Evaluating desiccation sensitivity of Quercus rubra acorns using X-ray image analysis

2005 ◽  
Vol 35 (12) ◽  
pp. 2823-2831 ◽  
Author(s):  
Rosa C Goodman ◽  
Douglass F Jacobs ◽  
Robert P Karrfalt

Desiccation of northern red oak (Quercus rubra L.) acorns can impact seed viability. We examined use of X-ray image analysis of cotyledon damage in dried acorns to predict germination capacity and seedling vigor. Acorns collected from five half-sib sources were X-rayed before and after drying to one of four moisture content (MC) levels (30%, 25%, 20%, or 15%) or maintained as nondesiccated controls (35%–38% MC). X-ray images were scored qualitatively according to degree of cotyledon–cotyledon and cotyledon-pericarp separation. Following sowing, acorns were evaluated for number of days to reach each of three developmental stages (emergence of radicle, epicotyl, and first leaf flush) and growth for 80 d. Both MC and family significantly affected all variables. The percentage of acorns to reach each developmental stage, as well as final height and root-collar diameter declined with decreasing MC and dropped most notably between 20% and 15% MC. X-ray separation scores more effectively predicted the percentage of acorns to reach each of the first three developmental stages than MC level (R2 = 0.49–0.63 vs. 0.40–0.59). Our results confirm the recalcitrant nature of northern red oak acorns and demonstrate the potential of X-ray image analysis to provide a rapid and nondestructive means to successful predict acorn viability.

2017 ◽  
Vol 35 (1) ◽  
pp. 13-23 ◽  
Author(s):  
H. Zhu ◽  
H. Liu ◽  
Y. Shen ◽  
Hengyu Liu ◽  
R. H. Zondag

Abstract Multiple-row container-grown trees require specially designed sprayers to achieve efficient spray delivery. A five-port air-assisted sprayer with both automatic and manual control modes was developed to discharge adequate spray deposition inside multiple-row trees. The sprayer resulted from integration of a high-speed laser-scanning sensor with a sophisticated nozzle flow control system, an embedded computer with a touch screen, a Doppler speed sensor, a specially-designed algorithm and an air-assisted sprayer base. It was able to detect target tree presence and measure target tree size, shape and leaf density. The sprayer then controlled the spray output of each nozzle to match tree structures. The sprayer was tested for its sprayer deposition quality inside canopies in a four-row sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench) field and another six-row northern red oak (Quercus rubra L.) field. Tests were conducted with the sprayer in variable-rate application (VRA) and constant-rate application (CRA) modes. The average spray deposit on foliage of trees was 1.37±0.47 μL cm−2 from VRA and 1.29±0.42 μL cm−2 from CRA in linden, and was 2.15±0.57 μL cm−2 from VRA and 2.72±0.94 μL cm−2 from CRA in red oak, respectively. In comparison, spray coverage on foliage of trees was 19.8±3.0% from VRA and 20.9±4.3% from CRA in the linden trial, and was 27.9±3.7% from VRA and 30.5±5.4% from CRA, respectively, in the red oak trial. The newly developed air-assisted sprayer in both VRA and CRA modes would be able to discharge adequate spray deposition inside multiple-row tree plants while conserving pesticide. Index words: environmental protection, pest control, pesticide, precision sprayer, spray coverage. Species used in this study: sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench), northern red oak (Quercus rubra L.).


2003 ◽  
Vol 20 (2) ◽  
pp. 92-93
Author(s):  
Eric Heitzman ◽  
Adrian Grell

Abstract In 2001, we used power augers to plant 1-0 northern red oak (Quercus rubra) and white oak (Q. alba) seedlings in stony soils in Arkansas. After two growing seasons, red oak and white oak survival was 86% and 91%, respectively. Both species had only grown an average of 1 ft in height in 2 yr. North. J. Appl. For. 20(2):92–93.


2002 ◽  
Vol 19 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Terry L. Sharik ◽  
David S. Buckley

Abstract We documented patterns in the removal of planted northern red oak (Quercus rubra) acorns by rodents in red pine (Pinus resinosa) stands during a field study of oak regeneration in northern Lower Michigan. Each stand contained four overstory treatments assigned at random: clearcut, 25% cover, 50% cover, and uncut (control). Each level of canopy cover contained four randomly assigned understory treatments: shrub-layer removal, herb-layer removal, litter removal, and a control. Rodents removed acorns from 59% of the seed spots in the uncut control and 12% of the seed spots in the clearcut treatment. This five-fold difference was significant. Acorns were removed from 48% and 40% of the seed spots in the 75% and 50% canopy cover treatments, respectively. Differences in acorn removal between understory treatments were not significant. These results suggest that overstory vegetation treatments can influence the removal of planted acorns by rodents, which has implications for the use of direct seeding for artificially regenerating northern red oak.


2017 ◽  
Vol 19 (8) ◽  
pp. 2419-2425 ◽  
Author(s):  
Łukasz Myczko ◽  
Łukasz Dylewski ◽  
Artur Chrzanowski ◽  
Tim H. Sparks

1978 ◽  
Vol 110 (3) ◽  
pp. 241-244 ◽  
Author(s):  
G. A. Surgeoner ◽  
W. E. Wallner

AbstractTotal foliage consumption per larva of Heterocampa manteo (Doubleday) was 334 ± 49.3 cm2 of leaf area. Approximately 85% of the consumption occurred during the fifth larval stadium. There was no significant difference in consumption by H. manteo when fed northern red oak, Quercus rubra L., or white oak, Quercus alba L. Foliage consumption at 27 °C, 24 °C, and 21 °C did not differ significantly; but larvae reared at 15.5 °C consumed 42.6% less foliage. Larvae parasitized by Diradops bethunei (Cresson) consumed 61.3% less foliage than non-parasitized larvae reared at the same temperature. Two methods of predicting defoliation are discussed based upon larval foliage consumption data.


2016 ◽  
Vol 46 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Lisa W. Alexander ◽  
Keith E. Woeste

We developed a novel scoring system to assess spring phenology in a northern red oak (Quercus rubra L.) clonal seed orchard. The system was used to score from 304 to 364 ramets for three reproductive seasons and to place clones into early, intermediate, and late phenology classes. Although the absolute number of clones in each phenological class changed from year to year, the overall order of clonal flowering was highly stable (rs = 0.67, p < 0.001). Early-flowering clones flowered significantly longer than later flowering clones in all 3 years. Dichogamy was present in the orchard, with male flowers of a clone emerging from 1.4 to 3.0 d sooner than its female flowers. Mean dichogamy values for individual clones ranged from 0.0 to 4.9 (± 1.3) d. Year strongly influenced a clone’s dichogamy value (F = 6.0, p = 0.004), whereas genotype had no influence. The mean overall phenological synchronicity for the 3 years of observations was 0.30 ± 0.01 or about 30% overlap between the time when females were receptive and males were shedding pollen. This study represents the first effort to quantify phenology in an artificial population of northern red oak, and it provides a snapshot of the current relationship between temperature, phenology, and floral synchronization.


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