Relationship between spacing and nitrogen fertilization of seedlings in the nursery, seedling size, and outplanting performance

1982 ◽  
Vol 12 (4) ◽  
pp. 865-875 ◽  
Author(s):  
R. van den Driessche

Nursery sowings of coastal and interior varieties of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), Sitka spruce (Piceasitchensis (Bong) Carr), and lodgepole pine (Pinuscontorta Dougl.) were thinned to different spacings 5 weeks after germination. Spacings in the drills, which were 15 cm apart, were 1, 2, 4, 8, and 12 cm, with the nursery sowing rate (about 0.6-cm spacing) as control. Spacings were applied factorially with three levels of N fertilizer: 60, 140, and 235 kg N ha−1. Two-year-old seedlings were planted out at Campbell River (coastal Douglas-fir) and Port Alice (Sitka spruce), both on Vancouver Island, and at Lyne Creek (interior Douglas-fir) in the Cariboo region and at Fulton Lake (lodgepole pine) in the Prince Rupert region of British Columbia. Wider spacing and greater N supply increased 2-0 seedling dry weight, root-collar diameter, and shoot height and also affected distribution of dry matter between needles, stems, and roots. Wider spacing increased survival of outplanted interior Douglas-fir by 12%. Survival of coastal Douglas-fir and Sitka spruce species was high and only increased 4 to 7% due to wide spacing after one season, but after three seasons wide spacing increased survival 17 – 19%. Compared with control, 12-cm spacing increased first-season shoot growth 53% for coastal Douglas-fir, 82% for interior Douglas-fir, and 71% for Sitka spruce. Second-season shoot growth of lodgepole pine was increased 92% by the widest spacing. Much of the improved growth was explained in terms of increased seedling size. At the highest level of N supply, increasing spacing to 4 cm did not greatly reduce yield of seedlings with root-collar diameters greater than 3 mm, except for interior Douglas-fir. Thus moderate increase in spacing improved quality without materially reducing yield of seedlings per unit area of nursery. Nursery fertilization at 235 kg N ha−1 increased new-shoot growth one season after planting by 36–58% compared with the 60 kg N ha−1 level. After three seasons the effect of higher N supply was reduced to 0–42%. High N level increased survival of coastal Douglas-fir and Sitka spruce slightly, but decreased survival of interior Douglas-fir.

1984 ◽  
Vol 60 (6) ◽  
pp. 345-355 ◽  
Author(s):  
R. van den Driessche

In three experiments coastal and interior varieties of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Sitka spruce (Picea sitchensis (Bong.) Carr), white spruce (Picea glauca (Moench.) Voss), lodgepole pine (Pinus contorta var. latifolia Engelm) and western red cedar (Thuja plicata Donn.) were grown at a range of spacings, within drills 15 cm apart, at four nurseries in coastal British Columbia. In a fourth experiment the frequency distribution of seed spacings achieved with three types of precision seeders was examined.A 1 cm increase in spacing increased seedling dry weight by 0.5–1.5 g and root collar diameter by 0.2–0.25 mm. up to a spacing of about 8–10 cm. Above this spacing response was less. Height of two-year old (2-0) seedlings was increased little, or even decreased by wider spacing. Height:diameter ratios decreased sharply and shoot:root dry weight ratios decreased or remained unchanged with wider spacing. The number of needle primorida in 2-0 Douglas-fir buds increased up to a spacing of 2 cm. The number of first and second order branches was also increased in 2-0 seedlings of this species by wider spacing. Needle dry weight and area measurements suggested Douglas-fir from wider spacing had more sun type needles than those from closer spacing, which had more shade type needles. Only small increases in root growth capacity (RGC) were associated with wider spacing. None of the precision seeders tested achieved anything like perfect precision of seed placement. With irregularity added by 10–20% non-viable seed and winter mortality, truly precision spaced stands of 2-0 seedlings could not be achieved under existing conditions. Increased spacing of 2–5 cm between seedlings, depending on species and nursery, was justified by yield of acceptable seedlings when culling standard was increased to a root collar diameter of about 6 mm.Three years after planting, survival of white spruce was increased 11% by wider spacing in the nursery, and the corresponding value for Sitka spruce two years after planting was 13%. Seedlings of both species from wider spacings maintained a height and diameter advantage over those from close spacing.


1984 ◽  
Vol 14 (3) ◽  
pp. 431-436 ◽  
Author(s):  
R. van den Driessche

Three nitrogen (N) levels and six seedling spacings were applied factorially in a randomized block design, of four replications, to coastal and interior varieties of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), Sitka spruce (Piceasitchensis (Bong.) Carr), and lodgepole pine (Pinuscontorta Dougl.) in the nursery. After growing for 2 years in the nursery, seedling dimensions, dry weights, and needle N, phosphorus (P), and potassium (K) concentrations were determined. At the same time, samples of 400 trees per treatment were planted into the forest using the nursery design. Three years after outplanting, survival and height measurements were obtained for all species and, in addition, dry weights and nutrient concentrations for the coastal Douglas-fir. Both an increase in N fertilizer and wider spacing increased 2-year-old (2–0) seedling needle percent N, except in lodgepole pine. Wider spacing also increased percent P in interior Douglas-fir and percent K in lodgepole pine. Within the highest N fertilizer level the amount of variation in needle percent N accounted for by spacing was 75% in coastal Douglas-fir, 78% in interior Douglas-fir, and 92% in Sitka spruce. Needle percent N in 2–0 coastal Douglas-fir and Sitka spruce was positively correlated with survival (r2 = 0.24 and 0.35, respectively), total height (r2 = 0.48 and 0.61, respectively), and current height growth (r2 = 0.31 and 0.51, respectively) after 3 years in the forest. The relationships of spacing to 2–0 seedling percent N, and of 2–0 seedling percent N to outplanting performance indicated that, at least for Douglas-fir and Sitka spruce, spacing influenced outplanting performance through its effect on N nutrition. During 3 years in the forest, coastal Douglas-fir trees had maintained closely similar relative growth rates (RGR) in all treatments. Consequently, relative differences in 2–0 seedling dry weight between treatments of about threefold between 0.6- and 12-cm spacing and twofold between 60 and 235 kg N/ha fertilizer levels, had been maintained. After 3 years in the forest there were no differences in nutrient concentrations between nursery N treatments, indicating that reserves available at lifting had been dissipated, but nutrient concentrations tended to decrease with wider spacing. This suggested some unidentified wide spacing effect was promoting growth and causing nutrient dilution in the tissue.


2001 ◽  
Vol 31 (2) ◽  
pp. 246-260 ◽  
Author(s):  
Hua Chen ◽  
Mark E Harmon ◽  
Robert P Griffiths

Decomposition of woody roots in Sitka spruce (Picea sitchensis (Bong.) Carrière), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) dominated forests in Oregon, U.S.A. was studied using a chronosequence. Roots of five coniferous species were excavated from stumps with ages up to 46 years old. In order of increasing decomposition rate constant (k) the species were Douglas-fir < Sitka spruce < lodgepole pine (Pinus contorta Dougl. ex Loud.) < western hemlock (Tsuga heterophylla (Raf.) Sarg) < ponderosa pine. Variation in the proportion of bark, wood, and resin cores was correlated to these differences. Root wood showed the highest k, root bark the second, and resin cores the lowest. The occurrence of resin cores in woody roots of Douglas-fir, Sitka spruce, and lodgepole pine greatly slowed the decomposition of these species. White rots occurred frequently in ponderosa pine and lodgepole pine, whereas brown rots mostly appeared in Douglas-fir and Sitka spruce. Species with white rot had a higher k than those with brown rot. Decomposing woody roots started to release N after 20–30% mass loss, a point when the dead root C/N ratio averaged 140.


1993 ◽  
Vol 41 (4) ◽  
pp. 327-341
Author(s):  
P.H.B. De Visser ◽  
W.G. Keltjens

Two pot trials were conducted on effects of soil acidification and excess ammonium on root and shoot development of juvenile Douglas fir (Pseudotsuga menziesii) on an acid sandy forest soil. Experiment I included a control treatment (without fertilizer application) and different supply rates of NH4. Application of other nutrients to the NH4-fertilized pots was constant, while at one supply level the added N included 50% nitrate in order to study effect of N form. High supply rates of ammonium suppressed root length growth, but did not affect shoot growth during one season of application. Root and stem growth was stronger with a mixture of ammonium and nitrate than with pure ammonium as N source. Experiment II examined balanced fertilization, additional to nitrogen, at low and high NH4-N supply during a two-year period. Second year bud break was retarded and shoot growth depressed at high levels of ammonium supply. In August of the second year nearly all trees died that had received a total NH4-N dose of 230 kg/ha. Addition of base cations and P to ammonium application raised P and K needle concentrations, but could not prevent adverse effects of NH4, and even increased acidification of soil. In both experiments presence of a litter layer tended to increase tree growth, and alleviated adverse effects of ammonium in soil and needles. A corresponding fertilizer application in a mature Douglas fir stand on the same soil improved nutrition of P and K as well.


2001 ◽  
Vol 19 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Wallace G. Pill ◽  
James A. Gunter

Abstract This study was conducted to determine whether treating seeds of ‘Sensation Mixed’ cosmos (Cosmos bipinnatus Cav.) and ‘Bonanza Gold’ marigold (Tagetes patula L.) with paclobutrazol (PB) could suppress seedling growth. Seeds were soaked in solutions of 0, 500 or 1000 mg PB/liter (ppm PB) for 16 hours at 25C (77F) or they were primed [−0.5 MPa (−5 bars) for 7 days at 20C (68F)] in Grade 5 exfoliated vermiculite moistened with 0, 500 or 1000 ppm PB solltuions. Soaked and primed seeds were dried for 1 day at 19C (65F) and 25% relative humidity. These seeds and control (non-treated) seeds were sown into plug cells containing peat-lite. Increasing PB concentration decreased cosmos shoot height at 32 days after planting (DAP), but decreased emergence percentage, responses that were more pronounced with priming than with soaking. A 1 ppm PB growth medium drench [30 ml/cell(0.2 mg PB/cell)] and, to a greater extent a 10 mg PB/liter (ppm PB) shoot spray [2 ml/shoot (0.02 mg PB/shoot)], both applied at 10 DAP, resulted in greater cosmos shoot height suppression at 32 DAP than treatment of seeds with 1000 ppm PB. Soaking marigold seeds in 1000 ppm PB failed to decrease shoot height below those of plants from non-treated seeds at 32 DAP. However, exposure to 1000 ppm PB during priming of marigold seeds resulted in a similar shoot height suppression (13%) as the growth medium drench, and similar shoot dry weight reduction (21%) as the shoot spray. Suppression of shoot growth by this seed treatment was short-term since by five weeks after transplanting into 15 cm (6 in) pots, only marigold plants that had received the growth medium drench or shoot spray were smaller than those of control plants. Treating marigold seeds with 1000 mg ppm PB used about one-fifth the PB used to drench the growth medium.


1989 ◽  
Vol 19 (10) ◽  
pp. 1322-1329 ◽  
Author(s):  
G. H. Mohammed ◽  
K. R. Patel ◽  
W. E. Vidaver

Rooting percentage and root number in tissue-cultured Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were influenced by the rooting substrate, the concentration of sucrose and boron in the rooting medium, shoot height, and shoot generation. Peat–perlite was a better substrate than agar, producing 70% compared with 0% rooted shoots, respectively. On peat–perlite, cell divisions were organized and were associated with tracheid nests, whereas on agar proliferation was unorganized and not restricted to the nests. A sucrose concentration of 4% was optimal for the production of nodular or rooted shoots. At 4% sucrose and 3 mg •L−1 boric acid, 100% of the shoots rooted, and the mean root number was 11. Rooting percentage and root number were significantly higher with shoots that were 3 cm tall than 2 or 1 cm tall shoots. Finally, it was found that shoot responses were more rapid in third and fourth generation shoots than in second generation shoots. At least 80% were rooted or nodular after 4 weeks, compared with only 36% from the second generation.


Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 271-275 ◽  
Author(s):  
George Marshall

The growth and development of field horsetail (Equisetum arvenseL. # EQUAR) was measured outdoors using potted plants grown from one-node rhizome fragments. Shoot growth rate increased slowly after planting in March, accelerating to a maximum during July with maximas for shoot height during August and shoot number in September. Rhizome system growth rates initially followed a similar pattern to that of the shoots achieving a maximum during July. Dry matter accumulated in the rhizomes until October and declined thereafter throughout the winter. Tubers initiated during August grew in size and number until November, well beyond the period of active shoot growth and onset of senescence. The characteristics of the growth and development of field horsetail are discussed in relation to achieving weed control via cultural and herbicide treatments.


2019 ◽  
Vol 49 (11) ◽  
pp. 1471-1482
Author(s):  
Woongsoon Jang ◽  
Bianca N.I. Eskelson ◽  
Louise de Montigny ◽  
Catherine A. Bealle Statland ◽  
Derek F. Sattler ◽  
...  

This study was conducted to quantify growth responses of three major commercial conifer species (lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco), and spruce (white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex. Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière))) to various fertilizer blends in interior British Columbia, Canada. Over 25 years, growth-response data were repeatedly collected across 46 installations. The fertilizer blends were classified into three groups: nitrogen only; nitrogen and sulfur combined; and nitrogen, sulfur, and boron combined. The growth responses for stand volume, basal area, and top height were calculated through absolute and relative growth rate ratios relative to a controlled group. Fertilizer blend, inverse years since fertilization, site index, stand density at fertilization, and their interactions with the fertilizer blend were used as explanatory variables. The magnitude and significance of volume and basal area growth responses to fertilization differed by species, fertilizer-blend groups, and stand-condition variables (i.e., site index and stand density). In contrast, the response in top height growth did not differ among fertilization blends, with the exception of the nitrogen and sulfur fertilizer subgroup for lodgepole pine. The models developed in this study will be incorporated into the current growth and yield fertilization module (i.e., Table Interpolation Program for Stand Yields (TIPSY)), thereby supporting guidance of fertilization applications in interior forests in British Columbia.


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