Physiological and Environmental Factors Affecting Shoot Tissue Boron Concentration of Pansy (Viola x wittrockiana), Petunia (Petunia x hybrida), and Gerbera (Gerbera jamesonii) Plugs.

["Hoaglands";Hydroponics;Nutrient deficiency

Krug, Brian Alan ; Dr. Paul V. Nelson, Committee Member,Dr. Randy Wells, Committee Member,Dr. Brian E. Whipker, Committee Chair,Dr. John D. Williamson, Committee Member,Krug, Brian Alan ; Dr. Paul V. Nelson ; Committee Member ; Dr. Randy Wells ; Committee Member ; Dr. Brian E. Whipker ; Committee Chair ; Dr. John D. Williamson ; Committee Member

University:North Carolina State University

关键词: ["Hoaglands";    Hydroponics;    Nutrient deficiency;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/5326/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

The overall objectives of these studies were to characterize and determine the causes of abnormal growth observed in pansy (Viola x wittrockiana), petunia (Petunia x hybrida), and gerbera (Gerbera jamesonii) plug production.Observed symptoms included distorted, curled and thickened leaves, abortion of apical meristems and proliferation of lateral shoots.Symptoms have been attributed to a calcium (Ca) or boron (B) deficiency.Calcium and B deficiencies were induced; plants deficient in Ca became discolored and eventually necrotic, while symptoms on plants deficient in B were similar to those observed in plug production.It is improbable that insufficient B is the cause of B deficiency; growers use complete liquid fertilizer at every irrigation.High substrate pH causes B in the substrate to be unavailable to the plant.When germination substrate was incorporated with four increasing rates of dolomitic limestone, substrate pH increased and the shoot tissue concentration of B decreased.Plants take up B passively through the transpiration stream; therefore B uptake is linked to the rate of transpiration.Plants were exposed to 3 degrees of drought stress either by drying the substrate or the use of polyethylene glycol.Shoot concentrations of B were not effected by either drought stress treatment.Abscisic acid was applied as a foliar spray or substrate drench, each at 2 different concentrations, to decrease transpiration.Abscisic acid resulted in a decrease of both transpiration and shoot B concentration.High relative humidity (RH ) can also decrease plant transpiration; plug production requires elevated levels of RH to ensure germination and to maintain hydration of young seedlings.Plants were grown in ambient or high RH; plants grown in high RH had lower shoot tissue concentrations of B.To attempt to counteract the effect of high RH, air flow was increased on a constant basis.Providing constant airflow did not increase transpiration or shoot tissue concentration of B.