Root development and plantation establishment success

Application.Stecklings are a viable, alternative stock type to seedlings for reforestation of yellow-cedar. Under moderate field environmental conditions, both stock types will have similar performance capability. Under late summer conditions when soil moisture is high, stecklings will have better gas exchange capability. However, in areas having limiting soil moisture or cold soils during most of the growing season, seedlings may have better performance capability than stecklings. Thus, planting of seedlings should be favored over stecklings on reforestation sites where limiting environmental conditions predominate.Abstract. 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 (r-test), showed a faster (p = 0.01) recovery of net photosynthesis (PJ and stomata1 conductance (g,,) after root temperature increased from 5 to 22 "C. Seedlings had greater @ = 0.05) root growth capacity (number of new roots Z 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, and g,, patterns under late spring environmental conditions. However, seedlings had greater P, and g,, 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, and g,,. Seedlings had higher (p = 0.01) daily integrated shoot water potential values (DY) at different times during the 2 growing season, and maintained higher (p = 0.05) predawn (Y',) shoot water-potential values, higher (DY) (p = 0.01) and lower (p = 0.01) resistance to plant water movement (R,,,) during drought conditions.

Section: Resultsmentioning

confidence: 99%

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

Folk¹,

Grossnickle²,

Russell

1995

“…It has been reported that the relation between RGP measurements and both field survival and height growth is curved rather than straight (Burdett 1979, Burdett et al 1983. Therefore, we also determined whether adding quadratic terms to the best linear models for each evaluation improved their predictive ability.…”

Section: Statistical Analysmentioning

confidence: 99%

“…Numerous studies of the RGP approach have been conducted on a variety of species, and the correlations between RGP measurements and field survival have generally been high (Ritchie & Dunlap 1908;Ritchie 1985). There is less evidence linking RGP and field growth, but several studies have reported a positive correlation (von Althen & Webb 1978;Sutton 1980;Burdett et al 1983;.…”

Section: Introductionmentioning

confidence: 99%

Predicting field performance of Douglas-fir seedlings: comparison of root growth potential, vigor and plant moisture stress

McCreary

Duryea

1987

Application. The field performance of Douglas-fir seedlings can be strongly influenced by their physiological condition when they are outplanted. Seedlings damaged or with low vigor have a much greater chance of dying in the field, or at best, of growing slowly during initial establishment. Being able to identify and discard lots of poor quality can help prevent plantation failures by eliminating seedlings that have little or no chance for acceptable field growth or survival. Three methods of evaluating seedlings were compared, and all successfully predicted field performance. If such evaluations were applied to screen seedling lots prior to planting (especially those suspected of injury), reforestation in the Douglas-fir region could be improved.Abstract. Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings were evaluated by three measurements of seedling quality -root growth potential or RGP, vigor, and plant moisture stress or PMS -and the results were correlated with subsequent field performance. Measurements made by each method were significantly (p_< 0.05) correlated with first-and second-year survival and terminal height growth. Seedlings from lots that grew many new roots during a 28-day interval in a growth room (RGP evaluation) or that survived for 6 weeks in the growth room and initiated rapid budburst (vigor evaluation) or whose plant moisture stress values remained fairly constant during 1 week after potting (PMS evaluation) had the greatest field survival and height growth.The RGP evaluation was the best predictor of first-year height growth, while the vigor evaluation was the best predictor of first-and second-year survival. All evaluations predicted second-year height growth equally well.These results demonstrate that all three evaluations can be successfully used to predict field performance of Douglas-fir seedlings. Each has its advantages and limitations, and none can be considered "best".

“…The survival of a seedling depends to a large extent on the number and length of roots which are produced after transplanting (Sutton 1980;Struve and Moser 1984). Root growth capacity (RGC) tests which indicate the ability of the seedlings to produce new roots after transplanting, are known to show a strong correlation with seedling survival (Ritchie and Dunlop 1980;Burdett et al 1983). …”

Section: Introductionmentioning

confidence: 99%

The effect of seaweed concentrate on the growth of Pinus pinea seedlings

Atzmon

Staden

1994

Application. The use of seaweed concentrate (SWC) to accelerate root growth of Pinus pinea seedlings is described. This renewable natural product might be used to improve the root and shoot growth of forest seedlings. Foliar spraying or root drenching seedlings with SWC dilutions before transplanting in the field may reduce transplant shock.Abstract. Seedlings of Pinus pinea L. growing in plastic containers were treated with seaweed concentrate (SWC). Different concentrations of SWC were applied, 0 to 3 times, to the roots or shoots of the seedlings. Shoot application increased plant weight mainly by increasing shoot growth. This was manifested as increased shoot length and weight and a decrease in the root/shoot ratio. Root drenches did not change the total plant weight but it accelerated root growth and increased lateral root dry weight. Root growth capacity (RGC) tests for both shoot and root applications indicated an increase in root length and some increases in root number when applied as a root drench. This study indicates that root application of SWC improved seedling quality and increased the ability of seedlings to survive transplanting into pots.