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|Title:||A Study of Pothos (Epipremnum Aureum) Water Requirements|
|Author(s):||Sawwan, Jamal Suleiman|
|Department / Program:||Horticulture|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Biology, Plant Physiology|
|Abstract:||Pothos (Epipremnum aureum) is a very important and attractive ornamental, well-suited for interior environments; however, little is known about its water requirement. The main object of this research was to determine the water requirement of Pothos.
This research was divided into two main categories, experiments dealing with characterization of Pothos water status (including what, when, and where to measure) and characterization of the effects of water deficit on Pothos growth functions and yield. The intent of these experiments was to provide information about the critical stress limits where water stress significantly affects or completely stops these functions.
Of the three methods of characterizing plant water status tested, gravimetric relative water content, pressure chamber water potential, and steady state porometer stomatal opening, the pressure chamber measurement seemed the most suitable. Although convenient to make, porometer measurements proved inconsistent. Relative water content measurements were consistent, but not practical (tedious and slow).
Sampling location had a significant effect on water status measurements. Differences were observed in leaves of different ages, especially as water deficit became more severe. Older leaves were observed to have generally lower water potentials than younger ones. Sampling time also proved significant; the most consistent measurements were obtained at predawn (most stable water status period in the diurnal cycle).
Pothos plants deprived of water to induce progressively increasing water stress were monitored for water status and primary yield factors including leaf growth (expansion and net photosynthesis) and retention (survival). Water deficit had a very significant effect on leaf expansion growth. Leaf expansion decreased with increasing water deficit and stopped altogether at relatively high water potentials of about $-0.23$ MPa.
Decreases in net photosynthesis and respiration rates also paralleled the onset and development of water deficit. Net photosynthesis decreased proportional to leaf water potential and ceased altogether at water potentials of about $-0.8$ to $-0.9$ MPa. Although respiration decreased to a very low level, it did not stop on leaves surviving the water deprivation.
Pothos was observed to survive a long period of water deprivation; but, the quality (its appearance) of the survival was questionable. For Pothos the concept of critical stress limits seems quite nebulous.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987.
|Date Available in IDEALS:||2014-12-16|