scholarly journals Effects of Root Pruning on Germinated Pecan Seedlings

HortScience ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 1549-1552 ◽  
Author(s):  
Rui Zhang ◽  
Fang-Ren Peng ◽  
Pan Yan ◽  
Fan Cao ◽  
Zhuang-Zhuang Liu ◽  
...  

Root systems of pecan trees are usually dominated by a single taproot with few lateral roots, which are commonly thought to inhibit successful transplanting. This study aimed to evaluate early growth and root/shoot development of pecan seedlings in response to taproot pruning. Taproots of ‘Shaoxing’ seedling pecan trees were mildly (1/3 of the total length of the radicle removed) and severely (2/3 of the total length of the radicle removed) pruned at different seedling development stages shortly after germination. At the end of the first growing season, top growth was measured and then trees were uprooted so that root system regrowth could be evaluated. The results showed that root pruning had no impact on increases in stem height or stem diameter. However, pruning the taproot could stimulate primary growth in taproot branches. Root weight and the number of taproot branches per tree increased with decreasing taproot length. This study indicated that severe root pruning when three to five leaves had emerged resulted in root systems with more taproot branches and the greatest root dry weight after one growth season, which may increase survival and reduce transplanting shock.

1979 ◽  
Vol 9 (3) ◽  
pp. 311-315 ◽  
Author(s):  
Isabel F. Alvarez ◽  
David L. Rowney ◽  
Fields W. Cobb Jr.

White fir (Abiesconcolor (Gord. et Glend.) Lindl.) seedlings appear to survive and grow better in mineral soil alone than in mineral soil with organic layers. To determine whether the better growth observed in seedlings in mineral soil (M), compared with those in mineral soil with organic layers (MO), could be related to the incidence of mycorrhizae in their root systems, natural M and MO seedlings were examined from five sites in the north central Sierra Nevada. Statistical analysis of the data showed that seedling dry weight was significantly related to total length of roots, number of main lateral roots, and presence of mycorrhizae on the roots. Dry weight, total length of roots, total number of mycorrhizal tips, and number of mycorrhizal tips per centimetre of roots were significantly higher for M compared with MO seedlings. Age, number of main lateral roots, and number of mycorrhizal tips per centimetre of roots are highly significant in distinguishing M from MO seedlings. The data indicate that mycorrhizae play an important role in the growth of white fir seedlings, and that both growth and presence of mycorrhizae are favored by the absence of organic layers.


2011 ◽  
Vol 35 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Mary Anne Sword Sayer ◽  
Shi-Jean Susana Sung ◽  
James D. Haywood

Abstract Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling size, the allocation of root system dry weight to the taproot, and the fraction of fibrous root mass allocated to secondary lateral roots compared with primary lateral roots. It decreased the allocation of root system dry weight to primary lateral roots and led to a distribution of root growth potential that more closely resembled the root growth of naturally sown seedlings. These effects of copper root pruning may benefit longleaf pine establishment. However, because copper root pruning increased competition for cavity growing space among the taproot and fibrous roots, we suggest that recommendations regarding cavity size and seedling quality parameters be tailored for copper-coated cavities.


1972 ◽  
Vol 2 (3) ◽  
pp. 223-227 ◽  
Author(s):  
S. Eis ◽  
J. R. Long

Roots of Sitka spruce (Picea sitchensis) and western hemlock (Tsugaheterophylla) seedlings were side pruned in nursery beds at semimonthly intervals to produce dense and compact root systems. Root pruning early in the growing season stimulated the growth of existing roots and also initiated new roots. The densest root systems were produced by pruning before the end of June. However, because of the short length of lateral roots on seedlings early in their second growing season, pruning equidistant between rows 18 cm apart was ineffective. The best compromise appeared to be to prune spruce at the beginning of July, and hemlock around the middle of July. Earlier pruning equidistant between rows can be effective on larger seedlings during their third growing season. If early pruning is carried out on 2 + 0 seedlings, a pruning distance of about 6 cm from the row is recommended.


2002 ◽  
Vol 20 (2) ◽  
pp. 127-132
Author(s):  
Edward F. Gilman ◽  
Ann Stodola ◽  
Michael D. Marshall

Abstract Cutting propagated Quercus virginiana ‘QVTIA’ Highrise™ PP #11219 and seedling live oak required the same amount of time to prune to a dominant leader in the nursery. Highrise™ live oaks were more uniform in caliper, height and root ball characteristics than the seedling crop. Finished seedling trees had larger caliper than cutting propagated Highrise™ but height was similar. Root pruning horizontal roots alone or in combination with placing root pruning fabric under the liner at planting reduced dry weight of roots in the root ball by reducing large-diameter root weight and increasing small-diameter root weight. Trees produced by both methods of root pruning survived the digging process better than non root-pruned trees in the summer digging season. Seedlings had more root weight in the root ball and a higher root: shoot ratio than Highrise™ live oak. But Highrise™ had a 45% greater small diameter root: shoot ratio than seedling live oak, and more Highrise™ survived the digging process than seedlings. Highrise™ may not need root pruning during production if dug in the dormant season.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 471b-471
Author(s):  
Jim E. Wyatt

The objectives of this study were to investigate the effects of trifluralin (TRI) herbicide on plant vigor and lateral root growth of snap beans. Lexington silt loam soil, which had not been treated with herbicides for at least 3 years, was used in this study. TRI herbicide was mixed with appropriate amounts of soil in a cement mixer to provide a constant rate of 560 g ai/ha TRI. To simulate TRI herbicide incorporation, bands of treated and untreated soil were layered into 30 × 30 × 15 cm (vol 13,500 cm3) bottomless wood boxes. Treatments were 1) control, 2) 2.5-cm treated band placed 2.5 cm below soil surface (BSS), 3) 2.5 cm treated band placed 5.1 cm BSS, 4) top 5.1 cm with treated soil, or 5) top 7.6 cm with treated soil. `Benton' snap beans were planted in each box and grown in the greenhouse for 25 days. Plant measurements made included plant height, leaf area, and fresh and dry weight. The root system of each plant was washed and roots arising from the hypocotyl, transition zone, and primary roots were counted. All roots from each box were combined, dried overnight at 100C and weighed. Plant top weight and leaf area were not affected by TRI treatments. Plants were shorter in all TRI treatments except where placement was banded at 5.1 cm BSS. More adventitious roots were produced on hypocotyls when TRI was applied in a 2.5-cm band at 2.5-cm BSS or in the top 5.1 cm of soil. Total root weight was lower and fewer lateral roots developed in all soil bands treated with TRI.


Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 687-702
Author(s):  
Milica Blazic ◽  
Dejan Dodig ◽  
Vesna Kandic ◽  
Dragoslav Djokic ◽  
Tomislav Zivanovic

The evaluation of the embryonic root and stem of bread wheat (Triticum aestivum L.) in the early stage of development (seedling stage) can be a powerful tool in wheat breeding aimed at obtaining progenies with a greater early vigour. It is revealed that genotypes with faster early vigour have produced higher biomass and grain yield. In this study, the evaluation of traits of the embryonic root and the embryonic stem of 101 bread wheat genotypes was preformed at the 10-day old seedlings. The following eight morphological traits of roots and stems were analysed: primary root length, branching interval, the number of roots, total length of lateral roots, angle of seminal roots, stem length, root dry weight and the stem dry weight. Analysed lateral roots included seminal roots. The greatest, i.e. the smallest variability of observed traits was detected in the branching interval, i.e. the stem length, respectively. The highest positive correlation was determined between the primary root length and the total length of lateral roots. The cluster analysis, based on observed traits, shows that genotypes were clearly divided into two main clusters, A and B. The two clusters essentially differed from each other in the values of the following traits: primary root length, total length of lateral roots, root dry weight, stem dry weight and the stem length. Genotypes with shorter primary and lateral roots, lower root and stem dry weight and a shorter stem were grouped in the cluster B. On the other hand, the cluster A encompassed genotypes with values of these traits above or around the average. The values of the remaining analysed traits: the angle of seminal roots, the number of lateral roots and the branching interval varied greatly between obtained clusters. The cluster analysis showed the homogeneity of genotypes originating from Serbia and the region; their values of the root and stem length and weight were mostly around and below the average. However, the values of the angle of seminal roots, number of lateral roots and the branching interval were above average.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 607f-607
Author(s):  
Daniel G. Krueger ◽  
Bert T. Swanson

To increase root fibrosity, acorns of northern red oak (Quercus rubra L.) were germinated and subjected to several radicle clipping (+/-) and K-IBA concentration treatments combintations prior to planting. Taproots and laterals ≥ 1 mm in diameter at the point of origin were counted. Low concentrations of K-IBA (0-4000 ppm) resulted in four root morphologies: 1) a single taproot and 3-6 laterals (no clipping/no K-IBA), 2) 4-5 taproots and 1-3 laterals (clipped only), 3) a single taproot and 5-12 laterals (not clipped/K-IBA) and 4) 6-12 taproots and 1-2 laterals. High concentrations of K-IBA (4000-10,000 ppm) `clipped' unclipped radicles resulting in root systems similiar to those clipped by hand. Stem height was unaffected by treatment. Radicle-clipping may increase stem caliper. K-IBA treatments may decrease root dry weight.


Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 966-971 ◽  
Author(s):  
Loke T. Kok ◽  
Thomas J. McAvoy ◽  
Warren T. Mays

Field plot experiments were conducted to examine the interactions between tall fescue grass (Festuca arundinaceaSchreb.), musk thistle (Carduus nutansL. =thoermeriWeinmann # CRUNU), and two thistle weevilsTrichosirocalus horridus(Panzer) andRhinocyllus conicusFroelich. Restriction of musk thistle growth was greatest when the weevils were allowed to feed on the musk thistles competing with tall fescue. Significant reductions were found in total musk thistle seeds per plant, root weight, flower buds per plant, stem dry weight, seeds per head, root crown diameter, stem height, rosette diameter, and head diameter. Seed weight and viability were not reduced. Of the three stress factors (tall fescue and the twoCarduusthistle weevils), tall fescue had the greatest impact. When musk thistle seeds were planted in 1-yr-old tall fescue, germination was low. Seeds that germinated did not grow more than four Leaves and none of the thistles developed to the reproductive stage. A 1-year-old tall fescue stand effectively prevented musk thistle reproduction. Thus, tall fescue helped suppress musk thistle growth more quickly than the use ofCarduusthistle weevils alone without competitive vegetation. Dry weight of tall fescue grass was lower in musk thistle-infested plots than in the thistle-free plots.


1991 ◽  
Vol 69 (6) ◽  
pp. 1170-1178 ◽  
Author(s):  
Elida Stasovski ◽  
Carol A. Peterson

Drought was induced in Turface and vermiculite-grown seedlings of Zea mays L. by withholding water. Despite a 34-day drought period, the roots of stressed plants increased in dry weight by continued elongation of existing roots and initiation of new roots. A differential response to desiccation, with respect to structure and cell vitality, was observed along the root axes. In apical regions (terminal 20 mm) of seminal roots, all cell layers typically remained alive. In midlength regions (half way between the apex and base), the epidermis died in both control and treatment plants. The cortex of control roots displayed some distortion, but most of the cells were alive; the cortex of stressed roots displayed severe collapse and death of the majority of these cells. In basal regions (20 mm distal to the kernel), cells of the outer cortex were sclerified and less susceptible to collapse. Cells of stelar tissues retained their normal shapes and vitality. Upon rehydration, the root systems of stressed plants resumed growth by elongation of existing seminal, adventitious, and lateral roots and, in some cases, also by emergence of previously dormant lateral root primordia. The root systems' capacity for recovery diminished with increasing stress. Key words: drought, roots, Zea mays L., exodermis, hypodermis.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 419C-419
Author(s):  
T.J. Tworkoski ◽  
R. Scorza

Peach trees (Prunus persica L.) with diverse shoot growth habits have been developed, but little is known about their root systems. Characterizing shoot and root systems can improve basic understanding of peach tree growth and be important in the development of rootstocks and own-rooted trees. This research determined shoot and root characteristics of four peach tree growth habits (compact, dwarf, pillar, and standard). Seed from four peach growth habits were planted in 128-L containers, grown outside during the 1998 growing season, and then harvested. Compact tree leaf number (1350/tree) was twice, but leaf area (6 cm2/leaf) was half, that of pillar and standard trees. The number of lateral branches in compact trees (34) was nearly three-times more than in pillar and standard trees. The leaf area index (LAI) of pillar trees was greater than compact and standard trees (13 compared with 4 and 3, respectively) due to a narrower crown diameter. Dwarf tree shoots were distinct with few leaves (134 per tree) and a large LAI of 76. Compact trees grew more higher-order lateral roots than pillar and standard trees. More second-order lateral (SOL) roots were produced by compact than standard trees (1.2 vs. 0.8 SOL roots/cm first-order lateral root). Pillar trees had higher shoot-to-root dry weight ratios (2.4) than compact and standard trees (1.7 for both) due to smaller root dry weights. The results indicate fundamental differences in root characteristics among the peach tree growth habits. Compact trees had more higher order lateral roots in roots originating near the root collar (i.e., more fibrous roots), and this correlated with more lateral branches in the canopy. Shoot weights were the same among pillar, compact, and standard trees but root weights were less in pillar trees, resulting in greater shoot-to-root dry weight ratios. These results indicate significant differences in root as well as shoot architecture among growth habits that can affect their use as scion or rootstock varieties.


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