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ARID LANDS
BIOLOGICAL AVAILABILITY
FLOWERS
GROWTH
HYDROGEN COMPOUNDS
LEAVES
OXYGEN COMPOUNDS
PLANT GROWTH
PLANTS
SIZE
WATER