Search Results

You are looking at 11 - 20 of 81 items for :

  • "dilution effect" x
Clear All

Diploid (2x) and autotetraploid (4x) Citrus L. rootstock cultivars were grown at elevated CO2 to obtain insights into limitations on growth and net gas exchange that have been associated with tetraploidy. Well-nourished 2x and 4x seedlings of `Volkamer' lemon (Volk, C. volkameriana Ten & Pasq.), `Troyer' citrange [Troy, C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.] and `Cleopatra' mandarin (Cleo, C. reticulata Blanco.), were grown in greenhouses at either ambient or twice ambient CO2 for 4 months. Plant growth, water relations, mineral nutrition, and net gas exchange characteristics of leaves were measured. Most 4x plants were smaller and had lower rates of whole plant transpiration but shorter fibrous roots than 2x plants. Fibrous roots of 4x were thicker than 2x roots as indicated by a lower specific root length (SRL) in 4x than in 2x roots. Root hydraulic conductivity was correlated to total plant growth but there were no effects of CO2 or ploidy on root conductivity. Tetraploid leaves had lower N concentrations than 2x leaves when expressed on a dry weight basis but these differences disappeared when N concentration was expressed on an leaf area basis because 4x leaves had more leaf dry weight per area (LDW/a) than 2x leaves. Plant growth was greater and SRL was lower at elevated CO2 than at ambient CO2. LDW concentrations of N, P, and K were lower at elevated CO2 than at ambient apparently due to a growth dilution effect. LDW/a, net CO2 assimilation (ACO2), and leaf water use efficiency were greater at elevated CO2 than at ambient. Overall, there was no effect of ploidy on ACO2 but 4x Volk and Troy had lower rates of ACO2 than their 2x at elevated CO2. Net gas exchange of tetraploid leaves was less responsive to elevated CO2 than 2x leaves. The low SRL of tetraploids was correlated with low whole plant transpiration rates and low leaf area-based N concentrations, which may be operative in determining the growth characteristics associated with tetraploidy.

Free access

hypothesized that increasing yields has resulted in decreased concentrations of mineral elements in produce because of a “dilution effect” caused by plant growth rates exceeding the ability of plants to acquire these elements ( Jarrell and Beverly, 1981 ) that

Free access

, which resulted in the highest quality scores, had some of the lowest foliar K concentrations. This was likely due to a dilution effect. On the other hand, treatments 20 and 25, which had statistically equivalent quality scores to treatment 22, had some

Free access

have a dilution effect on THC, THCA, and CBGA. Although the dilution effect was apparent with increasing fertilizer rate, it did not have a substantial impact on the total per-plant yield of most cannabinoids. This was evidenced by a lack of correlation

Free access

be further attributed to a dilution effect because Ca 2+ uptake lags behind the rapid increase in fruit mass ( Saure, 2005 ). Similarly, a transient decrease in fruit [Ca 2+ ] during the rapid cell expansion phase has been noted in tomato, where [Ca

Open Access

are believed to accentuate K deficiencies in palms, presumably because of a dilution effect ( Broschat, 2005a ). On highly leached, low cation exchange capacity (CEC) sandy soils, such as those commonly found within the Atlantic coastal plain of the

Full access

similar results at the 10-true-leaf stage (49 DAT) compared with the six-true-leaf stage (35 DAT), suggested that this response could be attributable in part to a “dilution effect” or use of the fatty acids synthesized to repair cell damage as a result of

Free access

cultivar differences in root GSL concentrations could have been the result of a dilution effect, because JR roots have lower GSL concentrations than SQ roots but larger root yields than SQ. We attempted to compensate for dilution effects by using roots of

Free access
Author:

absence of Zn can lead to Zn deficiency through a dilution effect brought about by an increase in growth resulting from the N application ( Loneragan and Webb, 1993 ). Although acidifying N fertilizers such as AS can lead to an increase in the availability

Open Access

late stage is related to the nutrient dilution effect as the plant allocates a higher amount of assimilates to the heart growth than those partitioned to the rosette formation. The dilution effect could also in part explain the consistently lower N

Free access