Performance of height-classified Eucalyptus camaldulensis seedlings after one year in the field

Eucalyptus camaldulensis seedlings of 16–25, 26–35, 36–45 and 46–55cm height classes were used to examine the effect of planting stock quality on field performance. Survival, height and diameter (10cm above ground) were assessed 6 and 12 months after planting out. Significant height differences (P 0.05) existed between the 16–25 and 46–55cm height classes at 6 months age. There were no significant (P 0.05) differences in all these parameters at 12 months after planting out throughout the four height classes. It is concluded that the height classification approach for E. camaldulensis seedlings has very little value if the seedlings are in the 16–55cm height range. Until other nursery stock grading approaches are studied, 16–25cm seedling height class is as effective as the taller ones and would therefore be more economical for dry zone afforestation in Malawi.     

Growth,flowering and fruiting of stecklings,grafts and seedlings of <Emphasis Type="Italic">Allanblackia floribunda</Emphasis> Oliver (Clusiaceae)

A study was carried out to assess the growth, flowering and fruiting of stecklings (rooted cuttings), grafts and seedlings of Allanblackia floribunda in Cameroun. Thirty-one individuals of each plantlet type were planted in May 2006. Height, collar and crown diameters were recorded in September and October, while flowering and fruiting were recorded each month from January to December. In 2014, the trees with the greatest height were those from seeds (6.98 ± 0.25 m), followed by those from grafts (1.65 ± 0.23 m) and cuttings (1.09 ± 0.21 m). Grafts started flowering and fruiting 3 years after planting, while seedlings started flowering and fruiting after four and 6 years, respectively. Stecklings still had not flowered 8 years after planting. Fruit weight and length from seed-origin trees are about seven times higher than grafts. Correlations between height and crown diameter were significant and positive irrespective of the nature of the planting material. In conclusion, grafts fruited earlier, while seedlings grew faster and had greater yields than grafts and stecklings of A. floribunda.     

Influence of nursery soil amendments on water relations,root architectural development,and field performance of Douglas-fir transplants

This experiment evaluated the influence of manure, peat, and vermiculite incorporated at low and high rates (0.0118 and 0.0236 m³/m²) and under two soil moisture regimes on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedling (1+0 for 1+1) xylem water potential (_xylem), whole-plant growth, root architectural development, and subsequent field performance under fertilized and non-fertilized conditions. Trends in soil moisture retention were observed (high manure > high peat > control) but there were no differences in _xylem. Root length in the wetter soil moisture experiment was initially (three months) greatest for seedlings in high vermiculite and least in high manure but there were no differences among treatments at lifting (eight months). Mean height was greatest for seedlings grown in vermiculite and peat (wetter nursery experiment) after two field seasons. Field fertilization (35 g/seedling) with controlled-release fertilizer in the planting hole stimulated height growth initially, but decreased height and diameter growth during the second growing season. Dramatic improvements associated with the use of nursery soil amendments were not realized, but the failure to identify negative effects, a potential reduction in disease incidence, and improvement of nursery soil physical and chemical properties may justify their use.     

Stock quality and field performance of Pinus patula seedlings produced under two nursery growing regimes during seven different nursery production periods

Two types of containerized P. patula seedlings, referred to as hard and soft seedlings, were raised by droughting and different fertilizer applications. Hard seedlings were raised by applying half the water and a quarter of the fertilizer (0.01 g per seedling 21%N:7.1%P:14.2%K) applied to the soft seedlings. At the end of the nursery cultural treatments the two types of seedlings were morphologically distinct. Hard seedlings had lower heights, height to root collar diameter ratios and seedling dry masses than soft seedlings, but mortality was similar for both seedling types when planted during seven different production periods within the planting season on three sites which differed climatically and geologically. Correlations between mortality and height to root collar diameter ratio (r = 0.76), root to shoot ratio (r = 0.83) and root growth potential (r = --0.69) were obtained indicating that grading of seedlings on these parameters may improve survival. However, it was evident that survival could be significantly improved by identifying the best time of year and conditions for planting, as well as improving stock quality.     

Winter variation in physiological status of cold stored and freshly lifted semi-evergreen Quercus nigra seedlings

? Water oak (Quercus nigra L.) is a tardily deciduous species commonly planted in afforestation projects in the Lower Mississippi River Alluvial Valley, USA. Field performance is often marked by low survival rates and top dieback, which may be associated with poor physiological quality of planting stock.

? We investigated physiological status of cold stored (2–4 °C; CS) and freshly lifted (FL) seedlings during the period between lifting and planting (December — February). In mid-February, seedlings were transplanted into a controlled greenhouse environment for 90 d to evaluate post-transplant growth performance.

? Net photosynthetic rates were positive until late January (generally greater in CS seedlings) and became negative thereafter. FL seedlings generally had lower LT₅₀ values from freeze-induced electrolyte leakage (FIEL), reflecting greater cold hardiness. FIEL of foliage provided the best indicator of physiological status, though terminal buds may serve as a suitable substitute. All seedlings experienced top dieback following transplant; CS seedlings had less relative root-collar diameter, height, and root volume increments.

? Cold storing seedlings did not appear to prolong dormancy, increase stress resistance, or hold promise as a means to improve outplanting success. Regardless of storage regime, seedlings appeared to be most cold hardy and perhaps stress resistant until late January.

     

Herbicides and planting date affect early performance of container-grown and bare-root loblolly pine seedlings in Alabama

The survival of bare-root and container-grown loblolly pine (Pinus taeda L.) seedlings exceeded 90% when outplanted in March at two sites in Lee County, Alabama. At both sites, soil moisture and seedling survival were greater in March than in May. A March herbicide application reduced weed biomass by 75–80% at both sites. At the moist site, herbicide application did not affect survival. However, at the drier site, a reduction in weed biomass increased both the percent soil moisture and the survival of May-planted bare-root seedlings. When soil moisture at planting time was less than 13% on a dry weight basis container-grown seedlings survived better than bare-root seedlings. At both sites, reduced weed competition resulted in greater seedling heights and diameters.Alabama Experiment Station Journal Series No. 9-85802.     

A comparison of Riley encased methodology and traditional techniques for planting red mangroves (Rhizophora mangle)

The effectiveness of encasement and traditional techniques for planting red mangroves (Rhizophora mangle) in moderate to high wave energy environments was assessed. The three encasement types were the halflength PVC pipes, fulllength PVC pipes, and bamboo pipes. Plantings were conducted in August, 1997 at two locations in the Indian River Lagoon, Florida: Sebastian and Rocky Point. Furthermore, plantings were conducted in November, 1997 using fulllength encasements and conventional planting. Results indicate that seedlings planted within fulllength PVC encasements had the highest survivorship and growth because of their protection from waves and currents. Failure of seedlings within bamboo encasements seemed to be caused by insufficient light exposure. When comparing the two locations, a significantly greater growth was observed at the Sebastian location than at the Rocky Point location for the planting conducted in November, but not for those planted in August. No significant difference was observed in seedling survival when comparing those planted in August and November. However, there was a significantly greater growth in mangroves planted in August. With the exception of width of surf zone, there was no significant difference in the selected environmental parameters between the two locations.     

Root wrenching and lifting date of slash pine: Effects on morphology,survival, and growth

Slash pine (Pinus elliottii Engelm.) seedlings were subjected to three wrenching treatments: One root wrenching in early August; Three root wrenchings in early August, September, and October; and No wrenchings. Seedlings were then lifted on five dates between November and February based on the number of chilling hours accumulated. All wrenched seedlings had reduced shoot dry weight, smaller shoot-root ratio, and smaller stem diameter and height. These morphological differences translated into improved survival as well as increased diameter and height growth when measured one and two years after planting. Only seedlings wrenched three times demonstrated improved root fibrosity. Furthermore, only multiple wrenched stock showed greater resistance to drying imposed prior to planting. At the time of lifting, seedlings lifted latest had greater stem diameter, increased root dry weight and number of root tips, and improved shoot-root ratio. However, no survival differences were detected across lifts, and those seedlings lifted earliest demonstrated the best height and diameter growth.This paper is Journal Series No. R00695 of the Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611.     

Gas exchange,water relations and morphology of yellow-cedar seedlings and stecklings before planting and during field establishment

Information is lacking on how yellow-cedar (Chamaecyparis nootkatensis (D. Don.) Spach) stecklings compare with seedlings in their response to potentially limiting field site environmental conditions. Before planting, yellow-cedar seedlings and stecklings were characterized at 5 and 22°C root temperatures for gas exchange parameters (n=6), root growth capacity (n=12) and plant water movement (n=6) using a fully randomized design in a controlled environment growth room. Seedlings, compared with stecklings (t-test), showed a faster (p=0.01) recovery of net photosynthesis (P_n) and stomatal conductance (g_wv) after root temperature increased from 5 to 22°C. Seedlings had greater (p=0.05) root growth capacity (number of new roots 0.5 cm in length) than stecklings after 14 days at 22°C and after 14 days at 5°C followed by 15 days at 22°C. Seedlings had a lower (p=0.01) resistance to plant water movement measured after 29 days (14 days at 5°C followed by 15 days at 22°C root temperature).Seedlings and stecklings were planted on a coastal British Columbia field site and monitored for 1) morphological development and physiological response to ambient site conditions throughout the first growing season, and 2) physiological response to drought conditions during late summer. Both trials used a fully randomized design and stock type means were compared using t-tests (p=0.10, 0.05, and 0.01). Initially, seedlings were taller (p=0.01) than stecklings but otherwise morphologically similar (n=20). Over a 35 week period after planting, stecklings had greater incremental height growth, while seedlings produced a greater (p=0.01) number of roots extending out of the root plug. Seedlings and stecklings (n=6) had similar P_n and g_wv patterns under late spring environmental conditions. However, seedlings had greater P_n and g_wv under cold temperature (p=0.05 and p=0.1, respectively) and drought conditions (p=0.05 and p=0.01, respectively), but during conditions of high evaporative demand and adequate soil moisture, stecklings had greater (p=0.01) P_n and g_wv. Seedlings had higher (p=0.01) daily integrated shoot water potential values (D) at different times during the growing season, and maintained higher (p=0.05) predawn (_pd) shoot water-potential values, higher (D) (p=0.01) and lower (p=0.01) resistance to plant water movement (R_SPAC) during drought conditions.     

Height graded Eucalyptus tereticornis seedlings: One year field performance

Over the 1st year in the field, survivals, heights and diameters 2 cm above ground of Eucalyptus tereticornis seedlings were examined in relation to seedling height at the time of field planting. Seedling height grades of 10, 30, 50 and 60 cm were used and survival, heights and diameters were assessed.Survival percentages were generally high, ranging from 68.1% to 93.9% at 12 months of age, with the 60 cm height grade demonstrating superiority. At 12 months of age, mean heights for the 10 and 30 cm height grades were significantly less than those for the 50 and 60 cm height grades. There was less contrast between height grades in diameter attained after 12 months but a trend was apparent of more rapid diameter growth with increasing initial plant height.It is concluded that use of taller planting stock is a simple way to procure maximum possible early growth in Eucalyptus stands. However, the practise is appropriate only where rainfall patterns are sufficiently understood and a consistently humid period for seedlings to become well established in the field can be predicted. In less predictable or less well-known climates use of smaller, hardier, seedlings remains advisable.     

Growth of planted seedlings inside protective sleeves under strip openings of different widths in a post-agricultural forest

Many second growth forests have poor regeneration and in some spatial and economic context, such as post-agricultural forests, it may be beneficial to increase tree diversity. We planted seedlings of yellow birch (Betula alleghaniensis) and bur oak (Quercus macrocarpa) in strip openings of 3, 6 and 9 m width to control light. Individual mesh sleeves were used to reduce browsing pressure but they also reduced available light for seedlings: a large mesh and a small mesh sleeves were tested in each opening. Available light for seedlings ranged from 5 to 46% of full sunlight. First year growth was almost non-responsive to all treatments for both species, but birch showed strong responses during second year. Birches in the large mesh sleeve and the 9 m opening had the largest height and diameter increments, while those in the small mesh sleeve and the 3 m opening had the smallest increments. Small mesh sleeves increased the height over stem diameter ratio for both species. Treatments affected several other morphometric variables of birch but none of the oak. More time is needed to assert if bur oak can be a candidate species for enrichment planting. We recommend strip openings of 9 m width and large mesh sleeves, for protection against deer browsing, while controlling neighbouring competition, to promote artificial regeneration of hardwood species.     

Field performance of silver-birch planting-stock grown at different spacing and in containers of different volume

Silver birch seedlings were grown in two types of trays differing incell volume. For each kind of tray, three different spacings were achieved bygrowing seedlings in all, half or one quarter of the cells. The planting-stockso produced was out-planted at two forest sites and growth followed for fiveyears. Container size had a large effect on seedling morphology and on fieldperformance. Density also had a large effect on seedling morphology, but littleinfluence on performance. The tightest relationship of field performance was tothe mean dry weight of the stems of the planting stock (R² = 0.94).Mean height and sturdiness index, defined as diameter ÷height, were not correlated with performance. Of the non-destructivemeasurements, mean root-collar diameter was the most closely correlated withperformance.     

Root exposure effects on water relations of Eucalyptus nitens nursery stock

Bare-root seedlings of Eucalyptus nitens frequently exhibit water stress after planting resulting in leaf lamina damage and reduced leaf area. Two trials examined effects of root exposure and desiccation between lifting and transplanting on post-planting water relations, leaf retention and root growth. Plants with roots exposed on a glasshouse bench initially lost water rapidly. In one trial ₁ declined to around –2.0 MPa within 2.5 h, after which there was no further change with exposure up to 7.5 h. In the second trial, the initial decline in ₁ was more rapid, reaching below –2.0 MPa in the first hour, before remaining stable with continuing exposure up to 4.5 h. A further decline then continued to –4.0 MPa after 7.5 h.Two days after transplanting into potting mix, day – time leaf water potentials in all desiccation treatments had declined to near –2.0 MPa. Hydraulic resistivity, measured as leaf specific resistivity two days after transplanting, increased following exposure for greater than 2.5 h, but there was no further increase between 4.5 and 7.5 h. The increase in resistivity corresponded with leaf water potential declining below –2.0 MPa during exposure.In the second trial, increasing root exposure time resulted in decreased leaf area due to lamina necrosis. Root growth, measured three weeks after planting, was also reduced. and there was also a positive curvilinear relationship between leaf area remaining at three weeks and new root growth. The results are discussed in terms of hardiness and the management of E. nitens seedlings from nursery to plantation.     

Physiological recovery of freezer-stored white and Engelmann spruce seedlings planted following different thawing regimes

Logistic problems of large-scale reforestation necessitate freezer-storage of conifer seedlings. Frozen stock is typically thawed slowly at low temperatures for up to several weeks before shipping to the plantation site, but the necessity of this practice is questionable. Experiments were conducted to study effects of different thawing regimes on photosynthetic recovery, frost hardiness, water relations and growth initiation in interior spruce (white spruce (Picea glauca (Moench) Voss) and Engelmann spruce (Picea engelmannii Parry) hybrid complex). One year-old container-grown seedlings were planted after 9 days post-storage thawing at 5–15 °C or still frozen, directly from the freezer. During a 29 day observation period after planting, both groups showed changes in xylem water potential (_w), carbon fixation (A), stomatal conductance (g _s ), chlorophyll a fluorescence and xanthophyll cycle pigments. Treatment differences in fluorescence and pigments peaked within one hour after planting. All differences in _w, A, g _s , ratio of internal to external CO₂ concentration (C_i/C_a), fluorescence, pigments and root number disappeared after 5 to 8 days. Terminal bud burst occurred 2.6 days earlier in the pre-thawed seedlings. When seedlings were rapidly thawed in the dark at 21 °C they achieved maximum _w (–0.2 MPa) in 3–4 hour. When evaluated 45 min after planting, A, g _s , C_i/C_a and fluorescence values of rapidly thawed seedlings were intermediate between those for seedlings planted frozen or after 9 days slow thawing, showing that the recovery process was well underway a few hours after removal from the freezer. These results suggested that a suitable on-site operational protocol for rapid thawing might be to lay frozen bundles on the ground at ambient temperature overnight. In field trials of this method, rapidly thawed seedlings broke bud 3.3 days later than slowly thawed stock and also had greater frost hardiness at time of planting. Height, shoot and root mass did not differ after 3 months growth.     

Growing environment and container type influence field performance of black spruce container stock

Black spruce (Picea mariana [Mill.] B.S.P.) overwintered container crops produced in four container types spanning a range of container sizes and seedling rearing densities were compared for two consecutive years. In 1989 two growing environments (greenhouse and outdoors) were compared. In 1990 three growing environments (greenhouse, coldframe, and outdoors) and two hardening regimes (short day and natural) were compared. Seedlings were outplanted during the spring of 1989 and 1990 and total height and survival were assessed for five years.The outdoor-grown crop was shorter, smaller in root collar diameter and had less dry weight at time of planting than the crops produced in the greenhouse (1989 study) and in the greenhouse and coldframe (1990 study). Although the greenhouse crops in both studies were larger at time of planting, the outdoor-grown crops (1989 and 1990) and coldframe-grown crop (1990) displayed significantly greater annual height increment in the first two years after planting. The enhanced early height growth of the outdoor-grown crops may be due to the natural acclimation created by their growing environment.Seedlings grown in a large volume container, at a low plant density (441 plants/m²), had significantly larger root collar diameters and total dry weights at time of planting than seedlings grown in a smaller volume container at a high plant density. Stem volume production in the field was greater on seedlings from larger volume containers grown at low densities.     

Transplant Stress Index: A proposed method of quantifying planting check

This paper demonstrates a simple way of estimating the intensity and duration of planting check by examining height growth patterns. A transplant stress index is determined by the relationship between initial seedling height and subsequent height growth. This index is defined as the slope of a linear relationship between initial height and height increment. If the slope is negative, the plants (as a population) are said to be experiencing planting check. When the slope is approximately zero, the stock is said to be recovering from planting check. A steep positive slope suggests the stock has recovered from planting check. TSI values were determined for several conifers including Pinus elliottii Engelm. var. elliottii, Pinus taeda L., Pinus radiata D. Don, Picea sitchensis (Bongard) Carrière, and Larix× eurolepis Henry.     

Effect of thawing regime on growth and mortality of frozen-stored Norway spruce container seedlings planted in cold and warm soil

One-year-old frozen-stored Norway spruce (Picea abies (L.) Karst.) container seedlings were planted in a controlled environment providing an air temperature of 22°C and soil temperature of 9±1 or 18±1°C. At planting the root plugs were either frozen or had been thawing for 4 days at 9°C. During a 5-week growing period, in both cold and warm soil the root growth and height growth were less in frozen-planted seedlings than in thawed seedlings. In addition, frozen-planting delayed bud burst and increased mortality. Soil temperature, however, had no effect on bud burst or mortality. Low soil temperature retarded root growth of seedlings thawed before planting but resulted in both retarded root growth and height growth if root plugs were frozen when planted. These results indicate that planting Norway spruce seedlings with frozen root plugs constitutes a considerable risk for successful forest regeneration at soil temperatures normally prevailing in Fennoscandia in spring or early summer especially if the soil is dry at the time of the planting.     

Root volume as a grading criterion to improve field performance of Douglas-fir seedlings

Three seed sources of 2+0 Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings were graded into three root-volume categories (<9, 9–13, and >13 cm³) and outplanted to determine (i) differences in survival and growth after one and two growing seasons in the field, (ii) relationship(s) of seedling height after one and two seasons to preplanting nursery root volume, total fresh weight, root-collar diameter, and height, and (iii) differences in field performance due to fertilization at planting. Field survival was >90% among all root-volume categories. Seedlings in the largest category grew significantly better than those in the smaller two categories over two seasons. Apparently, a population of seedlings having a large proportion of high root volumes will outperform a population having a large proportion of low root volumes in the field. Fertilization at the time of planting had no effect on survival or growth because of shallow placement of the fertilizer pellet. The results suggest that targeting root volume, as well as height and diameter, is worthwhile where morphological quality must be maximized to improve field performance. Thus, root volume has potential for use as a criterion for grading seedlings.     

Eight-year performance of bareroot Douglas-fir and bareroot and plug western larch Seedlings following herbicide applications,northeast Oregon,USA

Plantation success in northeastern Oregon can be limited by poor survival for western larch (Larix occidentalis Nutt.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco) seedlings. Vegetation management treatments may increase soil moisture availability during the dry summer months, thereby increasing the probability of seedling survival. Chemical site preparation treatments were applied in spring 2007, summer 2007, and spring 2008 to determine if such treatments would improve survival and growth of bareroot Douglas-fir and bareroot and plug western larch seedlings on three sites near Elgin, Oregon. Although some herbicide treatments significantly increased survival, results were not consistent among sites. Overall, Douglas-fir had greater survival after 7–8 years than larch seedlings. Seedling size 7–8 years after planting was also highly variable among sites and treatments with larch seedlings being taller and larger than Douglas-fir seedlings, on the average. Size for all stock types was negatively correlated with vegetative cover and positively correlated with first-year soil moisture. Macro- and microclimatic conditions, including topography and soil depth, were likely contributors to differences in survival and growth.     

Influences of seedling size,container type and mammal browsing on the establishment of <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> in plantation forestry

Rapid early growth of tree seedlings is critical to the success of plantation establishment. We investigated the effects of seedling size (small and large) and container types (small [Lannen 121], medium [Lannen 81] and large [Forestry Tube]) in the nursery and the effects of mammal browsing after planting on growth of Eucalyptus globulus in Tasmania’s Southern Forests. After planting, seedlings were either exposed to browsing or protected from browsing by wire-mesh cages until age 6 months. Low browsing pressure resulted in around 20% and 5–10% of foliage being browsed in the large and small size categories, respectively, between 1 and 3 months after planting the uncaged treatment. 6 months after planting, height growth increment was lower, and 4 years after planting, mortality was higher in uncaged large than caged large seedling treatments. Six and twelve months after planting, seedlings raised in Forestry Tube containers had significantly greater height increment and root collar diameter relative to other treatments. By 4 years after planting, trees of the small seedling treatment had significantly greater diameter than those of the large seedling treatment, but there was no effect of container type treatment. Four years after planting there was no effect on diameter growth by browsing of <30% of foliage up to 3 months after planting, although there was greater incidence of double leaders in trees that had been browsed as seedlings. Small seedlings produced more growth 4 years after planting than large seedlings of E. globulus.