Effects of controlled-release fertilizers on shoot and root development of outplanted western hemlock (Tsugaheterophylla Raf. Sarg.) seedlings

1981 ◽  
Vol 11 (4) ◽  
pp. 752-757 ◽  
Author(s):  
William C. Carlson

Controlled-release fertilizers applied to the root zone of 1-0 plug western hemlock (Tsugaheterophylla Raf. Sarg.) at planting stimulated shoot and root growth in the following two growing seasons. The number and diameter of lateral roots was increased by fertilizing, but fertilizing did not alter the shoot–root ratio. The shoot–root ratio did not increase with an increase in seedling size, height, or total weight.

1981 ◽  
Vol 11 (2) ◽  
pp. 231-243 ◽  
Author(s):  
W. C. Carlson ◽  
C. L. Preisig

Controlled-release fertilizers, applied to the root zone of 1-0 plug Douglas-fir (Pseudotsugamenziesii Mirb. Franco) seedlings at planting, stimulated shoot and root growth in the following two growing seasons. Stem unit length was increased in the first growth flush after treatment, and a higher proportion of fertilized seedlings had a second growth flush that year. Fertilizing increased the number of needle primordia formed in the overwintered bud in the late summer and fall of the 1st year after treatment and increased the number of lateral buds formed the following spring, but did not affect the length of stem units elongated in the first growth flush of the 2nd year after treatment. Shoot–root ratio was not altered abnormally by fertilizing. Fertilizing increased the number and in some cases the diameter of lateral roots in the root system. Position of fertilizer placement did not alter root system symmetry in terms of the distribution of numbers of roots over 12 root zones.


Development ◽  
2020 ◽  
Vol 148 (1) ◽  
pp. dev190033
Author(s):  
Vibhav Gautam ◽  
Archita Singh ◽  
Sandeep Yadav ◽  
Sharmila Singh ◽  
Pramod Kumar ◽  
...  

ABSTRACTRoot system architecture and anatomy of monocotyledonous maize is significantly different from dicotyledonous model Arabidopsis. The molecular role of non-coding RNA (ncRNA) is poorly understood in maize root development. Here, we address the role of LEAFBLADELESS1 (LBL1), a component of maize trans-acting short-interfering RNA (ta-siRNA), in maize root development. We report that root growth, anatomical patterning, and the number of lateral roots (LRs), monocot-specific crown roots (CRs) and seminal roots (SRs) are significantly affected in lbl1-rgd1 mutant, which is defective in production of ta-siRNA, including tasiR-ARF that targets AUXIN RESPONSE FACTOR3 (ARF3) in maize. Altered accumulation and distribution of auxin, due to differential expression of auxin biosynthesis and transporter genes, created an imbalance in auxin signalling. Altered expression of microRNA165/166 (miR165/166) and its targets, ROLLED1 and ROLLED2 (RLD1/2), contributed to the changes in lbl1-rgd1 root growth and vascular patterning, as was evident by the altered root phenotype of Rld1-O semi-dominant mutant. Thus, LBL1/ta-siRNA module regulates root development, possibly by affecting auxin distribution and signalling, in crosstalk with miR165/166-RLD1/2 module. We further show that ZmLBL1 and its Arabidopsis homologue AtSGS3 proteins are functionally conserved.


1995 ◽  
Vol 71 (4) ◽  
pp. 459-465 ◽  
Author(s):  
Alain Cogliastro ◽  
Andrée Hallé ◽  
Michel Labrecque ◽  
Stéphane Daigle

Three types of containers of different volumes (Polymos 15, 700 cm3; Polymos 12, 1,000 cm3; Whitcomb®, 3,500 cm3) were tested to produce large hardwood seedlings. Studies of growth and root development of three species, white ash (Fraxinus americana L.), bur oak (Quercus macrocarpa Michx.) and northern red oak (Quercus rubra L.) were used to assess containers after two growing seasons in an unheated plastic shelter. The mean height of seedlings increased with the volume of the containers. The total dry mass of seedlings at 55 cm in height was more important in the larger container; the total root mass and the proportion of secondary roots were higher in the container of greater volume. For the two species of oak, the 3,500 cm3 container produced seedlings with a taproot showing a number of deviations when touching the bottom of the container. White ash, a species with a fibrous root system, showed a higher deviation index in the smaller containers. The openings on the sides of the square-shaped Whitcomb® containers were effective for the air-pruning of secondary lateral roots of species with a taproot and their volume allowed for an important root mass. However, the flat bottom with openings at each of the four corners did not prevent deviation of the primary root. The use of a bottomless square-shaped container with a volume greater than 1,000 cm3 and with adequate lateral openings would optimize the production of large seedlings of hardwood species with taproot. Key words: large containerized seedlings, root development, root deviation, Quercus sp., Fraxinus sp.


2021 ◽  
Author(s):  
Stella F. Valle ◽  
Amanda S. Giroto ◽  
Gelton G. F. Guimarães ◽  
Kerstin A. Nagel ◽  
Anna Galinski ◽  
...  

In face of the alarming world population growth predictions and its threat to food security, the development of sustainable fertilizer alternatives is urgent. Moreover, fertilizer performance should be assessed not only in terms of yield but also root system development, as it impacts soil fertility and crop productivity. Fertilizers containing a polysulfide matrix (PS) with dispersed struvite (St) were studied for S and P nutrition due to their controlled-release behavior. Soybean cultivation with St/PS composites provided superior biomass compared to a reference of triple superphosphate (TSP) with ammonium sulfate (AS), with up to 3 and 10 times higher mass of shoots and roots, respectively. Additionally, St/PS achieved a 22% sulfur use efficiency against only 8% from TSP/AS. Root system architectural changes may explain these results, with higher proliferation of second order lateral roots in response to struvite ongoing P delivery. Overall, the composites showed great potential as efficient controlled-release fertilizers for enhanced soybean productivity.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1026C-1026
Author(s):  
Shengrui Yao ◽  
Ian A. Merwin ◽  
Michael G. Brown

Rhizotron observations enabled us to compare the performance of three apple (Malu ×domestica) rootstock clones following different pre-plant soil treatments in an apple replant study at Ithaca, NY. Trees were planted in Nov. 2001, with one minirhizotron tube per tree in three replicate plots of three rootstocks (M7, CG30, and CG6210), three pre-plant soil treatments (fumigation, compost amendment, and untreated controls), and two planting positions (within the old tree rows, or in the old grass lanes). Monthly root observations were conducted during the 2003 and 2004 growing seasons. There were substantially fewer new roots observed in the first bearing year (2004) than the previous nonbearing year (2003), for all three rootstocks. A root-growth peak in early July accounted for more than 50% of all new roots in 2003, but there was no midsummer root growth peak in 2004. Neither pre-plant soil treatments nor old row or grass-lane planting positions had much influence on root growth. The median lifespan for roots of CG6210 was twice as long as that of CG30 and M7 in 2004. Also, CG6210 had more roots below 30-cm depth, while M7 had more roots from 11–20 cm. Trees grafted on CG6210 were bigger and yielded more fruit in the third year after planting, compared with trees on CG30 and M7 rootstocks. Crop load severely inhibited new root development and changed root-growth dynamics during the first cropping year, with a surge in root growth after fruit harvest in Oct. 2004. Rootstock genotype was the dominant influence on root lifespan and distribution, compared with pre-plant soil fumigation, compost amendments, or replanting positions within the previous orchard rows or grass lanes.


1969 ◽  
Vol 9 (39) ◽  
pp. 445 ◽  
Author(s):  
RA Bray ◽  
JB Hacker ◽  
DE Byth

Root growth patterns of Glycine javanica, Setaria anceps, and Medicago sativa were studied by uptake of 32P from a sandy loam. Placement of isotope was through permanently positioned PVC conduit on a grid over a 90� quadrant of the root system. Detection of radioactivity was in in situ plant material. Lucerne had strong initial root development but was slow to form lateral roots. Glycine and Setaria had quite similar root systems although Setaria had more rapid vertical root development than Glycine. Both these species had strong lateral root systems. When a regression of minimum root length against time was calculated, lateral root growth was shown to be independent of depth and distance from the plant, suggesting that roots behave as if growing from a point source in random directions at a constant rate. This rate was the same for all species. There were also indications of strong vertical root systems in lucerne and Setaria.


2005 ◽  
Vol 35 (11) ◽  
pp. 2642-2654 ◽  
Author(s):  
C Krause ◽  
H Morin

Black spruce (Picea mariana (Mill.) BSP) and balsam fir (Abies balsamea (L.) Mill.) are the two main tree species in the boreal forests of Quebec, Canada, and both show adventive-root formation. Little is known about the dynamics of adventive-root initiation and the pattern of length growth. To gain a better understanding of root growth, the root systems of 30 mature black spruce and 30 mature balsam fir were excavated until the root diameter had decreased to 2 cm. Tree ages ranged from 100 to more than 250 years. All trees showed only adventive roots; this was confirmed by dating the root–shoot interface. The youngest lateral roots were located close to ground level, whereas the oldest ones occurred lower in the stump, suggesting a process of renewal for the latter. Reconstruction of the development of the root system revealed a specific root-growth pattern. Adventive roots grew, on average, more than 60% of their total length in the year of initiation, whereas more than 93% of lateral-root elongation was recorded in the first 10 years after adventive roots were initiated. This growth pattern was found to be similar in the two tree species in terms of lateral-root development (p = 0.68). More variability was observed for the ramified adventive roots. However, two patterns emerged. First, around 10% of total elongation was completed in the same year as that of the corresponding lateral roots. Second, several ramified adventive roots were initiated in the same calendar year but delayed by several years relative to lateral adventive root initiation. No significant differences were observed between black spruce and balsam fir (p = 0.1).


1979 ◽  
Vol 30 (4) ◽  
pp. 587 ◽  
Author(s):  
L O'Brien

Ten wheat genotypes were examined for their pattern of root development in glass-fronted growth containers in the greenhouse. Differences between genotypes were recorded in the number of first-order lateral roots at 2,3 and 4 weeks' growth, the number of second-order lateral roots, the maximum depth of penetration, and the angle between the seminal root axes at 4 weeks' growth and the length of lateral root per 10 cm depth increment at 5 weeks' growth. Significant positive correlations existed between many of the seminal root parameters. Differences between genotypes in the length of nodal root axes were recorded at 7 and 8 weeks' growth. Nodal root length was influenced by tiller number and the rate of tiller initiation. Tiller development, and consequently root growth, was related to plant phasic development. Genetic modification of seminal root development appears possible, with the direction of selection depending on the definition of an optimum root development pattern.


2022 ◽  
pp. 59-66
Author(s):  
T. M. DeJong

Abstract Root development and growth is similar to shoot growth in that extension growth is initiated by an apical meristem and girth growth of mature roots is carried out by the vascular cambium. However, the initiation of lateral roots is entirely different than the initiation of lateral leaves or shoot meristems. This chapter deals with understanding the root sink in fruit trees by studying root growth, including the initiation of lateral roots, root classification according to size and function, factors affecting their growth, and rootstocks.


1998 ◽  
Vol 16 (3) ◽  
pp. 182-188
Author(s):  
Kelly M. Groves ◽  
Stuart L. Warren ◽  
Ted E. Bilderback

Abstract Rooted cuttings of Cotoneaster dammeri Schneid ‘Skogholm’ and seedlings of Rudbeckia fulgida Ait. ‘Goldsturm’ were potted into 3.8 liter (4 qt) containers in a pine bark:sand (8:1 by vol) substrate incorporated with 3.5 g (0.12 oz) N per container provided by one of the following five controlled-release fertilizers (CRFs): Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Two hundred ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) or 1200 ml (1.7 in) of water was applied once daily (single) or in two equal applications with a 2 hr interval between applications (cyclic). Substrate solutions were collected from containers of cotoneaster 15, 32, 45, 60, 74, 90, 105, and 119 days after initiation (DAI). Irrigation efficiency [(water applied − water leached) ÷ water applied] was determined on the same days. Cyclic application improved irrigation efficiency at 800 ml (1.1 in) and 1200 ml (1.7 in) ≈ 27% compared to a single application. Irrigation efficiencies averaged over the season were 95%, 84%, 62%, and 48% for cotoneaster and 100%, 90%, 72%, and 51% for rudbeckia at 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) and 1200 ml (1.7 in), respectively. NH4-N and NO3-N and PO4-P concentrations in substrate solution decreased with increasing irrigation volume regardless of CRF. Substrate NH4-N concentration decreased throughout the season with most CRFs below 5 mg/liter by 90 DAI. CRFs mainly affected substrate NH4-N and NO3-N concentrations when irrigated with 200 ml (0.3 in) or 400 ml (0.6 in). Substrate NH4-N, NO3-N, and PO4-P solution concentrations were similar for all CRFs at irrigation volume of 1200 ml (1.7 in). Osmocote, Scotts, and Woodace maintained relatively constant substrate solution levels of PO4-P through 60 DAI. By 90 DAI, substrate PO4-P levels were similar regardless of irrigation volume or CRF. Substrate PO4-P concentrations were never in the recommended range of 5 to 10 mg/liter when irrigated with 800 ml (1.1 in) or 1200 ml (1.7 in) regardless of CRF. Solution pH remained in the recommended range of 5.0 to 6.0 for all irrigation volumes and CRFs throughout the entire study with the exception of Sustane.


Sign in / Sign up

Export Citation Format

Share Document