scholarly journals Subirrigation Effects on Larch Seedling Growth, Root Morphology, and Media Chemistry

Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Fangfang Wan ◽  
Amy L. Ross-Davis ◽  
Wenhui Shi ◽  
Christopher Weston ◽  
Xiehai Song ◽  
...  

Subirrigation (SI), where water is provided to container seedlings from below and rises through the growing media via capillary action, is regarded as an environmentally-responsible method of delivering water and fertilizer to nursery-grown plants, resulting in more uniform crops and improved production efficiency. While a concern around adopting this method is that a potential higher salt concentration in the upper layers of growing media under SI may inhibit root growth and result in decreased plant quality, few studies have focused on how root morphology is altered by SI. Therefore, a balanced two-factor factorial design with three rates of fertilization (50, 100, and 150 mg N seedling−1) and two irrigation methods (SI or overhead irrigation (OI)) was used to examine the growth response of Prince Rupprecht’s larch (Larix principis-rupprechtii Mayr) seedlings for one nursery season. Associated changes between rhizosphere electrical conductivity (EC) and root morphology of different root size classes were analyzed. Results show that (1) height, root-collar diameter, and root volume were similar between seedlings grown under SI and OI. However, (2) compared to seedlings receiving OI, SI-seedlings had less root mass, length, and surface area but greater average root diameter (ARD). (3) Morphological differences were evident primarily in root diameter size classes I–III (D ≤ 1.0 mm). (4) Fertilizer rate influenced root length and surface area up to 130 days after sowing but affected ARD throughout the growing season such that seedlings treated with 50 mg N had smaller ARD than seedlings treated with 100 mg N. (5) As the growing season progressed, SI-media had significantly higher EC compared to OI-media and EC increased with increasing fertilizer rate under SI but not under OI. These results indicate that SI can produce larch seedlings of similar height and root collar diameter (RCD) compared to OI, but root systems are smaller overall with fewer small-diameter roots, which may be related to high EC levels in SI-media, which is exacerbated by the use of high rates of fertilizer. Therefore, the EC in the media should be monitored and adjusted by reducing fertilizer rates under SI.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wahidullah Rahmani ◽  
Mohd Nazre Salleh ◽  
Mohd Zaki Hamzah ◽  
Aminu Abdu ◽  
Mohamad Fakhri Ishak ◽  
...  

Tropical Montane Cloud Forest (TMCF) is among the most vulnerable habitats to fragmentation, deforestation, and global climate change. A successful restoration program requires a comprehensive understanding of variables influencing seedling efficiency. This study was conducted on Sg. Terla Forest Reserve Cameron Highlands, Pahang, Malaysia. In this study, we used a randomized complete block design (RCBD) and measured the Magnolia champaca height, root collar diameter, diameter at breast height, plant survival, root diameter, main root length, lateral root length, root coiling, root direction, and chlorophyll content. The soil samples were taken to study the effect of different mulching materials on soil characteristics. We also measured soil compaction, soil texture, soil colour, soil moisture content, soil organic carbon, total nitrogen, total sulphur, available phosphorus, and exchanged potassium. This study indicates that mulching had no significant effect on plant height, diameter breast height, root collar diameter, and chlorophyll content between treatments. Although mulching had a significant effect on root diameter, main root length, and root distributions among treatments while for lateral root length and root:shoot ratio did not show a significant effect among treatments. However, oil palm mulching treatment had a greater effect on plant height, root collar diameter, and diameter at breast height growth, among treatments. Mulching significantly affected soil pH, soil moisture content, total sulphur, and potassium exchange. In contrast, mulching did not significantly affect soil organic carbon, total soil nitrogen, and soil available phosphorus between treatments.


1991 ◽  
Vol 21 (2) ◽  
pp. 175-185 ◽  
Author(s):  
S. C. Grossnickle ◽  
J. T. Arnott ◽  
J. E. Major

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings from four dormancy induction treatments (DIT) (i.e., long-day dry, long-day wet, short-day dry, short-day wet) were planted on a coastal reforestation site in British Columbia and monitored for physiological response and morphological development over the first growing season. Seedlings in all DIT showed a similar net photosynthetic, needle conductance, and shoot water potential response to seasonal low temperature, non droughty, and late summer drought conditions. Pressure–volume analysis at the beginning of the growing season (late February) showed short-day wet seedlings to have lower saturated and turgor loss point osmotic potentials than other DIT, while at the end of the growing season (October) there was no osmotic potential difference between DIT. At the end of the growing season, short-day wet seedlings had a much lower maximum modulus of elasticity than other DIT, indicating their shoots were still elongating. Morphological assessment 1 month after field planting showed short-day DIT seedlings had less needle damage and greater root development in response to continuous low temperature exposure. Four months after planting, long-day wet seedlings had the greatest shoot (i.e., height, root collar diameter) and root development in response to mild temperatures and high soil moisture conditions. Eight months after planting, survival was between 95 and 97% for all DIT. Long-day DIT seedlings had the greatest height and all DIT had similar root collar diameter and root development. Short-day DIT seedlings had the best shoot/soil roots ratio. Short-day wet seedlings had the least number of stem units per centimetre of new shoot development throughout the growing season. Results are discussed in reference to stock quality assessment presented in the first paper of this series.


2017 ◽  
Vol 59 (4) ◽  
pp. 281-286
Author(s):  
Maria Hauke-Kowalska ◽  
Winicjusz Kasprzyk

AbstractPruning is one of the important cultural treatments that have potential to influence hardwood seedling morphology. The aim of the study was to compare the growth of pedunculate oak seedlings, performed pruning roots, in the second growing season, fertilised full and reduced dose of nitrogen.A total of 24 experimental plots, each with an the area of 0.04 ha, were designated. The roots pruning were made at the end of February 2014 using root pruning machine EGEDAL. The fertilisation, for all seedlings, was performed using ammonium nitrate in an amount of 25 kg ha−1of nitrogen. The second fertilisation was performed only for variants 2 and 4. For these variants, urea was used in an amount of 25 kg ha−1. At the end of the growing season, the root collar diameter and the height of seedlings were measured.A dose of nitrogen affects the height of pruned seedlings. The effect of the full dose of nitrogen on the height of the pruned seedlings was a statistically significant (p≤ 0.05). There was no statistical difference in the height of the seedlings without pruning, fertilised with different dose of nitrogen.Analysis of root collar diameter showed the significant differences between the variants. The Tukey test, at the significance level ofp≤ 0.05, showed a significant impact on the root collar diameter of pruned seedlings but no proven effect of nitrogen fertilisation. To conclude, we found that it is reasonable to reduce the doses of nitrogen fertilisation to half of recommended amount (25 kg ha−1) if the root system is not pruned during the second growth year. Seedlings that has received pruning should be fertilised using the recommended doses of nitrogen.


1988 ◽  
Vol 5 (4) ◽  
pp. 245-247
Author(s):  
Lisa J. Buse ◽  
Robert J. Day

Abstract The principal objective of this research was to evaluate the effect of root pruning followed by wrenching on the morphological quality of 2 + 2 white spruce transplant stock during the final year on the nursery. In 1984, white spruce transplants were root pruned: (1) before shoot elongation; (2) during elongation; and (3) after elongation, followed by root wrenching at 28-day intervals until September (4, 3, and 2 times, respectively). In 1985, similar stock was root pruned before shoot elongation and (1) root wrenched at 21-day intervals (4 times), and (2) root wrenched periodically (twice). In both years, height and root collar diameter growth were monitored throughout the season. In the fall, morphological quality was assessed and bud samples were collected to determine the effects of root conditioning on primordia development. Root conditioning modified the morphology of stock in both years by reducing height and root collar diameter and inducing the development of a compact fibrous root system. Early season root pruning followed by wrenching at regular intervals throughout the growing season had the most effect on shoot and root morphology. Differences in results between years were attributed to environment. North. J. Appl. For. 5:245-247, December 1988.


HortScience ◽  
2006 ◽  
Vol 41 (6) ◽  
pp. 1416-1420 ◽  
Author(s):  
Joanne E. MacDonald ◽  
John N. Owens

The effects of different dormancy-induction regimes on first-year containerized coastal Douglas fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii] seedling morphology and physiology in the nursery, as well as seedling survival and performance after one growing season in a common garden, were investigated. In early July, three dormancy-induction regimes were applied: moderate moisture stress (MS), short day (SD), and short day with moderate moisture stress (SD+MS). In early October, seedling height, root collar diameter, and shoot dry weight were unaffected by regime, but root dry weight was reduced in seedlings from the MS and SD+MS regimes compared with the SD regime. At this time, morphogenesis was completed in all terminal buds of seedlings from both SD regimes, whereas it continued in all terminal buds of seedlings from the MS regime. Furthermore, 25% to 88% of terminal buds from the SD regimes were endodormant, but none from the MS regime were endodormant. In March, budbreak occurred at the same time in seedlings from the two SD regimes and was earlier than in seedlings from the MS regime; root growth capacity was unaffected by regime. After one growing season, there were no regime differences in seedling survival, root collar diameter, shoot dry weight, root dry weight, length of the current-year leader, or number of needles on the leader.


2007 ◽  
Vol 64 (1) ◽  
pp. 23-29
Author(s):  
José Geraldo de Araújo Carneiro ◽  
Deborah Guerra Barroso ◽  
Luis Maurício da Silva Soares

Seedlings compete for nutrients, water and light. The available area for each seedling affects their behavior related to requirements for these resources. This experiment evaluated the influence of five plant densities on the growth of bare root Pinus taeda, L. seedlings in a nursery after outplanting. The analyzed characteristics were: height (H), root collar diameter (D), H/D ratio, and dry matter weight. Higher densities stimulated H growth and the lowest densities increased D average and dry matter weight and lowered the H/D ratio. Seedlings were distributed by H, D and H/D classes. Higher densities had a larger number of seedlings in larger H classes. Larger numbers of seedlings with larger D and lower H/D ratios were found in lower densities. Ten months after outplanting the seedlings grown in lower densities had higher survival percentages and growth. Some saplings of standardized heights were uprooted with the objective of studying their root systems. The lowest densities stimulated higher numbers of first and second order roots as well as fresh and dry matter weights of thin roots with mycorrhizae presence. In both parts of the experiment, the density of 278 seedlings m-2 yielded equivalent averages as compared to the lowest densities.


2019 ◽  
Vol 11 (10) ◽  
pp. 277 ◽  
Author(s):  
Meire Pereira de Souza Ferrari ◽  
Mayara dos Santos Queiroz ◽  
Matheus Marquezini de Andrade ◽  
Jessica Rezende Trettel ◽  
Hélida Mara Magalhães

This study aimed to evaluate the in vitro growth and biochemical activity of Curcuma longa explants using different MS medium formulations and growth regulators. In all the experiments, plants were grown in MS medium supplemented with agar (6.5 g L-1) and pH adjusted to 5.8. In the first assay, the MS culture medium at 70% strength, supplemented with 30 g L-1 of sucrose, and without the addition of activated carbon, resulted in the highest number of shoots. The sucrose concentration of 60 g L-1, combined with the addition of actived charcoalin half-strength MS medium, resulted in the increased root dry mass, root collar diameter, and relative chlorophyll index. In the second assay, the highest root collar diameter and dry matter of shoots and roots were found in the MS medium supplemented with 4.44 BAP, 0.46 KIN, and 1.08 NAA. The MS medium with 8.88 BAP, 0.92 KIN, and 2.16 μM NAA resulted in the highest number of shoots (7.75), number of leaves (35), and shoot length (88.57 mm). The antioxidant activity was significantly higher in the treatments that resulted in better plantlets growth performance, demonstrating that the antioxidant activity is related to other factors such as a possible role of growth regulators on the elicitation of compounds in plants. Superoxide dismutase had a high enzymatic activity in both assays, whereas the enzymatic activity of catalase and ascorbate peroxidase was dependent on the culture media used.


2013 ◽  
pp. 39-50 ◽  
Author(s):  
Vladan Ivetic ◽  
Zoran Davorija ◽  
Dragica Vilotic

Most commonly used morphological attributes were correlated with nutrient concentration in order to standardize quality assessment of two-year-old hop hornbeam (Ostrya carpinifolia Scop.) seedlings. Diameter has proven to be the best single morphological indicator of seedling quality given its strong positive correlation with all other observed morphological attributes. Seedling dry mass (shoot and root dry mass) and Dickson Quality Index can be considered the most comprehensive indicators of hop hornbeam seedling quality. However, the measuring of mass is destructive and requires a certain amount of time. The absence of strong correlations between physiological and morphological attributes of two-year old seedlings of hop hornbeam suggests the need for further research. The only significant correlation between physiological and morphological attributes (weak and positive) was recorded between the potassium concentration in root and root collar diameter after the second growing season.


1985 ◽  
Vol 15 (3) ◽  
pp. 586-592 ◽  
Author(s):  
John L. Ruehle

Loblolly (Pinustaeda L.), longleaf (Pinuspalustris Mill.), shortleaf (Pinusechinata Mill.), and eastern white (Pinusstrobus L.) pine seedlings inoculated with Pisolithustinctorius (Pers.) Coker & Couch (Pt) were raised in a greenhouse in containers painted with latex paint containing 50 g/L cupric carbonate (CuCO3). To determine the effects of CuCO3 on root development and morphology, seedlings were sampled in the middle and at the end of the test. The treatment was effective in preventing most first-order laterals of all species from growing down the container wall, yet it had no significant effect on seedling height, root-collar diameter, or top and root fresh weight. Cupric carbonate had little effect on ectomycorrhizal formation on loblolly and shortleaf seedlings, but significantly increased it on longleaf seedlings and decreased it on eastern white seedlings. Using CuCO3 to alter root morphology of containerized southern pine seedlings inoculated with Pt has the potential for developing stock that will grow long laterals near the soil surface for anchorage and increase the rate of spread of Pt ectomycorrhizae from the plug to new roots after planting.


Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 682 ◽  
Author(s):  
Fenglu Liu ◽  
Pengfei Xu ◽  
Houjiang Zhang ◽  
Cheng Guan ◽  
Dan Feng ◽  
...  

In this study, 145 poplar (Populus × euramericana cv.’74/76’) seedlings, a common plantation tree species in China, were selected and their ultrasonic velocities were measured at four timepoints during the first growth year. After that, 60 poplar seedlings were randomly selected and cut down to determine their acoustic velocity, using the acoustic resonance method. The effects of influencing factors such as wood green density, microfibril angle, growth days, and root-collar diameter on acoustic speed in seedlings and the relationship between ultrasonic speed and acoustic resonance speed were investigated and analyzed in this work. The number of specimens used for investigating growth days and root-collar diameter was 145 in both cases, while 60 and two specimens were used for investigating wood density and the microfibril angle, respectively. The results of this study showed that the ultrasonic speed of poplar seedlings significantly and linearly increased with growth days, within 209 growing days. The ultrasonic velocity of poplar seedlings has a high and positive correlation with growth days, and the correlation was 0.99. However, no significant relationship was found between the ultrasonic velocity and root-collar diameter of poplar seedlings. Furthermore, a low and negative relationship was found between wood density and ultrasonic speed (R2 = 0.26). However, ultrasonic velocity significantly decreased with increasing microfibril angle (MFA) in two seedlings, and thus MFA may have an impact on ultrasonic speed in poplar seedlings. In addition, ultrasonic velocity was found to have a strong correlation with acoustic resonance velocity (R2 = 0.81) and a good correlation, R2 = 0.75, was also found between the dynamic moduli of elasticity from ultrasonic and acoustic resonance tests. The results of this study indicate that the ultrasonic technique can possibly be used to measure the ultrasound speed of young seedlings, and thus early screen seedlings for their stiffness properties in the future.


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