Articles
CHANGES IN ROOT SURFACE AREA, NUTRIENT ABSORPTION ACTIVITY, AND ROOT CARBOHYDRATE CONCENTRATION DURING CROP CYCLES OF ROSA HYBRIDA ‘KARDINAL’ PLANTS GROWN IN SOLUTION CULTURE
Article number
766_7
Pages
73 – 80
Language
English
Abstract
Cut flower rose production is often managed to produce a flush of harvestable flowers in time for particular holiday.
Such crops go through cycles of vegetative and reproductive growth.
Cyclical patterns of nutrient absorption are generally shifted in time with a decline in uptake rates as new flower shoots appear and increasing rates of uptake as shoots reach harvestable maturity.
The objective of this experiment was to determine how root surface area (RSA), N, P, K absorption activity (uptake per unit root area), and root total nonstructural carbohydrate (TNC) concentration varies over such crop cycles under conditions of high or low light.
A sequential harvest experiment was conducted using one-year old Rosa hybrida ‘Kardinal’ plants on ‘Natal Briar’ rootstock in solution culture.
Plant RSA did not change significantly during the high light crop cycle and averaged 14400 cm2 plant-1. Under low light, RSA declined following a previous harvest until day 15/20, followed by an increase until shoot maturity.
N absorption activity declined from 8.6 ρmol cm-2 s-1 just prior to cycle initiation (day 0) to 3.1 ρmol cm-2 s 1 at day 15. Absorption rates steadily increased as flower shoots reached maturity to 8.2 ρmol cm-2 s-1 at day 30. K and P followed similar patterns of absorption.
Root TNC concentration did not change during the high light cycle.
Under low light, root TNC concentration dropped by half (from 40 to 18 mg g-1 during days 0 to 5) then remained relatively stable until the last five days of the crop cycle when the concentration increased to 36 mg g-1. Overall, variation in N, P, K absorption was primarily dependent on changes in physiological root activity rather than changes in RSA.
Such crops go through cycles of vegetative and reproductive growth.
Cyclical patterns of nutrient absorption are generally shifted in time with a decline in uptake rates as new flower shoots appear and increasing rates of uptake as shoots reach harvestable maturity.
The objective of this experiment was to determine how root surface area (RSA), N, P, K absorption activity (uptake per unit root area), and root total nonstructural carbohydrate (TNC) concentration varies over such crop cycles under conditions of high or low light.
A sequential harvest experiment was conducted using one-year old Rosa hybrida ‘Kardinal’ plants on ‘Natal Briar’ rootstock in solution culture.
Plant RSA did not change significantly during the high light crop cycle and averaged 14400 cm2 plant-1. Under low light, RSA declined following a previous harvest until day 15/20, followed by an increase until shoot maturity.
N absorption activity declined from 8.6 ρmol cm-2 s-1 just prior to cycle initiation (day 0) to 3.1 ρmol cm-2 s 1 at day 15. Absorption rates steadily increased as flower shoots reached maturity to 8.2 ρmol cm-2 s-1 at day 30. K and P followed similar patterns of absorption.
Root TNC concentration did not change during the high light cycle.
Under low light, root TNC concentration dropped by half (from 40 to 18 mg g-1 during days 0 to 5) then remained relatively stable until the last five days of the crop cycle when the concentration increased to 36 mg g-1. Overall, variation in N, P, K absorption was primarily dependent on changes in physiological root activity rather than changes in RSA.
Publication
Authors
N.S. Mattson, J.H. Lieth, Gyeong-Lee Choi, Wan-Soon Kim
Keywords
roses, cut flowers, root growth, root physiological activity, carbohydrates
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