The effect of wrenching on morphology and field performance of Douglas fir and loblolly pine seedlings

1976 ◽  
Vol 6 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Yasuomi Tanaka ◽  
J. D. Walstad ◽  
J. E. Borrecco
Keyword(s):  
Loblolly Pine ◽  
Lateral Roots ◽  
Field Performance ◽  
Dry Weight ◽  
Douglas Fir ◽  
Shoot Dry Weight ◽  
Percentage Points ◽  
Pine Seedlings ◽  
Nursery Stock ◽  
Second Year

Second-year Douglas fir and 1st-year loblolly pine nursery stock were undercut and wrenched while actively growing in nursery beds. Their morphology and field performance were compared with Douglas fir seedlings that had been undercut only and with loblolly pine seedlings that had been left intact.The treatment produced shorter, thinner-stemmed loblolly pine seedlings with reduced shoot dry weight. Height, diameter, and shoot dry weight of Douglas fir seedlings were virtually unaffected, but root dry weight was increased substantially. Development of fibrous lateral roots was stimulated in both species. As a consequence, shoot–root ratios were considerably improved, and the seedlings were better conditioned to withstand outplanting. On droughty sites, field survival of Douglas fir was increased by 20 percentage points and loblolly pine by 30 percentage points. Wrenching also extended by several weeks the fall and spring planting periods for loblolly pine and the fall planting period for Douglas fir.

scholarly journals Tolerance of Southern Pine Seedlings to Clopyralid

2000 ◽  
Vol 24 (1) ◽  
pp. 51-56 ◽  
Author(s):  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Dry Weight ◽  
Slash Pine ◽  
Southern Pine ◽  
Seedling Morphology ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Pine Seedlings ◽  
Pinus Taeda L ◽  
Pine Species

Abstract Tolerance of three pine species to postemergence applications of clopyralid was examined at ten southern nurseries over a 2 yr period. The herbicide was applied at various times during May, June, and July. At time of lifting, seedling morphology was evaluated (root-collar diameter, shoot height, root dry weight, and shoot dry weight). Loblolly pine (Pinus taeda L.), slash pine (P. elliottii Engelm. var. elliottii) and longleaf pine (P. palustdds Mill.) were tolerant to 210 to 840 g acid equivalent (ae)/ha. However, epinasty was occasionally observed on both loblolly pine and slash pine. The injury symptoms were ephemeral and seedlings appeared normal 3 months after treatment. Results from these tests suggest some pine species are tolerant to this herbicide at the seedling stage. As a result of this research, this herbicide can be legally used in many southern pine nurseries to control troublesome weeds such as sicklepod (Cassia obtusifolia L.), Florida beggerweed (Desmodium tortuosum [Sw.] DC.), horseweed (Erigeron canadensis L.) and other annual broadleaf weeds. South. J. Appl. For. 24(1):51-56.

Responses of loblolly pine to ozone and simulated acidic rain

1996 ◽  
Vol 26 (10) ◽  
pp. 1715-1723 ◽  
Author(s):  
R.A. Reinert ◽  
S.R. Shafer ◽  
G. Eason ◽  
S.J. Horton ◽  
M.M. Schoeneberger
Keyword(s):  
Loblolly Pine ◽  
Growth Parameters ◽  
Southeastern United States ◽  
Weight Ratio ◽  
Dry Weight ◽  
Stem Height ◽  
Shoot Dry Weight ◽  
Pine Seedlings ◽  
Acidic Rain ◽  
Simulated Rain

Acidic rain and ozone (O3) may have serious consequences on the growth and development of loblolly pine (Pinustaeda L.), a tree species of major economic importance in the southeastern United States. In two independent studies, seedlings of open-pollinated families of loblolly pine were exposed to five concentrations of O3 (0, 80, 160, 240, or 320 nL•L−1) and three simulated rain acidities (pH 5.3, 4.3, or 3.3). Following 23 weeks of growth (12 weeks in charcoal-filtered air and 11 weeks of O3 and simulated acidic rain exposures), stem height, secondary needle dry weight, top and total seedling dry weight, and root/shoot dry weight ratio all were related negatively and linearly with O3 concentration. Stem diameter and root dry weight were also suppressed by O3. Suppression of the growth parameters ranged from 14 to 35% for the greatest O3 concentration. Acidity of simulated rain did not affect seedlings, nor did it affect seedling responses to O3. Results indicate that acid rain probably has little effect on growth of loblolly pine seedlings, but O3 can suppress growth to varying degrees depending on family.

Cell Size and Pretransplant Nutritional Conditioning Influences Early Vine Growth and Yield of Transplanted Watermelon

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 594e-594
Author(s):  
Charles J. Graham
Keyword(s):  
Cell Volume ◽  
Significant Influence ◽  
Field Performance ◽  
Dry Weight ◽  
Soluble Solids ◽  
Growth And Yield ◽  
Average Weight ◽  
Shoot Dry Weight ◽  
Solids Concentration ◽  
Soluble Solids Concentration

Research is needed to better understand the influence of cell volume and fertility on watermelon transplant size and field performance in order to determine the most economic production practices. `Jubilee' watermelon transplants were grown using a 4 x 4 factorial experimental design consisting of 4 cell volumes (30.7, 65.5, 147.5, and 349.6 cm3) and 4 fertility rates (0, 1/4, 1/2, and full-strength Hoagland's solution). Transplant shoot dry weight significantly increased as cell volume and fertility increased. Increasing cell volume linearly increased watermelon number/ha and tons/ha for early and total harvest in 1995. The average weight per watermelon significantly increased for early-harvested fruit but not for total harvest as cell volume increased in 1995. Soluble solids concentration linearly increased with increasing cell volume for early and total harvests in 1995. Cell volume had no significant influence on the harvest parameters measured in 1997. In 1995, increasing fertility linearly increased watermelon number/ha and tons/ha for early harvests. Increasing fertility increased the soluble solids concentration linearly for early-harvested watermelons in 1997 but not in 1995. Fertility rate had no significant influence on any of the other harvest parameters measured in 1995 and 1997. The growing conditions and disease pressure in 1997 reduced melons/ha, yield, and soluble solids content when compared to 1995 values. The half-strength Hoagland's solution produced the greatest number of watermelons/ha, tons/ha, and the highest soluble solids concentration in 1995 and 1997. Pretransplant nutritional conditioning had no significant effect on total `Jubilee' watermelon production in Louisiana for 1995 and 1997.

The relationship between multiple leaders and mechanical and frost damage to the apical meristem of Scots pine seedlings

1990 ◽  
Vol 20 (3) ◽  
pp. 280-284 ◽  
Author(s):  
Jarmo K. Holopainen
Keyword(s):  
Scots Pine ◽  
Apical Meristem ◽  
Dry Weight ◽  
Frost Damage ◽  
Night Temperature ◽  
Shoot Dry Weight ◽  
Frost Injury ◽  
Pine Seedlings ◽  
Before And After ◽  
Multiple Leaders

The responses of young Scots pine seedlings to mechanical apical meristem damage before and after 4 nights exposure to minimum night temperatures of −2.2 and −6.7 °C in controlled environment growth chambers were compared with control seedlings that were subjected or not to apical meristem damage and exposed to a minimum night temperature of 12 °C. The feeding damage caused by Lygus bugs was simulated by piercing the apical meristem of young pine seedlings with a hypodermic syringe needle and injecting a small drop of distilled water into the wound. At −6.7 °C increased numbers of dead seedlings were found. The proportion of seedlings with multiple leaders greatly increased after piercing, and about half of the seedlings subjected to the apical meristem damage had multiple leaders. The proportion of seedlings with multiple leaders and the number of leader shoots per seedling did not differ among seedlings subjected to apical meristem damage before or after the frost exposure. Short and twisted primary needles occurred in the basal parts of the new shoots in the seedlings with multiple leaders. Seedlings with necrotic needles were most often found after exposure to the night temperature of −6.7 °C. Shoot dry weight and length were significantly lower in seedlings subjected to apical meristem damage after frost exposure than in seedlings subjected to apical meristem damage before frost exposure or to no frost exposure. The results suggest that an increased reduction in growth is to be expected if Lygus bug attacks occur on pine seedlings that already suffer from frost injury.

scholarly journals Growth of mango (Mangifera indica L.) rootstocks as influenced by pre-sowing treatments

2017 ◽  
Vol 9 (1) ◽  
pp. 582-586
Author(s):  
R. J. Patel ◽  
T. R. Ahlawat ◽  
A. I. Patel ◽  
J. J. Amarcholi ◽  
B. B. Patel ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Root Length ◽  
Mangifera Indica ◽  
Lateral Roots ◽  
Weight Ratio ◽  
Dry Weight ◽  
Shoot Length ◽  
Shoot Dry Weight ◽  
Survival Percentage ◽  
Total Dry Weight

An experiment was carried out at Navsari Agricultural University, Navsari during 2014 to evaluate the effect of pre-sowing treatments on survival percentage and growth of mango rootstocks. Mango stones were soaked in aqueous solutions of GA3 (100 and 200 ppm), Beejamruth (2 % and 3 %) and Thiourea (1 % and 2 %) for 12 and 24 hours. The trial was evaluated in Completely Randomized Design based on factorial concept and the treatments were replicated thrice. Imposition of treatments led to significant differences at 5 % level of significance for all parameters chosen in this study. Mango stones when treated with Thiourea at 1 % had the maximum shoot length (49.93 cm), root length (34.38 cm), shoot dry weight (21.08 g) and total dry weight (26.36 g). The highest number of lateral roots (10.90) and survival percentage (64.17) was observed in mango stones dipped in 100 ppm GA3. Between the two soaking duration, soaking mango stones for 24 hours recorded higher values for shoot length (45.03 cm), root length (32.79 cm), number of lateral roots (9.83), survival percentage (62.72), shoot root fresh weight ratio (4.30), shoot dry weight (21.33 g), total dry weight (26.28 g) and shoot root dry weight ratio (4.32). Thus, survival percentage and growth of mango rootstocks can be substantially improved by soaking mango stones in aqueous solutions of 100 ppm GA3 or Thiourea at 1 % for 24 hours before sowing.

scholarly journals The Association of a Longidorus Species with Stunting and Root Damage of Loblolly Pine (Pinus taeda L.) Seedlings

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 803-807 ◽  
Author(s):  
Stephen W. Fraedrich ◽  
Michelle M. Cram
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Dry Weight ◽  
Forest Tree ◽  
Root Weight ◽  
Extraction Techniques ◽  
Seedling Root ◽  
Pine Seedlings ◽  
Proper Diagnosis ◽  
Pinus Taeda L

A Longidorus species was consistently associated with patches of stunted and chlorotic loblolly pine seedlings at a forest-tree nursery in Georgia. Seedlings from affected areas had poorly developed root systems that lacked lateral and feeder roots. Longidorus population densities in composite soil samples from the margins of patches ranged from 9 to 67 nematodes per 100 cm3 of soil. In a growth chamber experiment, seedling root dry weight decreased with respect to the initial Longidorus dose as well as the final Longidorus populations in containers. The dry root weight of seedlings were 0.117, 0.090, 0.066, and 0.065 g in containers initially infested with 0, 50, 100, and 200 Longidorus, respectively. Lateral and fine roots were lacking on seedlings at the highest doses. Populations of Longidorus increased in all containers during the experiment. Damage to loblolly pine seedlings caused by Longidorus is a previously undescribed problem in southern pine nurseries. Proper diagnosis of the problem by nematode testing laboratories may require the use of extraction techniques specific for larger nematodes such as Longidorus.

Growth and Development of Bigroot Morningglory (Ipomoea pandurata)

1991 ◽  
Vol 5 (4) ◽  
pp. 805-810 ◽  
Author(s):  
Michael J. Horak ◽  
Loyd M. Wax
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Dry Weight ◽  
First Year ◽  
Growing Degree Days ◽  
Degree Days ◽  
Root:Shoot Ratio ◽  
Shoot Dry Weight ◽  
Second Year ◽  
Final Harvest

Growth and development of bigroot morningglory was observed and quantified. Emergence occurred 75 ± 5 growing degree days (GDD) after seeding. Flower and seed production began 630 ± 20 GDD after emergence and continued until the first frost killed the shoots. Seedlings needed approximately 460 GDD of growth to become perennial. In the second year of growth, plants emerged in early May and flowered within 425 ± 50 GDD. Shoot dry weight accumulation in first-year plants was 3.5 g for the first 600 GDD after which a fifteenfold increase in dry weight occurred. Root growth followed the same pattern, however the large increase in dry weight occurred approximately 300 GDD later than that of the shoots. The root:shoot ratio was 0.2 to 0.3 for the first 900 GDD and increased to greater than 1.0 by the final harvest.

scholarly journals Fungicides Improve Field Performance of Stored Loblolly and Longleaf Pine Seedlings

1996 ◽  
Vol 20 (1) ◽  
pp. 5-9 ◽  
Author(s):  
John C. Brissette ◽  
James P. Barnett ◽  
John P. Jones
Keyword(s):  
Loblolly Pine ◽  
Cold Storage ◽  
Untreated Control ◽  
Longleaf Pine ◽  
Field Performance ◽  
Storage Duration ◽  
Fungicide Application ◽  
Total Height ◽  
Pine Seedlings

Abstract Seedlings of loblolly and longleaf pine lifted in December, January, and February were treated with either benomyl or ridomil before cold storage. Along with an untreated control, they were planted after cold storage of less than 1 wk, 3 wk, and 6 wk. Survival was measured in mid-June after planting, and after 1 and 4 yr in the field. Total height was measured after 4 yr. The fungicide application increased survival of both species lifted in December or February and was beneficial to longleaf pine seedlings regardless of storage duration. Fungicide-treated longleaf pine seedlings had greater mean 4 yr height than the controls, but fungicides did not affect the height of loblolly pine. South. J. Appl. For. 20(1): 5-9.

scholarly journals Needle-Clipping Longleaf Pine and Top-Pruning Loblolly Pine in Bareroot Nurseries

1998 ◽  
Vol 22 (4) ◽  
pp. 235-240 ◽  
Author(s):  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Seedling Survival ◽  
Longleaf Pine ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Root Weight Ratio ◽  
Root Dry Weight ◽  
Percentage Points ◽  
Average Survival

Abstract Studies have shown that clipping needles of longleaf pine before outplanting can increase average seedling survival by 13 percentage points. Under some situations, the increase in survival might be due to a reduction in transpiration. For loblolly pine, top-pruning in the nursery might increase average survival by 6 percentage points. Benefits of pruning appear greater when seedlings experience stress after planting and when nonpruned seedlings have low root weight ratios (root dry weight/total seedling dry weight). On some droughty sites, a seedling with a 0.3 root weight ratio might have an 80% chance of survival, while a seedling with a 0.2 root weight ratio might only have a 53% chance of survival. In most studies where heights were measured after 3 yr in the field, pruned seedlings were the same height as nonpruned seedlings (± 7 cm). South. J. Appl. For. 22(4):235-240.

Improving Field Performance of Southern Pine Seedlings by Treating with Fungicides before Storage

1988 ◽  
Vol 12 (4) ◽  
pp. 281-285 ◽  
Author(s):  
James P. Barnett ◽  
John C. Brissette ◽  
Albert G. Kais ◽  
John P. Jones
Keyword(s):  
Loblolly Pine ◽  
Cold Storage ◽  
Storage Time ◽  
Seedling Survival ◽  
Field Performance ◽  
Pathogenic Microorganisms ◽  
Shortleaf Pine ◽  
Southern Pine ◽  
Pine Seedlings ◽  
Clay Slurry

Abstract Field survival of longleaf, shortleaf, slash, and loblolly pine seedlings that had benomyl incorporated into the packing medium was markedly improved over that of clay-slurry controls. The more difficult to store seedlings of longleaf and shortleaf pine had greater magnitudes of response than more easily stored loblolly and slash pines. The decrease in seedling survival with storage time is related to a rapid increase in pathogenic microorganisms in cold storage. Although Benlate® ¹ 50WP is now registered for this use, the most effective fungicide dosage rates for routine use with different southern pine species must still be determined. South. J. Appl. For. 12(4):281-285.

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